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Ref: P3450026 Issue: Issue 1.0 Date: 10th June 2005 Page:

LESSONS LEARNED FROM THE PLANETARY PROTECTION ACTIVITIES ON THE BEAGLE 2

SPACECRAFT

Issue 1.0

June 2005

ESA CR(P)-4482

ESA commissioned this report from the Beagle 2 project team to provide a review of the planetary protection activities associated with the Beagle 2 spacecraft. This review is supposed to focus on the lessons learned from the implementation of the COSPAR planetary protection requirements, including the decision making process in selecting the appropriate implementation strategy for the planetary protection requirements, operation of the Aseptic Assembly Facility (AAF), and the views of participating scientists, engineers, and managers. It is not part of the mandatory planetary protection documentation. The objective of this report is to provide the decision makers for future Mars missions with information regarding the possible use and limitations of the planetary protection implementation strategies selected by the Beagle 2 project team. There are a number of valuable lessons to be learnt from this review - from the selection of materials to be used in the cleanroom environment and for the spacecraft, to the training of personnel and operation of the AIV process. This review is particularly timely considering ongoing activities for future missions to Mars. Gerhard Kminek European Space Agency Planetary Protection Officer, D/HME

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Issue: Issue 1.0 Date: 10th June 2005 Page: Page 2 of 103

LESSONS LEARNED FROM THE PLANETARY PROTECTION ACTIVITIES ON THE BEAGLE 2 SPACECRAFT

DOCUMENT CHANGE RECORD

Issue /

Revision

Date

Changes

Description

Draft 21st June 2004

For discussion

Draft 2 25th January 2005 Additional Content Added

Initial Submission

Draft 3 25th April 2005 CTP review Permission to submit to ESA

Draft 4 15th May 2005 Additional Content Added

Completed document submission

Issue 1.0 10th June 2005 Minor corrections Document submission

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TABLE OF CONTENTS

1. INTRODUCTION 2. REVIEW OF THE PLANETARY PROTECTION HISTORICAL BACKGROUND AS APPLICABLE TO BEAGLE 2 3. REVIEW OF DEVELOPMENT OF THE BEAGLE 2 PLANETARY

PROTECTION PLAN AND ITS IMPLEMENTATION 4. REVIEW OF DESIGN AND CONSTRUCTION OF THE BEAGLE 2 ASEPTIC ASSEMBLY FACILITY 5. REVIEW OF OPERATION OF THE BEAGLE 2 ASEPTIC ASSEMBLY FACILITY 6. REVIEW OF MONITORING OF THE BEAGLE 2 SPACECRAFT AND ASEPTIC ASSEMBLY FACILITY 7. REVIEW OF “OFF SITE” PLANETARY PROTECTION ACTIVITIES 8. REVIEW OF THE BIOBURDEN ANALYSIS OF BEAGLE 2 9. SUMMARY AND CONCLUSIONS 10. APPENDICES

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1. INTRODUCTION

1.1 LESSONS LEARNED FROM THE PLANETARY PROTECTION ACTIVITIES ON THE BEAGLE 2 SPACECRAFT REPORT This document was commissioned by ESA to provide a review of the planetary protection activities associated with the Beagle 2 mission to Mars, to learn lessons, where such can be learnt, to take forward for subsequent Mars exploration missions and to other solar system bodies where there is a significant planetary protection component to the mission requirements (essentially Category III, IV and V missions, based on the de Vincenzi et al. [1983] classification). It describes the issues affecting the Beagle 2 project pertaining at the time of the mission, the solutions adopted and the rationale, where appropriate. Beagle 2 was the lander component of the European Space Agency’s Mars Express mission, which attempted to land on the martian surface on 25th December 2003. Intended to address the age old question of whether there is life, past or present, on Mars, the lander has not been in contact since separation from the Mars Express orbiter on 19th December 2003. Despite the lack of data from the spacecraft, the mission did of course comply in full with the planetary protection requirements for a mission category of its type. The approach to Beagle 2 planetary protection was unique, and there are significant lessons to be learnt from the planetary protection achievements of the Beagle 2 team with regard to future planetary lander missions. In commissioning this report, ESA considered it to be important to solicit the views of the engineers working in the cleanroom and the designers/managers on the spacecraft/AIT side, as well as the Planetary Protection team from the Open University. Acknowledgement is given to the “sample” of eight current and former EADS-Astrium employees, whose interviews added their views and experiences of Beagle 2 Planetary Protection Implementation in the development of this document.

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1.2 ACRONYMS AND ABBREVIATIONS

AAA Aseptic Assembly Area – class 10 area within the AAF AAF Aseptic Assembly Facility AIT Assembly, Integration and Test (of the spacecraft) AIV Assembly, Integration and Verification (of the spacecraft) ATP Adenosine Triphosphate AWE Atomic Weapons Establishment - Aldermaston CAD Computer Aided Design CDR Critical Design Review COSPAR Committee for Space Research CRT Cathode Ray Tube cu.ft. Cubic feet (reference volume for cleanroom air) EDLS Entry, Descent and Landing System EGSE Electrical Ground Support Equipment EM Engineering Model ESA European Space Agency ESD Electrostatic Discharge FM Flight Model FMS Facility Monitoring Systems (company) GAP Gas Analysis Package (in lander) HEPA High Efficiency Particulate Air (filters) HPF Hazardous Processing Facility (at Baikonur Cosmodrome) IPA Isopropyl Alcohol (Propan-2-ol) IPR Intellectual Property Rights IR Infra-red ISO International Standards Organisation IT Information Technology ITT Invitation to tender LAL Limulus Amoebocyte Lysate MEx Mars Express (spacecraft) MGSE Mechanical Ground Support Equipment MLI Multi-layer Insulation NASA National Aeronautical & Space Administration (USA) OU Open University QM Qualification model QSCADA Trade name of the AAF building control software PA Product Assurance PC Personal Computer PCM Phase Change Material PCR Polymerase Chain Reaction PP Planetary Protection PPF Payload Processing Facility (at Baikonur Cosmodrome) PPIP Planetary Protection Implementation Plan PPM Planetary Protection Manager PPP Planetary Protection Plan PSSRI Planetary & Space Sciences Research Institute, OU RAL Rutherford Appleton Laboratory RF Radio Frequency

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RSSL Reading Scientific Services Ltd SHADS Sample Handling And Distribution System SUEM Spin Up and Eject Mechanism TP Thermal Protection UCIF Upper Composite Integration Facility (at Baikonur Cosmodrome) UK United Kingdom UKAS United Kingdom Accreditation Service ULPA Ultra Low Particulate Air uv ultraviolet (light wavelength range) VOC Volatile Organic Compound

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1.3 GLOSSARY OF TERMS

Bioload Number of colony forming units from a heat shocked sample, aerobically assayed per NASA document NHB5340.1B.

Bioload Reduction Processes to reduce the viable microbial population on an

instrument to an acceptable limit which, in the case of Beagle 2, is defined as that from which a statistical sample has no more than 300 spores/m2.

Bioseal A barrier surrounding a spacecraft, capsule, system or

component which prevents biological recontamination subsequent to microbial reduction procedures.

Microbiological Monitoring The data management and surveillance activities which are

performed so that the biological condition of an item of interest may be verified.

Chemical Cleanliness Reduction in the number of contaminants derived from

biological or abiotic sources, the chemical components of which could compromise analytical results of the Science Mission.

Component A small unit of the lander which can be considered in terms of

its material components. Encapsulated (In context of microbial contamination) Description of live

organisms embedded in solid materials which must be accounted for planetary protection purposes.

Encapsulation (In context of spacecraft assembly) Enclosure of the spacecraft

in the rocket fairing. Mated (In context of microbial contamination) Description of location

of live organisms trapped between mated faces in an assembled subsystem which must be accounted for planetary protection purposes.

Planetary Protection Avoidance of contaminating a planet with foreign life forms so

that the planet is maintained in its pristine state during the period of scientific investigation (forward contamination). The avoidance of contaminating the Earth’s biosphere with extraterrestrial agents that might have a deleterious effect (backward contamination – applicable to sample / hardware return missions).

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Sterilisation A process by which bioload reduction is achieved. Sterility A quantitative estimate of the presence/absence of bioload,

usually expressed as a number of organisms present, or the statistical probability of an item being contaminated with a viable organism.

Subsystem A basic constituent system of the lander, made up of smaller

components. Surface (In context of microbial contamination) Description of location

live organisms on accessible surfaces of solid materials which must be accounted for planetary protection purposes.

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2. REVIEW OF THE PLANETARY PROTECTION HISTORICAL BACKGROUND AS APPLICABLE TO

BEAGLE 2 General historical overviews of planetary protection can be readily found, for example, in Rummel & Billings (2004). More specifically, the approach behind the current COSPAR requirements for planetary protection, to which spacefaring nations need to adhere, arises from work done in the early 1980s and published by De Vincenzi et al. (1983, 1995). This work has recently been updated to form the current (2002) policy (Rummel et al. [2002]), and requirements are shown in Table 2.1. At the time the Beagle 2 mission was being planned, planetary protection activity was principally based on mission heritage from the Viking era. The Viking landers themselves were terminally sterilised. That is, at the end of the assembly phase, the landers were subjected to a high temperature dry heat sterilisation process, rendering them effectively sterile (bioburden close to 0 – statistically 30 spore forming microorganisms were accounted at launch). The scientific findings of the Viking landers were that the martian environment is inhospitable to then-known terrestrial microorganisms. COSPAR requirements for martian landers were then relaxed to the level of contamination present on the Viking landers before sterilisation, ie 300,000 spore forming microorganisms in total, at an average density of below 300 microorganisms/m2 for a single landing event. However, to achieve even this level of cleanliness is not straightforward and requires spacecraft assembly in a cleanroom environment, with a set of monitoring and cleanliness criteria over and well above that normally adopted for spacecraft assembly, for example with missions into low earth orbit.

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Table 2.1. Categories for Solar System Bodies and Types of Missions (Excerpted from COSPAR Planetary Protection Policy as adopted 2002) Category I Category II Category III Category IV Category V Type of Mission Any but

Earth Return Any but Earth Return

No direct contact (flyby, some orbiters)

Direct contact (lander, probe, some orbiters)

Earth return

Target Body See Appendix

See Appendix See Appendix See Appendix See Appendix

Degree of Concern

None Record of planned impact probability and contamination control measures

Limit on impact probability Passive bioload control

Limit on probability of non-nominal impact Limit on bioload (active control)

If restricted Earth return:

• No impact on Earth or Moon;

• Returned hardware sterile;

• Containment of any sample.

Representative Range of Requirements

None Documentation only (all brief):

• PP plan • Pre-launch

report • Post-launch

report • Post-encounter

report • End-of-mission

report

Documentation (Category II plus)

• Contamination control

• Organics inventory (as necessary)

Implementing procedures such as:

• Trajectory biasing

• Cleanroom • Bioload

reduction (as necessary)

Documentation (Category II plus)

• Pc analysis plan • Microbial

reduction plan • Microbial assay

plan • Organics

inventory Implementing

procedures such as:

• Trajectory biasing

• Cleanroom • Bioload

reduction • Partial

sterilization of contacting hardware (as necessary)

• Bioshield Monitoring of

bioload via bioassay

Outbound Same category as

target body/ outbound mission

Inbound If restricted Earth

return: • Documentation

(Category II plus)

• Pc analysis plan • Microbial

reduction plan • Microbial assay

plan • Trajectory

biasing • Sterile or

contained returned hardware

• Continual monitoring of project activities

• Project advanced studies/research.

If unrestricted Earth

return: • None

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Since Viking, all NASA (Pathfinder, Mars Polar Lander, Spirit and Opportunity) and ESA (Mars 96, Beagle 2) missions to the surface of Mars have all been category IVa missions. By contrast, the orbiter missions during this period (eg Mars Global Surveyor, Mars Odyssey, Mars Express) have all been category III missions. It is also worth considering the mission scenario in the context of the Nozomi experience: the Japanese were “forced” to terminate their mission when malfunctions on the spacecraft made it impossible to guarantee (at the required 10-4 probability level) that the non-sterilised probe would not crash into the target planet. As the scientific studies on Beagle 2 could potentially be affected or compromised by contaminants carried by the spacecraft. The Beagle 2 craft had additional requirements in terms of chemical cleanliness over and above those of Planetary Protection, which are detailed in the Planetary Protection Implementation Plan, but basically involved materials control in the lander and AAF, together with monitoring of the organic compounds that are “permitted” in the spacecraft. These requirements impacted the environmental control for the spacecraft from beyond the assembly phase in Milton Keynes, through fit check at Toulouse, to launch from the Baikonur Cosmodrome in Kazakhstan. A schematic of the campaign and reporting of how the requirements were met is given in the Beagle 2 Planetary Protection Post Launch Report (BGL-OU-RE-009).

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2.1 BEAGLE 2 CLASSIFICATION Following consultation and as part of the formal CDR process for Beagle 2 in September 2000, the Planetary Protection Plan (BGL-OU-PL-005) was reviewed by ESA and NASA representatives. It was agreed that the mission architecture and science mission requirements required the spacecraft be assigned the COSPAR IVa mission category, under the guidelines NPG8020.12B (now updated as NPR8020.12C) produced by NASA. 2.1.1 Beagle 2 Lander Classification – Revision However, in the opinion of the Beagle 2 Science team, neither the precautions of the Category IVa or the more stringent Category IVb planetary protection requirements could guarantee the scientific integrity of the data from the organic geochemistry/gas analysis package (GAP). In particular, the presence of any sterilised microorganisms would be as detrimental as viable ones in contact with the sample handling and analysis devices (SHADS). Therefore Beagle 2 met an alternative classification, Category IVa+, based on Category IVa, in which the team followed additional procedures to eliminate as far as possible any interference from microbial debris. This approach to minimise possible interference from carbonaceous contamination (microbial, biogenic or abiotic e.g. elemental carbon or carbonate) was to implement three additional procedures, listed in order of increasing efficacy: • Following sterilisation, all components / materials in contact with the SHADS will be

aseptically cleaned to remove any residual material produced by bioburden reduction. • Irrespective of their abundance, all carbonaceous materials and those containing nitrogen

which are exposed in the vicinity of the analytical and sample handling systems and hence could compromise scientific interpretations were listed, sampled and analysed in the laboratory by a similar procedure to that which Beagle 2 will employ on the surface of Mars. Samples of all such materials were inventoried, stored and analytical data equivalent to experiments to be performed on the surface recorded.

• The most critical parts of Beagle 2 were to have been subject to ‘blank’ studies in situ

immediately prior to sample analysis on the martian surface. From these requirements grew the requirement to assemble the lander in a facility other than a standard (albeit clean) aerospace class 100,000 environment, though undoubtedly there was great additional benefit in the management of Planetary Protection.

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2.2 SUMMARY OF BEAGLE 2 REQUIREMENTS In general, the surface microbial bioload of the Beagle 2 (EDLS, aeroshell and lander) at launch and the procedures employed to control / microbially assay Beagle 2 was required to be similar to the Viking lander before its terminal sterilisation, i.e. • average bioload density of 300 viable spores m2, • 300,000 viable spores for the total lander. The microbial bioload was determined by microbial assay as defined by NASA document NHB5340.1B, utilising where appropriate European equivalents (see Chapter 7).

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2.3 OTHER APPLIED PLANETARY PROTECTION SPECIFICATIONS Further PP specifications outlined in NASA document NPG8020.12B were applied to the Beagle 2 mission and were employed in the implementation of the PP. These include: • Time-temperature for sterility

A surface, the temperature of which exceeds 500 °C for more than 0.5 seconds, may be considered sterile (viable microbial bioload statistically zero).

• D value, Z value

Dry heat microbial reduction at a relative humidity less than 25% (referenced to 0°C and 1 atmosphere) for spores has a D value (i.e. the time for a 10-fold reduction at that temperature) at 125°C of 0.5 hour for free surfaces, and 1 hour for mated surfaces. The corresponding Z value (i.e. the change in temperature for a factor of 10 change in the D value) of 21°C, for the temperature interval 104°C-146°C.

• Hardy organisms

The maximum reduction factor that may be taken for a dry heat microbial reduction is 104 this parameter specification is based on an assumed fraction of hardy organisms (i.e. of higher resistance to the process than the general microbial population) of 10-3 and a reduction of only 0.1 in a nominal sterilisation cycle.

• Surface microbial density

Various parameter specifications were permitted for microbial bioload estimates where assays are not feasible; these may also eliminated the need for assay. For example: Surface bioload density: 1x105 spores m-2 uncontrolled manufacturing 1x104 spores m-2 class 100,000 clean room with normal controls 1x103 spores m-2 class 100,000 clean room with stringent controls 5x102 spores m-2 class 10,000 clean room with normal controls 5x101 spores m-2 class 10,000 clean room with stringent controls (Below this level, further reductions are not possible due to the erratic/non-uniform nature of microbial contamination, and the ever-present risk of “gross contamination” by the activities of cleanroom operators and operations.) Microbial bioload density: 150 spores cm-3 encapsulated non-metallic materials (this is the most stringent NASA

requirement for bioload – lower could have been claimed had the project enough time to obtain real data/realistic estimates for components from many and varied sources, and subjected to many and varied processes during manufacture).

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2.4 POST-BEAGLE 2 PLANETARY PROTECTION DEVELOPMENTS From 2002, the current COSPAR policy introduced new requirements, which grew from the recognition of the diversity and tenacity of life on earth. A new mission sub-category, IVc, was created, which places additional requirements on the Project teams operating post-Beagle 2, as follows (excerpted from the COSPAR policy):

“Category IVc. For missions which investigate martian special regions (see definition below), even if they do not include life detection experiments, all of the requirements of Category IVa apply, along with the following requirement: • Case 1. If the landing site is within the special region, the entire landed system shall

be sterilized at least to the Viking post-sterilization biological burden levels. • Case 2. If the special region is accessed though horizontal or vertical mobility, either

the entire landed system shall be sterilized to the Viking post-sterilization biological burden levels, OR the subsystems which directly contact the special region shall be sterilized to these levels, and a method of preventing their recontamination prior to accessing the special region shall be provided.

If an off-nominal condition (such as a hard landing) would cause a high probability of inadvertent biological contamination of the special region by the spacecraft, the entire landed system must be sterilized to the Viking post-sterilization biological burden levels. Definition of “Special Region”

A Special Region is defined as a region within which terrestrial organisms are likely to propagate, OR a region which is interpreted to have a high potential for the existence of extant martian life forms.

Given current understanding, this is to apply to regions where liquid water is present or may occur. Specific examples include but are not limited to:

• Subsurface access in an area and to a depth where the presence of liquid water is probable

• Penetrations into the polar caps • Areas of hydrothermal activity.”

Of course, it is the very regions that could support life that mankind is most curious about, and where the next series of martian lander missions will be targeted. So it will be expected that more stringent (IVc) requirements will be placed on future missions than were placed on Beagle 2, although many of the approaches for controlled environment assembly learned from the Beagle 2 experience can be applied to such missions. Note however that Beagle 2, as designed and built, would NOT have been able to comply with IVc requirements, and system redesign would be required to ensure that it would. The principal problem would be that Beagle 2 was an “open” system, so that parts of the lander sterilised to Viking post-sterilisation levels were not isolatable from those at the pre-sterilisation levels. Any “Beagle 2 reflight” would require additional concepts to be

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developed – the spacecraft resources (mass, cost, schedule) would be affected, but not necessarily increased. Planetary protection requirements need to be factored into the design process at an early stage (pre-phase A?) on any proposed Mars lander to ensure compatibility between the design and the COSPAR requirements.

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3. REVIEW OF DEVELOPMENT OF THE BEAGLE 2 PLANETARY PROTECTION PLAN AND ITS

IMPLEMENTATION 3.1 PLANETARY PROTECTION PLAN AND THE DESIGN PROCESS The initial start point of the Planetary Protection for Beagle 2 was the early recognition by the consortium that some sort of bioload control would be necessary. The first formalisation of the requirement was the Beagle 2 Planetary Protection Plan. The following two excerpts (3.3.1 and 3.3.3) from the PPP highlight the stage which had been reached by the CDR in September 2000 (less than 3 years before launch):

“3.3.1 Summary of Requirements for Category IVa The implementation requirements for Category IV missions comprise the avoidance of non-nominal impact and bioload control. Here, non-nominal impact denotes both accidental impact by hardware not intended to directly contact the target planet and significant deviations from the plan by the other hardware systems. The total probability of any accidental impact by any hardware other than probe, lander, or orbiter modules must not exceed 10-4. A. Summary of Bioload Reduction Requirements for Category IVa A1. Category IVa missions, comprising landers and probes without life-detection

experiments must meet a bioload limit specified for exposed surfaces. Bioload control requirements include contamination control (minimum requirement = Class 100,000 clean rooms and attendant procedures), microbiological assays and maintenance of hardware cleanliness.

A2. Contamination control effectiveness must be monitored and demonstrated by

periodic assays. A3. These assays must also be employed to determine the hardware microbial

burden. A4. For a Category IVa mission – only if needed to meet the burden requirement

specifications, e.g. for a subsystem with a large surface area – the project must provide the facility and the means to accomplish a bioload reduction.

A5. The facility will be subject to certification and the means of sterilisation and/or

bioload reduction subject to approval and monitoring. A6. Dry heat is the approved sterilisation method, and specifications for its use are

provided in Section 5.3. A7. Alternative methods require a demonstration of effectiveness by the project

and the approval of the Beagle 2 PPM.

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A8. Following the terminal microbiological assay and any microbial reduction

procedure (as required), the project must demonstrate that the spacecraft (lander or probe) is adequately protected against recontamination. Whatever the means of protection, the project must provide demonstrated evidence that contamination requirements are not compromised following terminal treatment.

B. Summary of Organics Inventory Requirements for Category IVa B1. An organics inventory is required of the bulk organic constituents of all

launched hardware which is intended to directly contact the target planet or which might accidentally do so. Each flight program office is to provide for the collection and storage, for at least 20 years, of the following information and material.

B2. Parts lists, material lists, and other program documentation containing data

relevant to organic material identification, which are prepared by a flight project to specify and control the materials that are included in a vehicle destined for planetary landing.

B3. A 50g sample of each organic compound used in a planetary lander vehicle

that is present in total amounts exceeding 25kg. B4. The locations of landings and impact points of major components of space

vehicles on the planet surface. Location(s) are to be determined and defined as accurately as mission constraints permit.

B5. Estimates of the condition of each landed spacecraft, to assist in calculating

the spread of organic materials. C. Summary of Documentation Requirements for Category IVa C1. A Planetary Protection Implementation Plan which must detail the planned

approach to compliance with the implementation requirements (e.g., mission description, probability estimates, burden estimates, contamination control plan, assay plan, microbial reduction plan).

C2. A Pre-Launch Planetary Protection Report which must document the degree to

which all requirements have been met and must include the values of the microbial burden at launch and the organics inventory.

C3. A Post-Launch Planetary Protection Report which must update the Pre-

Launch Planetary Protection Report. C4. An End-of-Mission Report which must provide a complete report of

compliance and the final disposition of all launched hardware.” …

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“3.3.3 Mars Express Classification Implications for Beagle 2 The interface between Beagle 2 and the Mars Express orbiter will be a consideration when the two become integrated at the launch site. In addition, maintenance of the sterility of the external surfaces of Beagle 2 are to be considered during both integration and conveyance into the launch fairing. Collaboration between the Mars Express Planetary Protection personnel and Beagle 2 personnel is essential for the maintenance of planetary protection compliance between the two. Until such time Beagle 2 will be treated as a separate entity to Mars Express in terms of the planetary protection requirements. The Planetary Protection Implementation Plan (PPIP) will detail the requirements which will be imposed on Mars Express personnel when Mars Express Planetary Protection Plan is released (MEX-MMT-PL-0247).”

In the context of this document, these requirements are self-explanatory. However, much of this initial information was developed without direct reference to the ongoing engineering design activity, particularly at the detailed level. Also included in the Beagle2 PPP were the “potential problem areas” for the adopted approach, although specific solutions were not necessarily available, even though the engineering design effort was proceeding with significant momentum. At this stage in the program, the philosophy was very much design it first and worry about the sterilisation later. In the case of the Beagle2 mission this was a recoverable position due to the small overall size of the lander. However, in the context of a larger mission, this would potentially lead to a lander design which would not be able to be assembled to meet the COSPAR requirements. The unresolved problem areas (and final solutions) are shown in Table 3.1: Table 3.1: Beagle 2 Sterilisation Challenges as Highlighted in the PPP Hardware Item (i) Challenge identified,

(ii) PPP proposed solution (iii) Evolution of solution by time of PPIP

Report

Thermal Insulation (i) Risk of shedding of organic debris from foams (ii) Seal in Kapton foil and use UV to reduce

microbial bioload. (iii) Seal in Kapton vented with Tyvek, bake to

sterilise throughout (UV unsuitable as effective in line of sight only)

Batteries (i) Not suitable for heat sterilisation

(ii) Wipe with alcohol wipes (iii) Sterilise by hydrogen peroxide gas plasma to

give better sterility assurance

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Solar Array Units (i) Phase Change Material (PCM) in deployment

mechanism not suitable for heat sterilisation. (ii) None proposed (dependant on type of material

to be used) (iii) Frangibolt mechanisms to be alcohol wiped

Parachutes (i) Sterilise/packing sequence conflict risk of debris ingress on deployment

(ii) Bake to reduce outgassing. Pack and rebake or use gamma radiation (Effect on material strength?)

(iii) Pack “clean” and bake. Debris ingress prevented by airbag material

Airbags (i) Sterilise/packing sequence conflict risk of

debris ingress on deployment (ii) Bake to reduce outgassing. Pack and rebake or

use gamma radiation (Effect on material strength?) Ensure insides are sterilised due to exposure on deflation. Material degradation?

(iii) Pack “clean” and bake. Debris ingress reduced by nature of airbag material. Small (tolerated) risk of fibres being present around the lander, overcome by modification to scientific method.

EDLS/structure (i) Maintenance of sterility after assembly

(ii) Use bioseal and HEPA filter on the vent (iii) As (ii)

Front shield (i) Presence of organisms on the external surfaces (ii) Bake to reduce bioload (is there a high

temperature bake during manufacturing that will reduce the internal bioload?) Maintenance through AIV and launch?

(iii) Sterilise by dry heat, rely on heating during atmospheric entry to maintain external sterility (>500ºC predicted)

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Back cover (i) Presence of organisms on the external surfaces

(ii) Bake to reduce bioload (is there a high temperature bake during manufacturing that will reduce the internal bioload?) Maintenance through AIV and launch?

(iii) Sterilise by dry heat, rely on heating during atmospheric entry to maintain external sterility (>500ºC predicted for some areas, >200ºC for all areas, subsequently modelled to demonstrate sterility - see Beagle 2 PP Pre-launch Report)

Solar panels (i) Large, delicate surface areas.

(ii) Use sterile alcohol wipes (iii) Requirement for no surface contact, since

coatings sensitive to solvent and abrasion. Dry heat sterilisation acceptable. Post-sterilisation, contamination prevention was the key. Witness plates used for contamination monitoring.

Pyro devices (i) Not suitable for heat sterilisation (ii) Wipe with alcohol wipes (iii) as (ii)

Science Instruments (i) Will they withstand baking? (ii) (not proposed) (iii) Sterilise by dry heat, or hydrogen peroxide gas

plasma where not compatible with heat

Mole, Arm (i) Internal and external require sterilisation. (ii) (not proposed) (iii) Sterilise by dry heat

Harness (i) Will require baking to reduce bioload (ii) (not proposed) (iii) Sterilise by dry heat, or hydrogen peroxide gas

plasma where associated with instruments not compatible with heat. NB all wiring specified as Raychem 55 radiation hardened, which gives sterilisation of effect on any embedded organisms.

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Mössbauer source (i) Due to the half life of the radioactive source

for the Mössbauer spectrometer the source will be inserted at last minute prior to delivery to the launch site.

(ii) (not proposed) (iii) Mössbauer source fitted as late as possible

prior to closure (decay tolerated)

X-ray Fluorescence Spectrometer source

(i) Due to the half life of the radioactive source for the XRS the source will be inserted at last minute prior to delivery to the launch site.

(ii) (not proposed) (iii) XRS source fitted as late as possible prior to

closure (decay tolerated)

By the time of the AIV activity, the unresolved issues from the PPP had all been addressed and the outstanding issues were limited to those which had arisen subsequently, namely: Thermal Insulation Foams (risk of shedding into the lander): Solution: seal in Kapton

vented with Tyvek (confirmation that this solution would be able to sustain launch evacuation was obtained by testing).

Back Cover A change in adhesive specification meant that it was not possible to

dry-heat sterilise this as a sub-assembly: aseptic manufacture of sub-assembly was performed to control/minimise contamination to a level acceptable to the PPM and this was accounted in the bioburden.

Main Parachute A change in design and materials meant that the baseline strategy of

dry heat sterilisation was not possible. Gamma irradiation at 25kGy was performed as an alternative.

3.2 INTEGRATION AND ITERATION OF PLANETARY PROTECTION ACTIVITY AND THE DESIGN PROCESS To reach the end point described in 3.1 above, significant involvement of the planetary protection function in system level and detailed design activity was required. In the context of the Beagle 2 project, much of the system design was already configured by the time that the detail of planetary protection was addressed. Thus planetary protection had to be implemented within the mass, budget and schedule constraints already imposed on the project. Whilst it is impracticable for unlimited resources to be made available to accommodate PP requirements (the mission would then be cancelled on cost grounds), some flexing can minimise/eliminate risk of PP requirement failure to the project. Examples from the Beagle 2 project are as follows: 3.2.1 Design maturity (schedule) constraints By the time of the CDR, the battery was essentially a fixed configuration item (size, mass, power requirement, location), requiring early integration of this as an item into the lander.

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Once installed, the lander could not be heat sterilised, as the battery would not withstand dry heat sterilisation temperatures. This limited the options for sterilisation of high level assemblies of the lander, requiring a substantial amount of the integration activity for sub-assemblies to be done post-sterilisation. It also limited the ability of the project to recover from any accidental catastrophic contamination of the lander within the build schedule. Earlier involvement of the PP function would have ensured the system design was altered to allow late integration of the battery into the assembly, allowing a simpler AIT task and lower PP risk within the project. 3.2.2 Mass-related constraints To stay within the mass limits, mass was saved by the use of soldering rather than connectors. In the context of doing rework of soldered ICs in a cleanroom, this proved to be false economy, both in schedule and PP terms. For the small amount of mass saved, the penalty was excessive, and in hindsight there were easier targets which could have been used to reduce/control mass. 3.2.3 Materials issues Individual components can determine whether or not a sub-assembly can be processed by a particular sterilisation method. Changing an individual item from standard off-the-shelf to MIL spec. can often mean that an electronic component is then specified as being able to withstand dry heat sterilisation. This can be as simple as changing the polymer used for a chip carrier from a low-melt to high-melt plastic. This is particularly the case when elements of the spacecraft/payload predate the mission design or are provided as “off the shelf” instruments. Another experience is that it is worthwhile developing the DML early to trap any non-obvious PP issues before the design is fixed. Examples include: the blocking talc for the parachute; any lubricants, coatings and finishes; adhesives and adhesive tapes. 3.2.4 Integration of Sterilisation Processes with Engineering Requirements It is also important for the design and engineering staff to understand fully the steps and procedures involved in sterilisation processing. The protocols described in Appendix 1 and 2 were developed for the Beagle 2 team and, with design team input, were tailored to meet specific hardware needs. As an example, hydrogen peroxide gas plasma sterilisation is performed in a shallow vacuum in an environment heated to 45ºC. However, the battery to be sterilised by this process is irreversibly degraded at this temperature. Tests were performed to look at the thermal inertia of the battery to ensure that it did not heat up to beyond 35ºC during the time duration of the sterilisation process. As an additional step, knowing that the lower temperature might compromise the sterilisation efficacy, biological indicators were used to ensure that the process had achieved the degree of sterilisation claimed in the PP documentation. In summary, for smooth implementation of PP it is important to ensure that iterations of the design and PP implementation proceed in an integrated fashion, such that changes in design are assessed for their impact on planetary protection and vice versa. 3.3 NON-TECHNICAL ISSUES AND IMPLEMENTATION OF PLANETARY PROTECTION

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In a complex work environment such as an ESA space mission, with its many internal and external organisational/political constraints and interrelationships, early communication of PP expectations is important in PP implementation. The following are examples from the Beagle 2 project which will allow future missions to learn from our experiences rather than re-enacting them. 3.3.1 Documentation The classification of Beagle 2 as a “science instrument” to be delivered to the Mars Express mission meant that some of the usual ESA requirements from a full Spacecraft status mission were relaxed. In particular, the ESA document control structure was not rigorously enforced on the Beagle 2 Planetary Protection function, beyond providing sound evidence that the information and claims within the COSPAR-published Planetary Protection documents could be justified. The PP document system is therefore not fully evolved and indeed, if the Beagle 2 project had this as a requirement, it would not have been able to meet it within the timescale and resource constraints of the mission. However, the expectation should be that for future ESA Mars missions in particular, this will be a mission requirement. 3.3.2 Cost issues Leaving aside the direct cost of the AAF operation, the cost of implementation of PP in the Beagle 2 project was not insignificant. This included modifications of suppliers’ facilities and working practices to meet cleanliness requirements, off-site working in the AAF, and production of bespoke versions of standard equipment to operate at the required cleanliness level. This needs to be borne in mind by all parties when inviting and assessing quotations, and the structure of contracts. 3.3.3 Access to Information Planetary Protection implementation requires the relevant PP authority to have in-depth knowledge (potentially at the molecular composition level) of the spacecraft materials. The project needs to ensure that the necessary permissions and authorisations are in place in a timely manner to allow the appropriate level of access to information in order that the PP function can influence the design at an early enough phase in the programme. This particularly applies in the case of international partners where technology transfer is restricted, or in the case where supplier organisations may want to protect in house IPR. 3.3.4 Post-assembly Planetary Protection Since PP responsibility is until launch, it is required that PP oversight is maintained until launch. In the case of Beagle 2, the PP function had little or no visibility or influence on the detail of the planned handling of Beagle 2 during the launch campaign until it actually happened. It was accepted that the Mars Express team would maintain the necessary Class 100,000 cleanliness levels, but there was no formal feedback route for this to be confirmed. Ad hoc reporting from members of the MEx team did allow the Beagle 2 PPM to convince the relevant national authorities that the Beagle 2 project had remained within the COSPAR requirements for the mission category. To minimise PP risk to future missions, the PP function of the mission should have a detailed understanding, and be involved in the preparation, of the stages beyond spacecraft completion up to and including launch, from an early planning stage.

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4. REVIEW OF DESIGN AND CONSTRUCTION OF THE BEAGLE 2 ASEPTIC ASSEMBLY FACILITY

4.1 FACILITY SITE SELECTION Once the requirement for an aseptic assembly method was determined, the search for a suitable facility was undertaken. Initially, the availability of pre-existing facilities was investigated. Within the aerospace industry, none were readily identified at the correct cleanliness level or configuration. Within related industries, a Class 1000 (US Fed Std 209E) facility was identified local to the prime contractor (<30km from EADS-Astrium, Stevenage), which could be made available. However site safety (no explosives licence, no experience of aerospace manufacturing) and access (controlled site operating fixed hours) meant that operating out of this site would have been a significant schedule risk to the project. Sites suitable for conversion to custom cleanroom facilities were then considered (green-field development was not considered because of cost and time issues). Sites remote to the main sites for the consortium were discounted because of infrastructure and security issues. A site within the main EADS Astrium complex was considered, but local management could not guarantee availability of the area for the duration of the Beagle 2 project. The site finally chosen was a vehicle garage with 7m ceiling and adjacent warehouse facility within The Open University campus in Milton Keynes. Physically it was able to accommodate an aseptic assembly facility of this type, with supporting local infrastructure (IT, site access control, catering, workshops etc), on the campus of a Beagle 2 consortium member, with unfettered work access plus an OU undertaking to make the site available for the duration of the project* meant this was the best option. Risks associated with this option were the ability of the OU to manage the conversion to a cleanroom in the time and budget* available, and the fact that this would be an unproven facility outside the direct management control of the prime contractor. 4.2 FACILITY DESIGN AND SPECIFICATION Fundamental to the design process of the cleanroom is the in-built size conflict: Aerospace facilities tend to be large, to allow lots of separation between items, facilitating working access and allowing significant margin for movement of items in and out of the area and minimising the risk of collision damage occurring to expensive hardware. Conversely, clean areas tend to be as small as possible, minimising the “spare” space (which all has to be kept clean), and reducing the volume of air which is required to achieve a given class of cleanroom performance (and therefore the overall cost of the facility). In the case of the Beagle 2 facility, the available budget and the stringent cleanliness requirements, together with the physical constraints of the site, meant that the final design for the facility was smaller than that which was considered optimum by EADS-Astrium. However, it was configured so that all tasks associated with the build activity for Beagle 2 could be performed in the space available (see Figures 4.1i and 4.1ii).

* In return for ESA budgetary input, the OU signed a contract not only to make site and facility available for the duration of the project, but for a further five years for any ESA sponsored project.

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Figure 4.1: Beagle 2 Cleanroom Layout

i) Room configuration and cleanliness regime

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ii) Operational concept

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The specification document used for the tendering process (required under European legislation) is given in Appendix 3. Although the layout is unchanged, there are several modifications in the as-built design. Most significant is the provision of a fully ULPA-filtered ceiling in the ISO Class 4 (Fed 209E Class 10 – see Table 4.1 below) area, giving vertical laminar flow with airflow return via a raised floor in the cleanest area. This gives two major benefits; first the cleanroom has a greater airflow (circa 4x tender specification), and therefore recovers more rapidly from contamination events, and second, there is no restriction within the cleanroom as to what activities can take place in what zone – all zones are equally clean. One other major issue which affected the design and specification of the cleanroom was the different operational requirements for the facility imposed by the different activities associated with the Beagle 2 build. Normally, a cleanroom area is designed to meet a given particulate, sterility or chemical cleanliness criterion for a specific industry. In the case of Beagle 2, all three criteria were required, and in a cross-disciplinary application. Hence ESD control requirements were imposed from the aerospace side. This is not normally a requirement for medical/pharmaceutical cleanrooms. By contrast, plastic/carbon containing items with off-gassing potential were eliminated as a science requirement. Specific lessons learnt from this exercise are given below: 1) In consultation with the Beagle 2 prime contractor, Static Dissipative flooring was selected for the AAF. What was not fully appreciated was the tendency of the high volume airflow in the aseptic assembly area of the AAF to generate static. Whilst a conductive flooring solution would have been better able to cope with this effect, this type of (typically carbon-loaded) flooring would conflict with the particulate/carbon control requirements of the project. A better solution would have been to include a suite of ionisers in the cleanroom airflow. 2) HEPA/ULPA filter frames commonly use a semi-solid paraffin compound as a seal to the filter unit. Over time (approx. 20 years) this material evaporates. With total loss cleanrooms, using few filters with low airflow volumes, this is insignificant. However, with over 50 filters, this translates to 50kg of paraffin, and with air recycling up to 20 times (5% fresh air make-up) this translates to a significant paraffin presence and a risk to the GAP experiment. The Beagle 2 project therefore adopted the “old” neoprene gasket technology for this application.

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Table 4.1: Cleanroom categorisation

ISO Maximum concentration limits (particles/m³ of air) for particles equal to and larger than the considered US FED BS5295 European

Classification sizes is shown tabulated below 209 E GMP

number (N) NB Blue figures relate to particles (ft³) and superseded (or existing) Standards/Guides (operational)

0.1 µm 0.2µm 0.3µm 0.5µm 1µm 5µm

ISO Class 1 10 0.3 2 0.06

ISO Class 2 100 2.8 24 0.07 10 0.3 4 0.1

ISO Class 3 1 000 28 237 6.7 102 2.9 35 1 8 0.22 0 M1.5 1 C

ISO Class 4 10 000 284 2 370 67.3 1 020 28.9 352 10 83 2.3 0 M2.5 10 D

ISO Class 5 100 000 2841 23 700 673 10 200 289 3 520 100 832 23.6 29 0.8 M3.5 100 E/F A (B*)

ISO Class 6 1 000 000 28410 237 000 6732 102 000 2897 35 200 1000 8 320 236 293 8.3 M4.5 1 000 G/H

ISO Class 7 352 000 10000 83 200 2363 2 930 83 M5.5 10 000 J B (C*)

ISO Class 8 3 520 000 1E+05 832 000 23630 29 300 832 M6.5 100 000 K C D

ISO Class 9 35 200 000 1E+06 8 320 000 236300 293 000 8323

Notes: Uncertainties related to the measurement process require that concentration data with no more than three significant figures be used in determining the classification level. * denotes “at rest” conditions

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4.3 BUILD SCHEDULE Due to the tight schedule between release of funds for this activity and the requirement for access to an operational AAF, the building of the cleanroom was a more compressed schedule than would have been usual: May 2001 ITTs issued Jul 2001 Tenders reviewed and preferred contractor selected Aug 2001 Building work commences Dec 2001 Practical completion of the cleanroom facility Mar 2002 Operational readiness of cleanroom facility Jul 2002 Cleanroom and Office fit-out completed Oct 2002 Commencement of aseptic assembly of Beagle 2 In the original build philosophy, first arrival of Beagle 2 elements for sterile assembly was to have been in April 2002. This would have been a struggle for the AAF project team at the OU to achieve. There were a number of issues which contributed to the delay until July, including:

• Late finalisation of specifications from Beagle 2 project on long lead items. • Replacement (ordering delay) of cleanroom items found to be unsuitable on delivery

(for example, standard Class 10 cleanroom chairs with over 20 plastic components and at least 3 different lubricants were rejected in favour of a simple stainless steel alternative).

• Commercial negotiations within the project continuing over who is responsible for which costs, cost overruns and change requests.

• Delays associated with on-site sub-contractors. 4.4 FIT-OUT AND COMMISSIONING ACTIVITIES The cleanroom was commissioned prior to practical completion at the site by the cleanroom construction company (Bassaire). However, before commencing Beagle 2 assembly operations, a second validation was performed by an independent company, confirming the status and performance of the facility. The fitting out included furniture, cleanroom monitoring equipment, communications & IT equipment, instruments, tooling (standard tool kits were provided to EADS-Astrium specification), general MGSE and lifting gear, Beagle 2-specific MGSE (sourced by EADS-Astrium), sterilisation and cleaning equipment, spin balance instrumentation. It would have been advantageous to fit and test EGSE equipment at this stage, however due to the cost and time constraints the project was under, a duplicate set was not available. This meant that EGSE set up and test was subsequently on the critical path for lander assembly. The cleanroom particulate monitoring system comprised a Pacific Scientific 2400 particle counter unit, with 0.3, 0.5, 1.0, 5.0 and 10µm detector settings, linked to a manifold sampling from fixed points within the AAF to a set schedule. The system, together with proprietary building management software, QSCADA, was fitted by Facility Monitoring Systems Ltd.

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FMS also integrated signals from the temperature, humidity and pressure monitoring into the QSCADA system. A second Pacific Scientific unit was retained as a back-up (since the cleanroom cannot be operated without particulate monitoring). This unit was also used for local monitoring of activities in the cleanroom remote to the fixed monitoring points. To do this, an instrument isolator was built, with direct venting outside the cleanroom to allow the counter (pump, cooling fan and all) to be in the cleanroom without compromising the cleanliness. The PA-validation of certain items is affected by disassembly/cleaning operations necessary to introduce them into the cleanroom. It is therefore worth considering at an early stage the sequence for commissioning a specific item for operation in a cleanroom area. Examples from the Beagle 2 experience include the following: 1) Spin balance machine: specialist set-up and calibration by the manufacturer was required. Training in cleanroom working and procedures was undertaken for these staff to allow calibration to take place in the clean area after cleaning of the instrument (NB instrument had additional cleanroom casing with own extract to protect the cleanroom). These staff were 100% monitored by experienced cleanroom operatives. 2) Quickset Torque wrenches: calibrated meters for setting the torque wrenches were permitted in the support areas of the cleanroom. Tools calibrated before each use, following sterilisation. 3) Crimp tools: it was discovered that cleaning crimp tools removed lubrication, changing the performance and therefore negating the validation. The only solution was to encapsulate the working mechanism of the tool in sterile wrapping, only allowing the crimp head to contact the workpiece. 4) Adhesive preparation: typically mixing/preparation of multipart adhesive mixes is a QA monitored activity. As an operating requirement, mixing of adhesives was introduced very late into the AAF operating systems, and a process had to be rapidly developed and introduced. Ideally a system would be in place to allow controlled mixing to agreed recipes whilst maintaining the sterility/cleanliness of the adhesive used on the spacecraft (or if the spacecraft is terminally sterilised, this extra process is not required). On the larger MGSE items, paint was discouraged due to offgassing concerns, risk of chipping (and effect on science) and concerns about repeated exposure to IPA cleaning. Two preferred options were identified: Stainless steel (316 grade, satin finish) or (and more cost effective in most cases) Alochrom-coated aluminium. Dip coating was the preferred method as brush application of Alochrom was too uneven to be easily cleaned within the clean area. Uncoated aluminium was not permitted because of the particles of aluminium oxide generated during cleaning. Note that 308 grade stainless material was found not to be acceptable for use in the facility. One area of validation which was comparatively neglected was the ESD compatibility of the fitted-out environment, and the various work processes in the cleanroom. It was considered to be sufficient that fittings were all specified to be ESD compatible and all grounding paths were identified and connected. However the facility was not tested or monitored before commencing assembly operations. This meant that significant numbers of teething problems with operating in the facility associated with ESD control were identified whilst flight hardware assembly was taking place. These included:

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• Loose connection on ESD grounding path • Unreliable grounding paths through some cleanroom garment sets • Wrapping of (“dirty”) test cables with Steriking film (to allow entry into the cleanroom)

leads to significant static charge generation. In the case of the garment sets, significant effort was expended to ensure grounding was maintained, by using additional disposable overshoes with “in sock” conductors, redundant anti-static wrist straps, and floor plates. Such “belt and braces” approaches will have improved performance, but thorough testing of the system before commencing operations would have given a greater degree of confidence. In the case of the wrapping, the solution was to use Richmond conductive (grey) bagging material as an alternative, which prevented static build up. This was shown to work quite satisfactorily.

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5. REVIEW OF OPERATION OF THE BEAGLE 2 ASEPTIC ASSEMBLY FACILITY

As previously highlighted, the PP requirements for the Beagle 2 spacecraft were to mission category IVa, with additional cleanliness driven by the science requirements of the mission. Within the AAF, this was used to drive a set of protocols and working practices to minimise the risk of accidental contamination of the spacecraft. 5.1 ACCESS Permission to work was only given after an individual had received training; first, on planetary protection, and second, in AAF working. The PP training was nominally a 2 day course, developed by the PPM in conjunction with industrial and academic experts as shown in Appendix 4. For some visiting workers performing low-risk, short duration tasks, this material was condensed, however these individuals were then supervised much more closely than individuals who had had the full training. Training in AAF working was based on the document shown in Appendix 5, though usually delivered by coaching rather than as a classroom exercise. All individuals had medical pre-screening to establish that they did not have medical conditions which would compromise the cleanroom/spacecraft hardware. Key targets are chronic bacterial or fungal conditions that cause excessive shedding of skin scales in affected individuals. In taking expert advice, we were told to expect 1/60-1/200 individuals in the population to be medically unsuitable for cleanroom work. In addition, special constraints were placed on smokers, and individuals who were ill were not permitted to work if their condition resulted in either excessive particulate generation in the cleanroom, or an inability to work in cleanroom garments. Beards, moustaches, sideburns and “designer stubble” were not permitted in the cleanroom due to their compromising the sealing of the standard facemask against the face. Several individuals were required to remove facial hair in order to remain on the team. Only on one occasion was it necessary to instruct someone to shave before entering the cleanroom. 5.2 MANNING LEVELS Manning was unrestricted in the outer (Class 1,000 & 100,000) areas. However in the Class 10 (ISO Class 4) Aseptic Assembly Area, numbers were limited to four at any one time. The reason for this was two-fold: first it was unclear on what number of individuals the room would support before becoming degraded. Second, all the individuals’ activities were monitored and supported from outside the clean area and this would have been very much more difficult if a larger number of workers had been present (the number of monitoring staff, IT interfaces and voice communications interfaces would all have had to be increased). The potential confusion arising from this would have compromised control of planetary protection. As greater numbers are present, there would have been more risk of accidental damage due to the space limitations of the room. Also the service infrastructure of the cleanroom (in terms of garment supply, tools and so on) was geared towards four people working in the Class 10 area, and would have become untenable.

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5.3 CLEANLINESS SPECIFICATION It was considered that the Aseptic Assembly Area could operate manned at a cleanliness level of up to and including Class 100. This was easily achieved for most operations. However, certain activities, principally soldering and heat shrinking, sent the particle count off-scale (>106). This was not a problem, since the excursion event was always tied to an identifiable activity, precautions could be taken to prevent contamination of critical items, the cleanroom recovered rapidly (usually within 5 minutes at the individual workstation), and there is no microbiological contamination risk with either of these operations. These, and other operations where particulate contamination was known to be a risk, were locally monitored within the cleanroom, using the portable particle counter as well as the fixed facility monitoring points. Direct observation was used to ensure that these “dirty” operations did not mask biological contamination events. 5.4 MONITORING Although covered in Section 6 in more detail below, it is worth noting the monitoring capabilities used within the AAF.

• Microbial • Particulate • Environmental (Temperature, Relative humidity, Differential pressures) • Visual (camera and observer) • ElectroStatic Discharge protection • Chemical

Of these, microbial monitoring is solely a PP role; particulate, environmental and visual have joint PP/Spacecraft PA functions, ESD protection is a spacecraft PA requirement, and chemical monitoring is a science payload requirement. 5.5 MATERIALS CONTROL One of the key scientific drivers for the Beagle 2 team was to control and characterise the organic materials to which the Beagle 2 spacecraft was exposed. Some high risk materials were banned or restricted within the cleanroom, and of the “permitted” organic materials, all were identified, had samples taken, and were analysed by a terrestrial-laboratory equivalent of the Beagle 2 GAP. Of the banned items, paper is the most significant in terms of the spacecraft build process: all papers (including cleanroom types) are fibrous, friable and organic. Generally speaking they are brought into the cleanroom from non-sterile external environments as reference documents. This could not be permitted whilst having any hope of retaining the integrity of the aseptic build philosophy, and was acknowledged early in the AAF design. The solution was to provide 3 x 42” plasma screens facing into the Assembly Area from the Test Equipment Room (one per PC workstation) with mouse and keyboard inside the cleanroom, allowing electronic access to documents and electronic checking off of activities (see Communications below), but a paper-less cleanroom. The plasma screen solution was augmented by making the entire wall of the test equipment room (which was also the

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observation area for PP monitoring) out of glass. In this way a two-way discussions between people inside and outside the cleanroom can be held with hand written amendments to drawings held up against the glass. This constraint also meant that labelling had to be other than with paper (also applies to the spacecraft parts). This was using Brady labels (part no.NAED~62272 – a high temperature type to permit sterilisation). The desire to minimise the number and amount of different organic materials in the cleanroom environment meant the standardisation of equipment and consumables wherever possible. Sterilisation packaging was Tyvek for items to 120°C (spacecraft hardware, tools, MGSE and consumables) and Steriking (180°C-rated) for high temperature tool sterilisations. Steriking packaging was also used for sleeving non-sterilisable items used in the cleanroom (eg EGSE cables, crimp tools), however when it was subsequently discovered that these generated a static problem, this was switched to Richmond conductive (grey, not pink) anti-static bagging. The initial intention to standardise to a single sterilisation packaging was not achievable, which meant that training and process control methods were required to ensure mistakes were not made between different packaging and sterilisation processes. The tooling provided within the facility was also subject to restrictions on organic materials: pliers and cutters had soft plastic handles removed, metal-handled scalpels with separate blades were used in preference to disposable types, breakback torque wrenches had organic lubricants (grease) removed and were WS2 (dry lubricant) coated. The dry lubricant coating process adopted was found to be resistant to IPA cleaning and dry heat sterilisation, which was extremely beneficial to the project. Cleaning solutions were another controlled item. The Beagle 2 project agreed on the use of 70% solution of IPA (Iso-propyl alcohol) in sterile water as standard cleaning agent. IPA was preferred to ethanol as it does have a limited sporicidal activity, whereas ethanol does not. Commercially available cleaning agents commonly used in cleanroom environments containing surfactants or ions were not used because of the risk of residues compromising either the spacecraft performance or the organic detection of the Gas Analysis Package. 5.6 CLEANROOM COMMUNICATIONS Voice communication with staff inside the cleanroom was facilitated by a microphone and speaker system custom designed to be compatible with cleanroom operation, with connection from the test equipment room to all other areas of the AAF. Patch-in of telephone was available to allow staff in the cleanroom to hold conversations with remote sites. The system was a hard-wired single channel system and proved to be limiting in several respects:

i) Airflow noise in the aseptic assembly area and background noise in the test equipment room compromised the quality of the sound. Whilst normal working was not hampered as such, there was certainly room for improvement.

ii) The cleanroom garments themselves hampered communication – ears were covered by the hood and mouths by the mask

iii) There were occasions when multiple channels would have been advantageous.

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RF based comms. systems were excluded at the cleanroom design stage because of concerns of effects on the spacecraft hardware. If this constraint were relaxed, then RF boom microphones and earpieces could be considered for wearing underneath the cleanroom garments, being suitably cleaned in between shifts (cf safety glasses - IPA wiped after every use). Alternatively, more use could be made of standard telephony systems, although key to the efficient cleanroom operation was the capability to protect the workers in the cleanroom from disruptive calls by routing everything through the Test Equipment Room. 5.7 IT INTERFACE The IT interface into the cleanroom was via 42” plasma screens with operations in the cleanroom performed via gas plasma-sterilised keyboard and touchpad devices. These were connected to high end PCs on the OU network and thence to the outside world. The advantage with a touchpad compared to a mouse is that it has no moving parts or cracks which make cleaning difficult. However, they were less precise in operation than a mouse, particularly when wearing gloves. Wired technology was used, which constrained the mobility of the system in the cleanroom. Again, if wireless technology was permitted (RF rather than IR), this situation would be improved. Also, the 42” plasma screens could be replaced by twin flat screens at the cleanroom workstation (at the time of cleanroom build, small flat screens of the correct resolution were not easily available, CRT monitors were deemed too dirty/bulky for cleanroom use). The IT system of work was not sufficiently well defined before working in the cleanroom was required to start. There were major security issues between the two principal organisations (the OU and EADS-Astrium). These could have been fully addressed by a £200k upgrade of the EADS-Astrium system, for which there was no budget or time to implement. The partial solution was a standalone EADS-Astrium server at the OU with data transfer back to the EADS-Astrium main system. Data sharing between the EADS-Astrium system and the AAF PCs was by ftp protocols. However, software licensing and data security continued to be problematic, particularly for EADS-Astrium staff, hampering the rapid transfer of electronic documents. 5.8 KITTING/STOCK CONTROL The magnitude of this issue was underestimated by all parties. The anticipation was that kits of parts would arrive, be sterilised as kits, or at least at the same time, then be passed into the cleanroom as kits, or after short term storage in the Final Prep area of the AAF. What was not appreciated by the OU team was the number of “kits” which were involved (so no storage/inventory system was provided beyond open shelving) or the amount of fabrication of items which would be required post-sterilisation. What was not appreciated by the EADS-Astrium team was the difficulty of tracking anonymous white packages (which all sterilised items became) as the number and complexity of kits increased. The solution is to provide more labelled storage in the Final Prep area (minimising the amount of material in the Aseptic Assembly area whilst maintaining good stock control).

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On the positive side, a policy of sterilising extra quantities of small items, such as fixings, to allow for losses due to dropping or other potential contamination events paid dividends in allowing AIT tasks to continue without having to wait for resterilisation to take place. 5.9 REHEARSALS Two of the features of the Beagle 2 programme were i) the paucity of pre-flight models, flight spares etc. and ii) the “just in time” nature of the availability of parts, assemblies etc. for final assembly. It was therefore difficult to perform all the necessary fit check and assembly rehearsal tests off-line, in a less stringent environment than the AAF. This predictably led to some challenges in terms of assembling sterilised items aseptically. In particular, cut-to-fit operations for 3-d structures (eg foam) should be avoided and for 2-d structures (eg thermal control elements such as metallised kapton sheet) should be minimised. Also, harnessing runs fabricated pre-sterilisation would have been much less difficult than fabricating harness/installing tie-downs in situ in the cleanroom. Initially, many of the team members were unused to working in cleanroom coveralls, gloves and masks (usual aerospace class 100,000 gown and mob hat was most peoples’ experience). This meant a decrease in efficiency until staff had become accustomed to working in the new garments. Further to this, some individuals have unusual garment size requirements and need to be specially catered for (6 week lead time for garment manufacture). Trial fitting and task rehearsal therefore are important schedule time savers in the context of aseptic assembly of spacecraft. 5.10 AUTHORITY AND MANAGEMENT INTERFACE The current reporting of Planetary Protection is via a national “corresponding body” into COSPAR, operating under the requirements of the 1967 “Outer Space Treaty”. In practical terms the UK’s corresponding body, The Royal Society, established a Sub-committee of independent experts to monitor and approve the PP activity for Beagle 2. Further, there was a requirement to satisfy the customer (ESA), and the launch vehicle authority (launching nation, jointly Russia and Kazakhstan) that PP standards had been met, as shown in Figure 5.1. In this regard, Beagle 2 PP had significant visibility within the project, and as a Fly/No Fly issue, PP matters carried a significant level of authority in the project during the build phase of Beagle 2. However, at the extreme, the authority of the Planetary Protection manager and reporting line was not tested: Operationally, there was an absence of gross contamination of Beagle 2 during the build phase, and the pragmatic resolution of conflicts between AIT and PP activities on a day-to-day basis were achieved without compromising the Planetary Protection status of the spacecraft.

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Figure 5.1: Beagle 2 Organisational Structure as pertaining to Planetary Protection & AIT

Supra-national bodies

ESA (customer) COSPAR (regulator)

National bodies

Russian/Kazakh launch authorities

Royal Society Planetary

Protection Sub-committee

(Corresponding National Body)

Beagle 2 Consortium Board

Astrium Snr

Mgmt (Prime Contractor)

OU Snr Mgmt

Project Manager Lead Scientist

AIT Manager Other Beagle2

Subcontractors PPManager/AAF

Manager

AIT Team AAF Team

What was not developed during the Beagle 2 project was a formal “waiver” system for deviations from nominal on planetary protection issues (compared to design/engineering activities). The informal system (planetary protection manager open contact with members of the Royal Society subcommittee) lacks the rigour which might be expected on an issue which has Fly/No Fly responsibility. As a note, since the launch of Beagle 2, the Royal Society has transferred the interface with COSPAR concerning Planetary Protection to the Rutherford Appleton Laboratory (RAL). This was justified on the basis of the subject being more closely aligned to the activities of RAL. However, a number of issues now arise for RAL concerning conflict of interest, both in competition for projects and in management of ongoing projects with interplanetary spacecraft. 5.11 TYPICAL DAILY OPERATIONS/ DETAILED PROTOCOLS

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Ahead of daily working, tool kits of sterilised, wrapped tools required for the planned activity would be prepared in covered stainless steel trays. Necessary drawings would be made available either electronically or in paper form for viewing through the viewing window. Pre-sterilised spacecraft hardware would already be stored in the Aseptic Assembly Area ready for integration. 5.11.1 Entry into the cleanroom All personnel entries into the cleanroom were logged. The purpose was two-fold:

i) To identify individuals responsible for excursions of particulate levels out of the permitted range, either for retraining (to prevent recurrence) or for exclusion (in the event of excursions due to illness/skin conditions).

ii) To allow the video record (see 6.1.3) of activities to be matched to individuals (people in full body suits with masks and glasses on all look very similar).

The entry log was also used for management information on the use of the cleanroom. Whilst useful for highlighting efficient use of the facility, care was taken to ensure that it was not used in such a way that staff were discouraged from filling it in (it was never permitted to be used as a “timesheet”). 5.11.2 Garments and Gowning A standard gowning procedure was adopted by all staff working in the clean area, as per the gowning protocol (included in Appendix 5). This evolved slightly during the build programme (as discussed elsewhere, off-line rehearsal of activities may have led to earlier adoption of the optimised protocol). Rental garments were custom manufactured for ESD and sterilisation compatibility. The selected garment regime was sterilised class 10 laundered hood, sterilised class 10 laundered coverall and class 10 laundered boots (the sterilisation process was not compatible with the ESD boots, but since the boots were always below the level of the hardware, with the airflow carrying material away, this was considered acceptable), over class 100,000 laundered cleanroom undergarments (top and trousers). Garment changes were 1 per session (outer hood, boots and coverall) and 1 per shift (day) for undergarments. 5.11.3 Working in the clean area Cleanroom working was always with reference to the cleanroom operator training and cleanroom work disciplines documents (Appendices 4 and 5 respectively). Session/shift times were 4hrs and 8hrs respectively, with operators typically taking one coffee break per session (allowing one reuse of outer cleanroom garments). Up to 4 workers were permitted in the Aseptic Assembly Area (cleanest area) at any one time. Continuity testing and glove cleaning was performed on entry, and periodically thereafter Care was taken in positioning workpiece, tools and operator to minimise contamination risk. The cleanroom operator was supported from the other areas, supplying sterile tools, componentry and information, to allow the operator to get on with the task in hand.

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As a rule of thumb, mechanical and electronic assembly tasks for an experienced cleanroom operator took 2-4 times longer than in a class 100,000 environment. This was substantially longer for inexperienced operators, and there were certain tasks which were immensely more difficult due to their fiddly nature and/or the need to protect the lander from contamination by reaching over the lander or involving lots of individuals in the task. Handover (between shifts) and PA activities were performed (in so far as was humanly possible) from outside the cleanroom. 5.11.4 Cleaning the clean areas A cleaning programme for the cleanroom rooms was drafted based on expected usage levels and cleanliness requirements for each area. Cleanroom cleaning was only done when AIT activities were not ongoing, usually at the end of each shift, both to minimise the risk of spacecraft contamination during cleaning activities and for Health and Safety reasons. Early operations in the AAF, together with the microbial monitoring programme, quickly highlighted “hot spots” in terms of microbial contamination control, and protocols were amended accordingly. Cleanroom support staff cleaned different areas on a per shift/per day/per other day/per week/per month basis as appropriate to the area being cleaned, and signed off that that area as having been cleaned. Occasionally, members of the spacecraft AIT team were asked to perform specific cleaning tasks in local areas if it was identified that there was a high risk that microbial contamination had occurred during AIT operations, rather than waiting until a scheduled clean. Examples of cleaning protocols are attached in Appendix 6. One of the lessons learnt in the course of this project was that vacuum cleaners fitted with brushed motors are only suitable for areas up to Class 1000. Dyson DC0XX Cylinder cleaners with HEPA filters were used in the Beagle 2 facility; one for intermediate change/final prep (Class 1000 areas) and another separate unit for initial change/primary prep (Class 100,000 areas). The Class 10 area did not accumulate levels of contamination on the floor, and in any case the vertical laminar flow carried material away through the floor vents – it was considered that, for the duration of the Beagle 2 build activity, the cleaning activity was more of a risk than the leaving the floor uncleaned. Gross contaminations (cable offcuts, solder splash, fragments of sterile packaging) were collected and removed however.

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6. REVIEW OF MONITORING OF THE BEAGLE 2 SPACECRAFT AND ASEPTIC ASSEMBLY FACILITY

With sterilisation of the hardware addressed, and the cleanroom performing to high standard, it was clear that the principal risk to Beagle 2 sterility status was the intensive exposure to the humans performing the assembly tasks. Monitoring was therefore performed to ensure the risk was minimised and that the microbial bioload status of the spacecraft was known at all times (within the limitation of the sampling methodology). Monitoring was also performed within the facility to verify other parameters were within the specification required for the spacecraft itself, and for the scientific integrity of the payload experiments. Alone of the monitoring approaches employed, only the microbial monitoring of the spacecraft hardware itself was formally reported. 6.1 MONITORING ACTIVITIES A summary list of the monitoring strategies is given in the following sections: 6.1.1 Particulate Particulate monitoring was to nominal cleanliness levels for each of the rooms in the AAF (see Chapter 4), was monitored continuously, and was on an alarm. Warning limits at the level of 50% of the room classification (ie 500 particles >0.5µm/cu.ft. in a class 1000 area), and action levels at the room classification (ie 1000 particles >0.5µm/cu.ft.` in a class 1000 area), were established. These were known to be acceptable and relevant by experience, in terms of the planned operations compared to the cleanroom performance. 6.1.2 Environmental (Temperature, Relative humidity, Differential pressures) Temperature was continuously monitored, but in terms of operator comfort only. Typically a working temperature of 16-18degC was requested by the (fully suited) operators in the Aseptic Assembly Area. Comfortable temperature is a major factor in the ability of workers to operate for longer periods in the cleanroom, and should not be overlooked in the design of any facility. Relative Humidity was monitored from a comfort point of view but also as a requirement of Health and Safety regulations for operating in an environment where explosives were present (RH below 30% has an increased risk of static). The setpoint for the Beagle 2 AAF was 50%, and was alarmed with warning limits at +5% and action limits +10%. Note that from the point of view of preventing microbial growth, it is desirable to keep the humidity as low as possible, however the health and safety consideration takes precedence. Differential pressures (relative to ambient) were continuously monitored to ensure a cascade from “inside” to “outside” was maintained. These were alarmed at setpoint+5Pa for >7secs. The most common alarm was for these to be activated as a result of a door being held open for a conversation to take place. This was actively discouraged, however better communication capability within the facility would have removed the necessity.

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6.1.3 Visual (camera and observer) A high level fixed pan/tilt/zoom camera, together with a hand-held portable unit, were used for PP monitoring and engineering tasks. Output from both was recorded and archived on a 24hr/7day basis to allow check-back of events and activities if required (which subsequently proved very useful in this respect). For example, the time stamp on the camera record allowed confirmation that the correct interval had elapsed between applying an adhesive primer and applying the adhesive itself. It was standard working practice that whenever anyone was working the class 10 Aseptic Assembly Area, a member of the planetary protection team would be observing from the Test Equipment Room. This was for enforcement (“you have just touched your mask – you need to wash your gloves”), advice (“yes, it’s OK to reuse that tool, since it hasn’t contacted a contaminated surface”) and general support (“I’ll call up to the design team on your behalf to have them come down and resolve this technical problem”). Although there is a ready made conflict in a non-engineer telling an engineer how they may or may not do their job, generally there was not an issue because of the training and appreciation of all the staff involved in Beagle 2 of the risk to the mission associated with biological contamination, and the professionalism of those involved.* That is not to say there were no occurrences where stressed individuals found themselves struggling with fiddly activities whilst further encumbered by cleanroom garments and protocols. In the final analysis, no activities were permitted which risked non-recoverable contamination of the lander/probe system, and microbial monitoring did not detect any. For future missions, the use of raised observation platforms would be useful to get a better view of the ongoing activities. Also, logging of the personnel present on the observation platform during activities would have provided proof positive that the PP monitoring task had been done.

6.1.4 Electrostatic Discharge (ESD) protection Wall mounted resistance test boxes were fitted in the Final Change are and in the Aseptic Assembly Area, for initial test and ongoing monitoring of the ESD performance of the garments during the work period. 6.1.5 Chemical Chemical monitoring was performed to measure total VOCs in the cleanroom environment. This was to confirm the absence of significant levels of hydrocarbon contaminants of unknown origin and composition in the lander which might, through deposition, compromise the integrity of the Gas Analysis Package. The monitoring, which showed peak levels below 4ppm even when performing cleaning activities using isopropanol, and baseline levels below detectable limits (<0.1ppm), demonstrated that this is not likely to have occurred. In particular, significant levels of hydrocarbons were not observed during times of peak vehicle activity on the site, demonstrating the efficacy of the carbon filter on the air intake. However, there was a low level of cleanroom-activity based VOCs, typically peaking at 0.5-2ppm by the end of daily operations, which is a combination of cleaning activity (IPA) and the VOCs resulting from human activity (possibly propionic acid in perspiration, methane (though only poorly detected) and other organics). Whilst their presence was undesirable, rigorous efforts to understand the relative compositions, or remove them, were not possible in the timeframe of the Beagle 2 mission.

* During one of the Beagle 2 Progress Review Meetings, a NASA/JPL Planetary Protection Consultant remarked “it would be a pleasure to work with you guys because everyone cooperates in a common cause”.

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6.1.6 Occupational Health Initial screening and ongoing monitoring was performed to reduce the risk of individuals unsuitable for the cleanroom being selected for critical operations, and was done several weeks before commencing work in the cleanroom. The initial screening was similar to that performed for new employees in other cleanroom–user industries. In our experience, only two individuals were excluded on this basis, for medically trivial chronic fungal or skin conditions. We did not detect in our cleanroom worker population any “high shedder” individuals (reputedly 1:60 of the general population), whose skin condition meant additional shower activity was required before cleanroom working. The monitoring was on a monthly basis for marker organisms (esp. Streptococcus species) which may have asymptomatically made the operator a greater risk to the cleanroom/hardware. In practice, this was likely to be picked up in the course of normal cleanroom working anyway, but here was an additional confidence that the cleanroom worker population were not, through ignorance, introducing a greater risk to the hardware than was necessary. 6.1.7 Microbial – AAF (Cleanroom, MGSE, EGSE) In the case of the microbiological monitoring of the environment, data is analysed blind by an independent external laboratory accredited to ISO9001 and UKAS standards (RSSL). A custom service to provide rapid response was negotiated with the supplier, based on same day processing of samples, and 3 day delivery of results using a fax back form (example shown in Appendix 7). Assay methodologies are based on the UK Medicines Control Agency’s “Orange Book” (Rules and Guidance for Pharmaceutical Manufacturers and Distributors) and from NASA-derived protocols from NHB5340.1B, including:

• Settle Plates • Contact Plates • Active air sampling • Active surface sampling (swabbing/witness plates)

Warning and action limits are set for certain of these activities for management purposes, whereas others are for project information/record only. Routine cleaning as part of the cleanroom operation addressed much of the microbial contamination. Generally, by the time data describing the contamination level of a cleanroom surface was received, that surface had already been cleaned at least once and, in cases in the Aseptic Assembly Area where surfaces were cleaned twice a day, potentially six or eight times. However, in less clean areas of the AAF (Primary prep, Initial Change) a rising trend in contamination levels was periodically addressed by emptying the room completely, wiping all surfaces with 70% IPA in sterile water, then 70% IPA cleaning each item as it was re-introduced to the area (required twice for Primary prep. area during the 6 month build period). 6.1.8 Microbial – Spacecraft In the case of the spacecraft microbiological monitoring, data is again analysed blind by the independent external laboratory accredited to ISO9001 and UKAS standards. Assay methodologies are based on NASA-derived protocols from NPG5340.1D, principally active surface sampling by direct swabbing or indirect swabbing using witness plates. The only significant modification to the NASA heat shock protocol was the substitution of polyester swabs for cotton buds as the material shed from the combination of cotton and wood

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splints was deemed to be unacceptable from a science perspective. Formal validation of this change was not performed, but trial inoculation and recovery experiments did not show significant differences between the two methods. During the build phase for Beagle 2, microbial sampling of the spacecraft hardware was done on a daily basis, and candidate sites for sampling were selected based on perceived risk. However, there was some constraint around the physical size of Beagle 2 as to how many times an area could be sampled, both in terms of the performance of the item being sampled (eg thermal control surfaces are potentially degraded by sampling with the polyester bud) and how representative the sample area is of a surrounding surface when it has been swabbed multiple times. Cleaning after contamination found was performed using surface swabbing with 70% IPA in sterile water, the standard cleaning agent used in the cleanroom. Although conceivably possible, it was never the case that any of Beagle 2 had to be disassembled in order to clean an item where contamination was detected after further items had been built on top. 6.2 DISCUSSION OF MONITORING The success of the Beagle 2 build from a PP perspective demonstrated that the monitoring approaches were adequate to the task. However, it is unclear whether any reduction in scope or intensity of the monitoring activity would compromise PP for future missions – every realistic approach was addressed at a conservative level for Beagle 2. The policy with Beagle 2 was to build to the best possible levels rather than to simply comply with the IVA classification. Other space craft designed to measure carbon and its compounds would likely also aspire to “only the best is good enough”. It is not clear what the additional risk would have been, had less rigour been applied. That notwithstanding, there are clear areas where limitations of the processes and procedures presented a risk to the project, both in schedule and absolute terms. The whole mission depended on our not irreversibly compromising the microbial cleanliness of the lander. This was achieved by a combination of good judgement, skill and good fortune. But had there been an instance of microbial contamination of the spacecraft, the intrinsic delay in the monitoring procedure (3 days from sample taken to the first microbial result) would have compromised the schedule significantly. This would have been particularly so had the contaminated item been built over or bonded in position. Hence a fundamental of the monitoring should drive the spacecraft design towards fixings rather than adhesives, connectors and plugs rather than soldered electronics, all of which add mass to the project, but reduce PP/schedule risk. More broadly, whilst the established microbial culture technique is the only validated method (and is simple, widely applicable, reproducible and proven), development of a more rapid alternative, which may be less selective and which will perhaps detect dormant cells as well as actively growing ones, is desirable. Future missions should consider PCR, LAL testing and/or ATP technologies as management indicators, even before any of these is validated for formal planetary protection purposes.

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7. REVIEW OF “OFF SITE” PLANETARY PROTECTION ACTIVITIES

The Beagle 2 project utilised and involved the capabilities of multiple organisations in several countries. The nature of the project means that planetary protection precautions needed to be imposed on some of these organisations to maintain the integrity of the overall PP implementation. 7.1 GENERAL BIOBURDEN PRECAUTIONS As part of the initial bioburden assessment, all suppliers were required to give indications of the level of cleanliness of the items being supplied, based on the manufacturing environment and cleaning heritage of the item (with reference to the Appendix A of NASA document NPG8020.12B) (see also chapter 8 below). 7.2 SPECIFIC BIOBURDEN/MANUFACTURING ENVIRONMENT MANAGEMENT Due to deviations from the PP Implementation Plan as a result of incompatibilities between materials and sterilisation processes, themselves arising from engineering changes, bioburden control was imposed on specific sub-contractors. This required them to complete tasks in cleanroom conditions which would otherwise have been performed in a general (uncontrolled or class 100,000) manufacturing environment. 7.2.1 Back Cover Thermal Protection bonding The original strategy for the back cover sterilisation was dry heat of the assembled back cover. However, a change in the adhesive used to bond the back cover structure and skin meant that this was not possible. This meant individual components had to be sterilised and then assembled. The fitting of the thermal protection (TP) tiles to the back cover at EADS in Bordeaux was a protracted manually intensive task, and, if not controlled, could have resulted in trapping of significant numbers of contaminant organisms between the tiles and the carbon fibre skin. The solution was to perform all tasks in a temporary class 1000 cleanroom, installed at EADS, with all hardware, MGSE etc. sterilised as per the AAF and all activities performed to a revised protocol using staff wearing the same garment regime as for the AAF. This activity necessitated training the staff involved, and monitoring both the cleanroom environment and the bioload of the cleanroom and hardware. The project was fortunate in that EADS was able to divert staff with suitable expertise to this activity, and a satisfactory result was obtained. Even so, the reality is that there is an adverse effect on the bioburden, since the cleanliness of the bonded surfaces was to class 1000, rather than sterile (this is accounted in Chapter 8). This approach would not therefore, be compatible with a Class IVb or IVc mission. 7.2.2 Back Cover Extension In a further post-sterilisation modification to the back cover, an extension was fitted to make accommodation of the airbags easier.

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The solution was again to perform all tasks in the same temporary class 1000 cleanroom, installed at Astrium UK, with all hardware sterilised as per the AAF and all activities performed to a revised protocol using staff wearing the same garment regime as for the AAF. This activity again necessitated training the staff involved, and monitoring both the cleanroom environment and the bioload of the cleanroom and hardware. A satisfactory result was again obtained, but with the same adverse effect on the bioburden, since the cleanliness of the bonded surfaces was only to class 1000, rather than sterile (this is accounted in Chapter 8). 7.2.3 Vibration Testing The final post-assembly test for Beagle 2 was a workmanship vibration test. Since there are a limited number of environments where a vibration test can be performed on a radioactive, explosive, pressurised item, an off-site facility was again required (AWE). The baseline approach based on the PPIP (BGL2-OU-PL-007) was to erect a temporary cleanroom enclosing the vibration table together with the MGSE/EGSE and chamber for Beagle 2. On this occasion, the requirement was only to class 100,000 since Beagle 2 was closed with HEPA filter and bioseal in place, although it performed very much better (to equivalent of about class 2000 when manned). The over-pressurisation event that occurred during this test programme meant that significant diagnostic and readjustment activities were required. The over-performance of the cleanroom relative to the specification meant that these activities could take place in the cleanroom at AWE, rather than shipping back to the AAF, reworking, then shipping back to the vibration test facility. This was a significant saving to the schedule, and was only possible because of the (albeit undesigned) cleanroom overperformance. However, access controls, modifications to the garment regime and microbiological monitoring were instigated to preserve the bioload on Beagle 2 at as close as possible to its “ex-AAF” level during the rework activity. 7.2.4 Transit to Toulouse and Fit Check at Interspace Following completion of the assembly, test and closure activities in a Class 100 environment in the UK, the Beagle 2 probe was transferred to a custom-built mobile transport chamber in a Class 100,000 environment. This was then moved from the cleanroom into the custom-built 10’ ISO container (see figure 7.1 below) and secured. The original intention was for the transport chamber to be flushed with clean (white spot) nitrogen and filled to a slight overpressure to allow for leakage in transit. However, this was found to be unnecessary, as the leak rate on the transport chamber was so low that it could be considered a sealed environment for the purposes of shipment over several days. Beagle 2 was shipped by road to Toulouse. The Planetary Protection Manager accompanied the load in the escort vehicle. On arrival the probe was transferred in the sealed transport chamber from the load area into a Class 100,000 area. On opening the chamber, a cartridge filter assembly comprising Molecular Sieve, Carbon and HEPA filters was fitted to the Beagle2 HEPA filter.

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This was the standard approach whenever the Beagle2 Probe was not in the transport chamber, ensuring it “breathed” not only filtered, but carbonaceous-free air in whatever environments it experienced. Figure 7.1: Beagle 2 Transport Chamber

7.2.5 Flight to Baikonur and the Launch Campaign Beagle 2 was shipped by road from Intespace to Toulouse airport, by air from Toulouse to Baikonur airport and by rail from the airport to the MIK112 spacecraft assembly facility at the Baikonur cosmodrome. The Planetary Protection Manager witnessed the loading of the ISO container, with Beagle 2 inside, onto the aircraft at Toulouse. The container was accompanied by a member of the EADS-Astrium team to Baikonur, with the Planetary Protection Manager following on a later flight (ideally this should have been the same flight but the MEx project team were not aware of this requirement, and the B2 project team were not aware of the restricted accommodation on the flights until it was too late). On arrival at Baikonur, the security tagging fitted to the ISO container doors in Toulouse were undamaged, indicating that the load was not compromised/accessed during the journey, and Beagle 2 had remained sealed in the transport chamber. The facilities at Baikonur, as is required for all spacecraft assembly areas, have cleanroom standards maintained to Class 100,000 and this was confirmed independently by the Beagle 2 PPM. Following battery charging the Beagle 2 probe was fitted to the Mars Express spacecraft. After final IPA cleaning of the external surfaces of the probe, the sterile flight MLI

Key: 1: (Outer) ISO Container 2: Stainless Steel Chamber3: Trolley for 2

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was fitted. The internal microbiological status of the probe was not compromised, being protected by the bioseal and the cartridge filter assembly. However, following the installation of the MLI, it was assumed that the outside surfaces of the MLI were degraded to the level of the cleanroom environment, ie Class 10,000 in the PPF. During this period, there was an incidence of volatile organic contamination of the PPF area due to a painting activity outside the cleanroom adjacent to the intake air vents. Analysis of witness plates routinely maintained in the PPF gave organic contamination at the level (maximally) 4.5x10-8g/cm/week. The cartridge filter assembly will have removed this, had there been significant gas flow into the probe. However, since the PPF area is temperature and pressure controlled, it is not expected that there would not have been any appreciable gas flow into the probe from the environment in any case. The MEx-Beagle 2 integrated spacecraft was transferred from the PPF area to the UCIF area under a mobile “clean tent” at better than Class 100,000 under Mars Express team supervision (this activity was not witnessed by the Beagle 2 team, however Mars Express must also be maintained at better than Class 100,000 in any case). The cartridge filter assembly remained in place during this operation so the organic status was not compromised. In the UCIF, the Fregat upper stage was integrated with the MEx/Beagle 2 spacecraft. This entity was then encapsulated within the fairing, which had had an additional IPA clean to assist cleanliness for Beagle 2, at the request of the MEx team. Immediately prior to encapsulation, the exposed MLI on the probe was swabbed as a final indicator of microbial contamination of the outside surfaces. This was done prior to removal of red tag items for safety reasons, however no additional contact or contamination opportunity was observed during the red tag item removal sequence. The duration between start of red tag item removal and mating of the spacecraft with the fairing was approximately 2 hours. From this stage onward, the cartridge assembly was removed, and the Beagle free to “breathe” from the local environmental air. From this point onward the launch campaign proceeded under the management of the Mars Express team without the involvement of the Beagle 2 Planetary Protection Manager, except in the case of adverse occurrence (none was experienced). The encapsulated spacecraft in the fairing was closed and moved from the UCIF to the railhead (200m inside the building) before transfer to the railcar. Once on the railcar, a Class 100,000 nitrogen supply allowed positive pressure to be maintained inside the fairing to protect the spacecraft from the local external environment (essentially maintaining cleanliness and protecting against temperature and humidity changes). This is important since, although the journey is a short distance (30km) the duration is almost 24hours. When actually measured, the air quality at the inlet fairing was found to be Class 10,000 or better. However, since the fairing was closed to the outside environment, the opportunity for contamination was minimal After integration with the Soyuz launch vehicle in a Class 100,000 environment, the completed spacecraft/launch vehicle assembly was moved to the launch pad in horizontal configuration, by rail, a distance of 1km taking an hour. For the whole of this period, the

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nitrogen supply was attached and when measured, the air quality at the inlet fairing was Class 10,000 or better. However, for a short period during the next phase when the assembly was raised to vertical, the nitrogen was detached. The detachment process was done rapidly (1-2seconds) to minimise risk of material ingress into the fairing. Once vertical, the nitrogen supply from the launch tower was reconnected to maintain the overpressure/cleanliness regime for approx 3 days (29/5/03-2/6/03). During this period, access was minimal, since most of the activity focused on Soyuz preparation. When measured, the air quality at the inlet fairing was Class 10,000 or better. Shortly before launch, the nitrogen supply was removed (4hours). For this period, the fairing was closed against the environment, but not sealed. In the judgement of the PPM, the interior microbiological and organic status for a IVA mission were not compromised by this activity. However, for a more stringent (IVb or IVc) mission, additional precautions may be necessary: in the case that the fairing could not be modified (likely) to be a) sterile and b) sealable. In this case it might be expected to need a bioshield which protects the spacecraft from the environment until deployment in space (cf Viking).

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8. REVIEW OF THE BIOBURDEN ANALYSIS OF BEAGLE 2

8.1 INITIAL ESTIMATES OF BIOBURDEN The analysis of bioburden for Beagle 2 leans heavily on the heritage of previous NASA missions. As part of the Viking programme, NASA developed conservative indicators of the numbers of organisms present on a surface, based on the cleanliness of the environment in which the surface was equilibrated, as shown in Table 8.1 below: Table 8.1: Pre-sterilisation Surface Microbial Density (from NASA document NHB8020.12B).

• Uncontrolled Manufacturing 1x106/m2 of which 1x105/m2 are spores

• Class 100000 Manufacturing 1x105/m2 of which 1x104/m2 are spores • Stringent Class 100000 Manufacturing 1x104/m2 of which 1x103/m2 are spores

• Class 10000 Manufacturing 5x103/m2 of which 5x102/m2 are spores • Stringent Class 10000 Manufacturing 5x102/m2 of which 5x101/m2 are spores

These figures were used for parametric estimation of the number of organisms on spacecraft parts prior to sterilisation, unless a representative direct microbiological measurement could be obtained (eg if surfaces were unaccessible to sampling, or if items were supplied after sterilisation by the sub-contractor). Exposed surface area estimates were obtained from interrogation of CAD drawings (preferred) or by measurement and estimation based on surface “roughness”. Discretion was used in terms of the “resolution” at which a surface was considered, so for example the parachute was considered as two flat sides even though at the micro-level it is comprised of fibres, whereas all the internal surfaces of the hexagonal structure in the aluminium honeycomb were accounted. By this method, for Beagle 2, a 900mm diameter, 650mm high probe, it was estimated that the surface area was 1120.62m3, hosting an estimated 11,157,460 (landed) spores before sterilisation (clearly some sterilisation was necessary!). Encapsulated organisms (trapped within solid materials) were estimated using mass and volume measurements/estimates. The conservative figure of 150 spores/cm3 was used for non-metallic materials, based on data from NASA procedures for electronic components prior to sterilisation. This was then reduced where sterilisation processing was done using a “penetrating” technology (dry heat, irradiation), or kept unchanged when sterilisation was using a “surface” sterilising technology (hydrogen peroxide gas plasma, steam, IPA wiping). 8.2 POST STERILISATION BIOBURDEN Each of the subsystems was processed using the appropriate sterilisation technology, and the bioburden estimate revised according to the following parameters:

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• Dry heat – 4log reduction (surface and encapsulated) • Gamma Irradiation – 6log reduction (surface and encapsulated) • Hydrogen Peroxide Gas Plasma – 6log reduction (surface only) • IPA wiping – 2log reduction (surface only) • Moist heat – 4log reduction (surface only)

Following these activities, the bioburden for the complete (but unassembled) spacecraft is estimated at 87,386 (landed) spores. The majority of these are embedded within the (hydrogen peroxide-sterilised) PAW instruments. It is considered that this is an overestimate, since it is anticipated that the value of 150 spores/cm3 used for the calculation is a conservative number in the context of mass produced electrical/electronic components from clean manufacturing environments. However, in the absence of measured data or further desk research into component heritage (neither of which were possible in the context of the Beagle 2 project), this is the number that must be taken. 8.3 BIOBURDEN ESTIMATE INCREASE DURING INTERGRATION After sterilisation, each sub-assembly was stored in its sterilisation packaging until integration. Once the sealed item is opened, the bioburden can only increase with handling and exposure to the assembly environment. This was monitored directly by the NASA method as previously described in Chapter 6. However, with stringent control over all the usual environmental sources of spore contamination, it would be expected that the number of spore forming organisms transferred to the spacecraft hardware would be quite small, resulting in the majority of samples showing zero counts for spore forming bacteria. This was indeed observed to be the case, matching the experience of the Pathfinder team where surface recontamination was estimated at around 31000 (Mars Pathfinder Planetary Protection Report - Pre-Launch Report). The estimate for Beagle 2 was 13,813 spores (at 3σ). Even this low figure is likely to be an overestimate, since to perform the statistical analysis using a Poisson distribution method, groupings of zero results were rounded up to 1, or were summed together with positive samples from other areas to obtain a conservative “average” bioburden for an area. 8.4 POST-ASSEMBLY BIOBURDEN STATUS After completion in the UK, microbial bioburden analysis was limited to the outside surfaces of the aeroshell plus the MLI since the interior was inaccessible and was in any case always protected by the HEPA filter. However, swabs were taken both in Toulouse and in Baikonur immediately prior to encapsulation. In all cases, no growth was detected. In the case of the aeroshell, this is likely to have been due to the inhibitory effect of the (phenolic containing) thermal protection layer. In the case of the MLI, it might be expected that the material would be better than the 300 spores/m2 cleanliness level, and therefore below detectable limits for the swabbing method.

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9. SUMMARY AND CONCLUSIONS The Beagle 2 project team managed, through a combination of skill, judgement, luck and the commitment of a team of individuals, to produce a spacecraft which, after stringent external review, was considered to have met the COSPAR requirements for a category IVa mission. The solution adopted to resolve the planetary protection problem was the best available option for the specific case of Beagle 2. Many lessons were learned, both generic to all Mars robotic mission types and also to future missions specifically considering aseptic assembly options. The key ones of these are highlighted below: 9.1 POLICY AND PROJECT MANAGEMENT

• Involve Planetary Protection early in mission concept design. Early design decisions/omissions in the Beagle 2 project resulted in a complex aseptic assembly task which could have been simplified had a different level of PP involvement been possible.

• End to end PP of whole spacecraft from individual components until launch needs to be developed & followed through early, with the participation of all relevant organisations and necessary interfaces agreed.

• Training in PP issues for design and AIT staff is of invaluable benefit in integrating engineering with the PP function.

• Subcontractors need to be aware of their obligations in terms of material information disclosure/cleanliness specifications to meet PP requirements.

• Knowledge is better than estimates in PP – e.g. knowledge of manufacturing processes (eg high temperature curing) can reduce/eliminate the requirement for subsequent sterilisation, negating the requirement for conservative assumptions and reducing the cost/risk associated with PP compliance.

• The Beagle 2 method is an answer, but not necessarily the PP answer for future missions.

• Access to full information about materials and processes (not fettered by late ITAR applications or IPR issues is critical to developing optimal PP implementation for a mission.

• The PP function needs to be resourced early to iterate with the design team.

• Consider system resource vs PP risk at a system level (a few 10s of grams mass vs risk of PP failure may be a price worth paying, launcher requalification vs statistical reduction of 1 order of magnitude in surface bioload may not be)

• As at the end of the Beagle 2 mission, significant progress is needed in microbial monitoring capability to reduce schedule risk associated with the monitoring process.

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9.2 TECHNICAL IMPLEMENTATION OF ASEPTIC SPACECRAFT ASSEMBLY

• Rehearse activities at Engineering Model/Qualification Model stage, outside the critical path for flight hardware delivery. This has a number of benefits: i) it enables an understanding of cleanroom performance with respect to PP implementation and the AIT requirement ii) it will also identify teething problems for new facilities/novel processes iii) it will speed up procedures and processes on the flight hardware, which will most likely be at the schedule-critical phase of the project.

• Labelling and stock control systems for sterilised hardware, compatible with cleanroom operations, need to be set up and maintained.

• The QA/PA interface and processes need to be agreed early in any facility/AIT design process, in order to allow sign off to proceed without undue risk of contaminating the spacecraft.

• For tools with moving parts which are to be baked and/or repeatedly cleaned with IPA, dry lubricant coating (WS2/MbS2) can be utilised.

• From a PP re-work (risk management) perspective, fixings and connectors are preferred to adhesive bonding and soldering.

• Solvent/cleaning agent control is an important issue. Biocides need to be used in cleanroom cleaning. Standard cleanroom detergents contain aggressive chemicals which cannot come into contact with spacecraft systems. IPA or ethanol are acceptable in most space hardware environments.

• Where access is restricted, quality communication systems are important to facilitate the task in hand. Avoid spurious blanket constraints in the use of optical/RF/IR IT/comms equipment as these technologies have great potential in easing cleanroom working.

• For any new facility, care needs to be taken in the fit-out at a detailed level, since most cleanroom contractors/suppliers will not be familiar with the combined needs of facilities requiring sterility, cleanliness and ESD control.

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10. REFERENCES

10.1 Cited References Beagle 2 Probe First Interface Thermal Mathematical Model (Beagle 2 Project doc BGL2-RAL-TN-0010) DeVincenzi, D. L, P. D. Stabekis and J. B. Barengoltz. Proposed new policy for planetary protection. Adv. Space Res., 3 13 (1983). DeVincenzi, D. L, P. D. Stabekis and J. B. Barengoltz. Refinement of Planetary Protection Policy for Mars Missions. Adv. Space Res., 18 311 (1995) Mars Pathfinder Planetary Protection Plan (JPL D-11690), Jet Propulsion Laboratory, 1994 Mars Pathfinder Planetary Protection Report, Pre-launch Report (JPL D-14035 Part I), Jet Propulsion Laboratory, November 1996 NHB 5340.1B Microbial Examination of Space Hardware, NASA NPR 8020.12C Planetary Protection Provisions For Robotic Extraterrestrial Missions, NASA (replaces NPG 8020.12B in force at the time of the Beagle 2 mission). Planetary Protection Plan for Beagle 2 (Beagle 2 Project doc BGL2-OU-PL-005) Planetary Protection Implementation Plan for Beagle 2 (Beagle 2 Project doc BGL2-OU-PL-007) Planetary Protection Pre Launch Report for Beagle 2 (Beagle 2 Project doc BGL2-OU-RE-008) Planetary Protection Post Launch Report for Beagle 2 (Beagle 2 Project doc BGL2-OU-RE-009) Rules and Guidance for Pharmaceutical Manufacturers and Distributors 1997 (“Orange Book”) Medicines Control Agency HMSO UK1997 Rummel, J.D. and L. Billings Issues in Planetary Protection; History, Policy and Prospects, COSPAR Information Bulletin 160 31 (2004) Rummel, J.D., P.D. Stabekis, D.L. DeVincenzi and J.B. Barengoltz COSPAR’s Planetary Protection Policy; A Consolidated Draft Adv. Space Res., 30 1567 (2002) Sims, M. R. (Ed) Beagle 2 Mission Report Univ of Leicester UK (2004) ISBN 1 898489 35 1

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10.2 Selected Other References Horneck, G Exobiological experiments in Earth orbit, Advances in Space Research 22, 317 (1998) Mileikowsky C et al. Risks threatening viable transfer of microbes between bodies in our solar system, Planetary and Space Science 48, 1107(2000). Nicholson, W. et al. Resistance of Bacillus Endospores to Extreme Terrestrial and Extra-terrestrial Environments. Microbiology and Molecular Biology Reviews 64 548 (2000) Starsem – The Soyuz Company – More information on the launch facility used for the Mars Express mission: www.starsem.com Wharton, D Life at the Limits, Cambridge University Press UK 2002

http://www.starsem.com/

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11. APPENDICES NOTE: The attached appendices are documents as created during the Beagle 2 programme, included at their latest issue number. They are included for information only to enhance the understanding of the reader. Where a discrepancy/conflict between the information in the appendix and in the main document occurs, this is likely to be due to an updating process over the course of the programme. The main text will reflect the most up-to-date situation. Appendix 1 DRY HEAT STERILISATION TECHNOLOGY

Appendix 2 HYDROGEN PEROXIDE GAS PLASMA TECHNOLOGY

Appendix 3 OPEN UNIVERSITY ASEPTIC ASSEMBLY FACILITY SPECIFICATION

Appendix 4 BEAGLE 2 CLEANROOM OPERATORS TRAINING PROGRAMME

Appendix 5 OVERVIEW OF CLEANROOM WORK DISCIPLINES FOR BEAGLE 2

Appendix 6 CLEANING RECORD SHEET

Appendix 7 ENVIRONMENTAL MONITORING MICROBIOLOGY RECORD SHEET

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Appendix 1 DRY HEAT STERILISATION TECHNOLOGY 1.1 INTRODUCTION The dry heat sterilisation process relies on the oxidative degradation of biological entities during an extended high temperature incubation under conditions of controlled humidity and pressure. In this process, biological molecules such as DNA and proteins are rendered dysfunctional, thereby killing the contaminating organism. The lethality of this process to micro-organisms is strongly dependent on the humidity, which must be maintained at below 25%. It is therefore insufficient to seal the item to be sterilised in a chamber and bake at the desired temperature, as a high or variable water content in the item may compromise the process: each of the parameters of temperature, dwell time and pressure (and thereby humidity) needs to be controlled. The rate of kill is dependent both on the temperature and the number/type of organisms present. Other industries have developed ranges of temperature and time parameters to achieve sterility after contamination by worst case (ie temperature resistant) organisms. These have been used in developing strategies for sterilising space hardware, notably for the Viking and Pathfinder programmes. The nominal conditions adopted for Beagle2, as developed by NASA for Pathfinder, are:

50hrs cycle time (plus heat up cool/down) at 115ºC setpoint at or below 1.58Torr Following these conditions, a kill level of 104 can be claimed under the NASA protocol without direct measurement of changing levels of contaminant microorganisms. To claim higher levels of sterilisation, statistically valid direct measurements must be used. In practical terms, the number and sizes of surfaces which must be sampled means that this approach is unsuitable for use with Beagle2, constraining the programme to use the former method. 1.2 THEORETICAL/HISTORICAL BACKGROUND 1.2.1 Sterilisation Time and Temperature The expression governing time and temperature for the Beagle2 heat sterilisation process, as previously adopted by Pathfinder, is: t = 5 x 10(125-T)/21 where: t = required minimum sterilisation time (hours) T = Sterilisation temperature (ºC) This is based on NASA planetary protection specifications (D, time to kill 90% of contaminant organsims, = 1 hr at 125ºC: Z, temp range over which kill changes by a factor of 10 for a given value of D = 21ºC, with the approach that application of the processes will include treating mated surfaces to achieve the 4log reduction.

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Hence for a hardware item sterilised at setpoint 110ºC, with a temperature gradient of +/-6ºC, the minimum temperature will be 104ºC, on which the 50hr nominal cycle is based. It also allows for local temperature overshoot to remain below the 125ºC of the specification used for Beagle2 hardware It may be possible on a case by case basis to modify the sterilisation protocol to gain schedule benefits. For example, sterilising at 120ºC with a measured minimum at 115ºC would reduce the sterilisation time as follows: t (hrs) = 5 x 10(125-115)/21 = 15hrs However, for scheduling purposes, 50hr should be allowed for the heat sterilisation process. 1.2.2 Importance of humidity control The survival of bacteria at high temperature is strongly influenced by available water, i.e. relative humidity. This is typically greatest in the 30-50% humidity range. With high humidity being problematic in space hardware terms, low humidity is used to promote cell death. The values for the NASA PP Specifications are derived from data using maximum 25%RH at STP (0ºC and 760 Torr). As previously noted, amounts of water vapour evolved from different workpieces at high temperature make it necessary to control humidity. NASA have historically used two approaches: 1) Circulating dry nitrogen gas oven: Incubate at standard pressure, flush with dry nitrogen and measure the humidity of the exhaust gas, dry and recirculate (Viking). 2) Vacuum oven: Utilises the fact that the relative humidity is equivalent to the ratio of the partial pressure of water (vapour) to the saturation vapour pressure of water. The partial pressure of water is a valid expression of the absolute humidity. At STP the saturation vapour pressure is 4.6 Torr, hence for a maximum humidity requirement of 25%, the maximum partial pressure of water would be 1.15Torr. At a temperature other than STP, the partial pressure in Torr is given by: Pmax = 1.15 (T+273)/273, where T is the sterilisation temperature in Centigrade, hence for 104°C, Pmax = 1.15 x (104+273)/273 = 1.58 Torr. In the process, the total pressure in the oven chamber represents an upper limit for the partial pressure of water, hence it is sufficient to maintain the total pressure at below 1.58 Torr to maintain the humidity at below 25% (Pathfinder). Beagle2 is adopting the second approach as the easier of the two approaches to set up, operate and manage.

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1.3 BENEFITS The dry heat process is simple to perform and monitor, well understood and with a proven track record in spacecraft hardware manufacture. Much spacecraft componentry is already qualified to the temperatures used in dry heat sterilisation because potentially it could experience that temperature in the normal operating environment. Compared to other sterilisation technologies, the process has no chemical residues, has negligible environmental impact and wide compatibility with materials. Critically, it is one of only two mainstream sterilisation processes (the other being irradiation) where the effect is penetrating as opposed to surface-only (ie it can sterilise encapsulated organisms and organisms within sealed areas). The sterilisation performance is sufficient to control the levels of bioburden typically found on spacecraft hardware, and can therefore be considered adequate for the processing of Beagle2 components. 1.4 LIMITATIONS The limitations of the dry heat sterilisation method are largely to do with material compatibility. If the material cannot withstand a 125ºC soak without suffering degradation, then it cannot be heat sterilised. In addition, the system is unable to process volatile liquids. Compared to other technologies, the process is slow (essentially 2 days, compared to moist heat at 121ºC for 15 minutes). As with all the sterilisation technologies, the process kills contaminant organisms, but does not remove them. To meet the particulate cleanliness requirements for Beagle2, the item should first be solvent cleaned to remove as many organisms as possible, and then sterilised.

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2 SET UP AND PERFORMANCE OF DRY HEAT STERILISATION OF BEAGLE2 COMPONENTS

The following series of stages is intended to be used as an Operating Procedure for members of the Beagle2 Consortium who want to use dry heat for sterilisation/test sterilisation of spacecraft hardware. 2.1 CHECK COMPATIBILITY Clearly there are incompatibilities between the dry heat sterilisation method and some materials/components, which degrade the component either in terms of structural integrity or performance. It is essential to check against the existing data before committing valuable hardware to the process. In the case of sub-assemblies, it is important to consider all the materials present and their processing histories. This includes coatings, adhesives, lubricants etc. as well as the main structural materials of the components. 2.2 SAMPLE PROCESSING A critical approach to compatibility of process and materials is essential for sterilisation technologies. The more complex an item, and by inference the more different types of material are present, the greater the risk of an incompatibility. This may even be due to differences in batches/grades/manufacturers of a given material. The lowest risk approach is to sterilise a completed flight-representative item, expose to a realistic life test and then test performance. However for Beagle2, this is not a viable option for flight hardware due to lack of time. It is important therefore to gain as much information about likely effects as possible before committing flight hardware to the process. The approach should be, after compatibility checking, to test sub-assemblies and then prototypes before processing flight items. 2.3 CHECK AVAILABILITY The long soak time for this process means that planning ahead is essential. In order to co-ordinate this activity, times should be booked through the Planetary Protection Manager (see Appendix 1) or other AAF staff, who will maintain a booking record and will decide whether two or more items can be co-sterilised on the same cycle. In the event of conflict, the Planetary Protection will coordinate with the Project Manager and AIV Manager to determine priority, based on schedule requirements.

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2.4 THE PRE-PROCESS MICROBIOLOGICAL ASSAY Ideally, the item will then be sampled for microbiological testing. The test is based around the NASA NHB5340.1B process for monitoring microbiological contamination of space hardware. Essentially, a 25cm2 sample area is swabbed and the swab rinsed in water before transferring to microbiological growth media; in the case of detecting heat resistant spores for COSPAR monitoring processes, this is following a “heat shock” procedure, which is selective for only the spores of interest. The number of cells obtained during this procedure can then be related back to the COSPAR requirements and the project-specific requirements in the PPIP. This process takes around 3-4 days before the micro-organisms grow sufficiently to be analysed. 2.5 PACKAGING AND STORAGE For the Beagle2 hardware items to be sterilised, some will require ESD protection, others not. All will need the sterility of the item to be protected once the sterilisation cycle is finished. As a principle, all items being sterilised must be double wrapped going into the steriliser chamber. This allows the outer layer to be discarded as the item is transferred into the AAF. 2.5.1 For ESD Sensitive Materials

i. Use of grey metallised anti-static materials is preferred to the static-dissipative “pink poly”, which will melt.

ii. Bags should be closed with tape over the end to permit air evacuation. iii. Closed bags can then be put into single Tyvek pouches and sealed. The item to be

sterilised is now ready for sterilisation. 2.5.2 For non-ESD sensitive items

i. Whilst any non-sealed packaging layer can be used as the primary packaging, it is recommended that a Tyvek pouch is used, as this will give a complete microbial barrier when the item is storage.

ii. If another (non-permeable) bag type is used, thermal stability to 125ºC needs to be confirmed before use. In use, the bag should be closed with tape over the end to permit air evacuation.

iii. The item can then be put in a second (Tyvek pouch) layer and sealed. The item to be sterilised is now ready for sterilisation.

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In the case of items too large for available Tyvek pouches, it is intended to make reel or tray wrap materials available. In this event, the kapton tape/heat sealing should be used to custom-make a sealed package. 2.6 INCLUSION OF BIOLOGICAL INDICATORS A biological indicator (or “spore strip”) will be included with each operation of the unit. This is a method of proving the efficacy of the sterilisation cycle without compromising the sterility of the item being processed. Processed at the same time as the spacecraft hardware, the biological indicator contains 106

spores from a resistant bacterial strain. Following exposure to the process, these are assayed microbiologically. It is usual to find zero growth in the assay, indicating a microbial reduction factor of at least 6logs. For practical purposes, this indicates that items manufactured in an uncontrolled environment (i.e. with an initial bioburden of 105 spores/m2) will have zero survivors after the process (post-sterilisation Sterility Assurance Level = 10-1). However, the NASA standard process makes assumptions about the presence of temperature resistant spores which limits the maximum reduction factor which can be claimed to 4logs, giving an post-process SAL of 101 spores/m2. 2.7 PROCESSING Items arriving at the AAF need to be inspected by a competent engineer before being released for sterilisation. The item will then be packaged for sterilisation by OU technical staff under the guidance of the engineer (whether ESD protection is required, number of layers). Under normal circumstances, items will be double wrapped. The item will then be transferred into the Dry Heat Sterilisation chamber. Thermocouples/ data loggers will be used to ensure minimum temperatures are maintained. A pre-incubation to 50ºC will be set up to confirm the temperature range across the workpiece for the sterilising incubation. The chamber will then be heated to its target temperature (115ºC) from ambient at a max rate of 2.5ºC/min and the chamber will be evacuated down to 1 Torr. The timer will then commence a (eg) 50hr countdown. At the end of the (eg) 50hr period, the chamber will be repressurised and cooled to ambient at a maximum rate of 2.5ºC/min. 2.8 POST PROCESS HANDLING

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Sterility of the item following processing will only be compromised if the packaging is breached and the item is exposed to a non-sterile environment. It is therefore important to minimise the risk of this happening. Double bagging should be retained if an item is outside a clean area (this may mean rebagging if an item is required to leave a cleanroom and then come back). Sub-contractors and other workers need to be made aware of the need to retain sterility of items post-processing, particularly if working outside a cleanroom (e.g. at a test house). 2.9 RE-STERILISATION Some effects of sterilisation will be cumulative, resulting in increased degradation of performance after numbers of cycles. It is important that re-sterilisation options should be reviewed with the PPM on a case-by-case basis before committing items to further sterilisation.

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3 TEST PROGRAMME TO DATE 3.1 TESTING PERFORMED No testing has been performed to date, save that done as a result of high temperature stages of other manufacturing processes. The programme is reliant on hardware being supplied to its intended thermal stability requirements (see also section 4).

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4 RECOMMENDATIONS AND ADDITIONAL TESTING REQUIREMENTS 4.1 USE OF DRY HEAT STERILISATION The dry heat method is an effective method for sterilisation of surfaces and encapsulated material and is the preferred approach for use in the Beagle2 programme. The technique complements other approaches being used in the programme (see Appendix 2). 4.2 ADDITIONAL TESTING Whilst there is a good level of confidence that all components and subsystems earmarked for dry heat sterilisation will survive the process unharmed, there is risk in this approach. Dry heat sterilisation of relevant DM and QM items should form part of the qualification programme, once the facility is available.

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APPENDICES APPENDIX 1: CONTACT DETAILS ROLE NAME / AFFILIATION CONTACT BEAGLE2 PLANETARY PROTECTION Planetary Protection Dr J Andy Spry (JAS) +44 1908655169 Manager Open University [email protected]

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APPENDIX 2: STERILISATION COMPATIBILITY TABLE The table below is intended as a general guide to approaches to sterilisation of space hardware: Technology

Usage Strengths Weaknesses

Dry heat (e.g. 125degC for 50hrs)

Preferred Easy, reproducible, proven technology. Penetrating (sterilises throughout systems) Assists with/assisted by degassing routines

Not compatible with some componentry e.g. some polymers, batteries, magnets, pyros

Moist heat (autoclaving at e.g. 121degC for 20min)

Not widely used

Effective easily available well understood technology

Exposure of spacecraft systems to moisture is not usually desirable

Toxic Gas (e.g. using ethylene oxide, methyl bromide, formaldehyde)

Not widely used

Effective surface sterilisation technologies

Usually toxic to humans as well. Issues of compatibility with materials and residue removal.

Gas plasma (e.g. hydrogen peroxide gas plasma – Sterrad)

Newer technology with good potential

Effective low temperature method with good material compatibility

Process not well qualified for space hardware. Some material compatibility issues

Ionising Irradiation (i.e. gamma, electron beam)

Limited usage for specific applications

Penetrating technology – allows sterilisation of sealed volumes and e.g. packed parachutes. Suitable for non-heat resistant materials

Has accelerated aging effect. Not good for PTFE, PVC, acetal, polypropylene, electronics, optics

uv Irradiation/strong white light

Not widely used

Potential for surface/air/water decontamination

Requires “line-of-sight” i.e. can only sterilise transparent materials or top surfaces.

Vapour methods (e.g. freon, IPA)

Not widely used

Ultra-cleaning/degreasing processes give benefits in sterilisation

Difficult to achieve for large items. Toxic/unfriendly process

Solvent Cleaning (e.g. using ethanol/isopropyl alcohol)

Last resort plus routine cleaning

Easy, repeatable, cheap, manual process

Not effective against spores, except by removal (all others actually kill spores). Not compatible with all surfaces

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APPENDIX 2: HYDROGEN PEROXIDE GAS PLASMA TECHNOLOGY 1.1 Introduction The hydrogen peroxide gas plasma technology system relies on the biocidal activity of hydroxy- and peroxy- entities generated in the chamber during the plasma phase. These entities interact with biological molecules such as DNA and proteins, making them dysfunctional and thereby killing the contaminating organism. To achieve this sterility, the instrument cycles through five phases: vacuum, injection, diffusion, plasma, and vent. During the vacuum stage, the chamber is evacuated to 0.3 mmHg pressure. Items to be sterilised, are typically placed into the chamber sealed in a gas-permeable Tyvek pouch. A dose of liquid peroxide is then injected into the evacuated chamber through a heated injector nozzle, which both evaporates the aqueous hydrogen peroxide solution and disperses it into the chamber. The chamber temperature is controlled at a point somewhat warmer than room temperature, not exceeding 40°—45°C, to reduce the chance of condensation. The chamber pressure rises slightly during the injection phase as the hydrogen peroxide evaporates. The process can be considered fairly dry, since the relative humidity stays between 6 and 14%, and the equilibrium vapour pressure of water at 40°C is about 60 mmHg. During the diffusion phase (approximately 50 minutes in duration), the hydrogen peroxide vapour is allowed to permeate the chamber and completely expose all surfaces, including the instrument inside the Tyvek pouch, to the sterilant. At the completion of the diffusion phase, the chamber pressure is reduced to 0.5 torr, and the radio-frequency plasma discharge is initiated, which lasts for 15 minutes. In the plasma state, the hydrogen peroxide vapour breaks apart into reactive species that include free radicals. The combined use of hydrogen peroxide vapour and plasma safely and rapidly sterilises most instruments and materials without leaving toxic residues. Following the reaction, the activated components lose their high energy and recombine to form primarily oxygen, water, and other non-toxic by-products. In the final phase, the chamber is vented to atmosphere through a high-efficiency particulate air (HEPA) filter, re-evacuated, and vented again. The vapour purged from the chamber is vented to the atmosphere through a catalytic filter to decompose all remaining traces of hydrogen peroxide into water and oxygen vapour. 1.2 Benefits Compared to other sterilisation technologies, the Sterrad system offers a short cycle time (averaging 75 minutes), low temperature and humidity, no aeration requirement, no chemical residues, negligible environmental impact, wide compatibility with materials. The sterilisation performance is sufficient to satisfy the most stringent requirements of re-usable medical devices and is therefore more than adequate for the processing of Beagle2 components. In many instances, the compatibility of Sterrad is complementary to other technologies, giving the Beagle2 project team the capability to fully sterilise a wider range of products/materials. 1.3 Limitations

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The drawbacks of the Sterrad system are to do with the physical limitations of a gas/vacuum process and the reactivity of the chemistry. The system is unable to process liquids, powders, sealed chambers or strong absorbers (e.g., cellulosics). Materials which react with the gas may also limit the application (see 4 below and Appendix 1). As a surface sterilant process, hydrogen peroxide gas plasma does not kill embedded organisms or organisms in sealed areas of the instrument (c.f. heat or irradiation technologies). This is important from a COSPAR perspective as embedded spores are still therefore viable and could still be released into the martian environment. As with all the sterilisation technologies, the process kills contaminant organisms, but does not remove them. To meet the particulate cleanliness requirements for Beagle2, the item should first be solvent cleaned/disinfected to remove as many organisms as possible, and then sterilised.

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2 SET UP AND PERFORMANCE OF H2O2 GAS PLASMA STERILISATION OF BEAGLE2 COMPONENTS

The following series of stages is intended to be used as an Operating Procedure for members of the Beagle2 Consortium who want to use H2O2 gas plasma for sterilisation/test sterilisation of spacecraft hardware. 2.1 Check Compatibility One of the characteristics of the hydrogen peroxide gas plasma process is the wide range of materials with which it is compatible. However, there are incompatibilities between the sterilisation method and some materials/components. These typically fall in to one of two categories; those which compromise the efficacy of the sterilisation process and those which degrade the component itself, either in terms of structural integrity or performance. It is essential to check against the existing data (see esp. Appendix 1) before committing valuable hardware to the process. 2.2 Sample Processing A critical approach to compatibility of process and materials is essential for sterilisation technologies. The more complex an item, and by inference the more different types of material are present, the greater the risk of an incompatibility. This may even be due to differences in batches/grades/manufacturers of a given material. The lowest risk approach is to sterilise a completed flight-representative item, expose to a realistic life test and then test performance. However for Beagle2, this is not a viable option for flight hardware due to lack of time. It is important therefore to gain as much information about likely effects as possible before committing flight hardware to the process. The approach should be, after compatibility checking, to test sub-assemblies and then prototypes before testing flight items. 2.3 Check Availability At present time, the Sterile Services Department at Leeds General Infirmary have agreed to give the project free access to their Sterrad unit. They have capacity available and, subject to medical emergencies it is possible to book time in advance. However, the speed of the process means that the longest wait following arrival would be 75minutes. In order to co-ordinate this activity, times should be arranged through the Planetary Protection Manager rather than going direct to the hospital. 2.4 The Pre-process Microbiological Assay Ideally, the item will then be sent/taken for microbiological testing. The test is based around the NASA NHB5340.1B process for monitoring microbiological contamination of space hardware.

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Essentially, a 25cm2 sample area is swabbed and the swab rinsed in microbiological growth media; in the case of detecting heat resistant spores for COSPAR monitoring processes, this is following a “heat shock” procedure, which is selective for only the spores of interest (see also Appendix 3). The number of cells obtained during this procedure can then be related back to the COSPAR requirements and the project-specific requirements in the PPIP. This process takes around 3-4 days before the micro-organisms grow sufficiently to be analysed. 2.5 Packaging and Storage For the Beagle2 hardware items to be sterilised, some will require ESD protection, others not. All will need the sterility of the item to be protected once the Sterrad cycle is finished. As a principle, all items being sterilised must be double wrapped going into the steriliser chamber. This allows the outer layer to be discarded as the item is transferred into the AAF. 2.5.1 For ESD Sensitive Materials iv. Use of grey metallised anti-static materials is preferred to the static-dissipative “pink

poly”. v. Bags should be closed with tape over the end to permit air evacuation and backfill with

H2O2 (the metallised bag is not gas-permeable). Peroxide indicator tape can be used as it is known that this is compatible with the sterilisation process (i.e. the adhesive is not degraded).

vi. An earthing tag of metallised tape should be used to give continuity between the hardware, the metallised bag and the plasma chamber

vii. Closed bags can then be put into single Tyvek pouches and sealed (allowing the earthing tag to protrude). The item to be sterilised is now ready for sterilisation.

2.5.2 For non-ESD sensitive items iv. Whilst any non-sealed packaging layer can be used as the primary packaging, it is

recommended that a Tyvek pouch is used, as this will give a complete microbial barrier when the item is storage.

v. If another bag type is used, it should be closed with tape over the end to permit air evacuation and backfill with H2O2. Peroxide indicator tape can be used as it is known that this is compatible with the sterilisation process (i.e. the adhesive is not degraded).

vi. The item can then be put in a second Tyvek pouch and sealed. The item to be sterilised is now ready for sterilisation.

In the case of items too large for available Tyvek pouches, it is intended to make reel or tray wrap materials available. In this event, the peroxide indicator tape/heat sealing should be used to custom-make a sealed package. 2.6 Inclusion of Biological Indicators

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A biological indicator (or “spore strip”) will be included with each operation of the Sterrad. This is a method of proving the efficacy of the sterilisation cycle without compromising the sterility of the item being processed. Processed at the same time as the spacecraft hardware, the biological indicator contains 106 spores from a resistant bacterial strain. Following exposure to the Sterrad cycle, these are assayed microbiologically. It is usual to find zero growth in the assay, indicating a microbial reduction factor of at least 6logs. (see also 3.2 and Appendices) For practical purposes, this indicates that items manufactured in an uncontrolled environment (i.e. with an initial bioburden of 105 spores/m2) will have zero survivors after the process (post-sterilisation Sterility Assurance Level = 10-1). 2.7 Processing The Sterrad instrument has a standard and an extended sterilisation programme. The standard programme is sufficient for spacecraft hardware sterilisation and should be used to minimise risk of interaction of H2O2 with materials in the instrument. In the case of use of the instrument at Leeds General Infirmary, LGI staff will be responsible for operating the instrument. Staff from Beagle2 consortium members will be responsible for ensuring adequate packaging of the relevant hardware prior to the Sterrad processing and for the safe handling of the hardware itself, including ensuring earth continuity to minimise ESD risk. 2.8 Post process handling Sterility of the item following processing will only be compromised if the packaging is breached and the item is exposed to a non-sterile environment. It is therefore important to minimise the risk of this happening. Double bagging should be retained if an item is outside a clean area (this may mean rebagging if an item is required to leave a cleanroom and then come back). Sub-contractors and other workers need to be made aware of the need to retain sterility of items post-processing, particularly if working outside a cleanroom (e.g. at a test house). 2.9 Re-sterilisation Some effects of sterilisation will be cumulative, resulting in increased degradation of performance after numbers of cycles. It is important that re-sterilisation options should be reviewed with the PPM on a case-by-case basis before committing items to further sterilisation.

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3 TEST PROGRAMME TO DATE 3.1 Testing Performed A sample testing programme is underway for Beagle2 hardware intended to be sterilised by hydrogen peroxide gas plasma. Items that have been identified as potentially problematic, which need to be sterilised by this method, or are particularly complex/sensitive have been included. All items were tested for key behavioural characteristics before and after sterilisation. At the present time, none of the test items have become entirely compromised by the process, however chipping of paint has been observed and data is not complete for evaluation of solid sulphite-based lubricants such as WS2 and MoS2: Table 5.1: Effects of Plasma Sterilisation on Materials and Assemblies Item Source Device

Identity Description Tests Result

1 Astrium PPS PPS breadboard Function tested according to Test Procedure BEA2.SP.00014.S.MMS.

No immediate significant change

2 Astrium OP490 Quad op. amp. Each section tested for quiescent current, voltage gain and offset voltage.


3 Astrium AD584 Voltage reference Each of three outputs tested for quiescent current, reference voltage drift.


4 Astrium 4071 Quad “OR” gate Each section tested for quiescent current, function and change-of-state threshold voltage.


5 Astrium LP2951 Linear regulator Tested for quiescent current and load regulation.


6 Astrium IRF530 Power MOSFET Tested for RDSON and conduction threshold Gate-Source voltage.


7 Astrium Li ION Li ION 8.4V battery

Tested for charge/discharge characteristics.


8 LU Microscope LEDs Operational performance No immediate significant change

9 LU MoS2-lubricated Stepper Motor

Operational performance Operates, but casing paint removed during process

10 LU Microscope Adhesive

Appearance No immediate significant change

11 LU Friction test of MoS2-lubricated nut and bolt assy.

Tested “before” and “after” to determine effect of peroxide gas plasma on MoS2


12 OU UV photodiode Basic functional test No immediate significant change

13 OU Photodiode window

Microscopic examination comparing “before” and “after”


14 OU EM dust sensor Full functional test No immediate significant change

15 MSSL DM Camera Functionally tested to generate images


16 Astrium Friction test of MoS2-coated disc

Test “before” and “after” to see effect of gas plasma on MoS2

Data not complete

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3.2 Microbiological Test Results The DM model camera (item 15 in Table 5.1) was additionally subjected to a microbiological analysis. Full details of the pre-sterilisation analysis are given in Appendix 3. In summary, the data indicates a pre-sterilisation bioload of 70,000 spores/m2 as opposed to the COSPAR requirement of 300 spores/m2 at launch. With a surface area of 0.08m2, this represents an absolute bioload of 5600 spores against a requirement of max 24 spores on the item. This highlights the requirements of the project for sterile build in an aseptic facility and for sterilisation processes to be performed on components/systems on the spacecraft. Biological Indicator test data from the spore strip processed in Sterrad cycle #4522 with the DM camera (Appendix 6) indicates no growth. This provides confidence that the camera achieved a level of sterilisation in excess of 6logs.

In absolute terms, this represents a sterility assurance level of 0.0056, or (approximately) a 1/200 chance of a single survivor spore being present after sterilisation.

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4 RECOMMENDATIONS AND ADDITIONAL TESTING REQUIREMENTS

4.1. Use of Hydrogen Peroxide Gas Plasma The hydrogen peroxide gas plasma is an effective method for surface sterilisation and is acceptable for use in the Beagle2 programme. The plasma technology complements other approaches being used in the programme (see Appendices). 4.2 Limitations The plasma technology is not proven for space hardware, in comparison with dry heat where many materials/components are guaranteed to perform after exposure to eat sterilisation temperatures. It should therefore only be used where i) there is not a suitable alternative and ii) test information supports the compatibility of process and materials. 4.3 Additional Testing Additional testing is required to prove compatibility of the process with: Solar cells VDA coating Completion of testing is required for: MoS2 and WS2 lubricants Painted materials This needs to be completed before flight model items can be considered for hydrogen peroxide gas plasma sterilisation.

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Ref: P3450026 Issue: Issue 1.0 Date: 10th June 2005 Page: 77 of 103

APPENDICES APPENDIX 1: H2O2 GAS PLASMA INCOMPATIBILITY CHART Material

Process Incompatibility

Material Incompatibility

Effect

Cellulose (fabric)

Nylon (fabric)

Polyurethane (fabric/foam)

Absorbs gas which compromises efficacy of plasma process, giving incomplete sterilisation (effect depends on the amount of material present)

Copper

Silver

Manganese

Transition elements catalyse decomposition of hydrogen peroxide. Large amounts compromise the sterilisation. Presence in enclosed volumes can cause pressure damage/explosion risk. Not usually a problem for electronics boards

Sulphides (e.g. WS2, MoS2) Risk of decomposition and loss of lubricity

Polyamides inc. adhesives Risk of decomposition and loss of

performance (e.g. adhesion) Paint Chipping, loss of finish

Dyes e.g. loss of colour in cold-anodised

aluminium Time Delay Effect of Inappropriate Sterilisation Technology There is considerable history of failure of materials caused by inappropriate sterilisation processing which only comes to light several months/years after processing. Examples in the medical device industry where sterilisation is used more extensively include 3M knee joints with catastrophic premature wear and Becton Dickinson syringes with “exploding” barrels. In the present case of spacecraft assembly after hydrogen peroxide gas plasma processing, this includes dry solid lubricants, such as molybdenum disulphide, used during component assembly. These lubricants remain in the device and degradation over time could lead to eventual failure. Potentially a long-term, multi-stage mechanism can be initiated where, in the first stage during sterilisation, small amounts of hydrogen peroxide may diffuse into the part and reach the lubricant. The lubricant reacts with the hydrogen peroxide, oxidising the sulphur and leading to sulphuric or sulphurous acidic residue formation. The following stages occur when the acidic residues attack materials, such as plastics and adhesives, from within the device, leading to eventual weakening and premature failure. These mitigate against widespread unmonitored use of the H2O2 gas plasma technology for components where there is any doubt about the effect of the process on the materials present. The approach should be to find an alternative or to prove the compatibility of the process by either real time/representative environment tests or establishment of a space qualified material database. As in the case of Beagle 2, it may be that work can be done to confirm that any degradation, though detectable, is not significant in the context of the specific spacecraft mission.

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Appendix 3: OPEN UNIVERSITY ASEPTIC ASSEMBLY FACILITY SPECIFICATION

CONTENTS 1. Introduction 2. Description of facility 3. Air management 4. Materials used in the facility 5. Thermal loading 6. Mechanical loading 7. Number of personnel in facility 8. Monitoring equipment 9. Waste disposal 10. Services to be provided 11. Health and safety 12. Cleaning and sterilisation facilities 13. Maintenance 14. Cleanliness validation 15. Sterility TABLES Table 1 Thermal loading FIGURES Figure 1 Proposed Aseptic Assembly Facility layout

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1. INTRODUCTION The project requires the construction of a vertical flow clean room including change rooms and preparation areas to facilitate the fabrication of the Lander vehicle, which will undertake experiments attempting to ascertain “Life on Mars”. The construction of the clean room and associated areas shall be such that the inclusion of unwanted matter is minimised and that construction materials do not create a hazard to the experiment. The Lander is to be assembled in aseptic conditions in the Aseptic Assembly Area, and the complex is referred to as the Aseptic Assembly Facility (AAF). The contamination control concept is the shell-like example as shown in ISO/FDIS 14644-4: 2000 (E) – Annex A. All building control applications will be by The Open University. 2. DESCRIPTION OF FACILITY The AAF will consist of a Aseptic assembly area, changing rooms and goods in processing rooms. Entrances to the facility will be via the changing rooms that are designed to allow separate access to the highest levels of clean room operations and preparation area. The facility is designed to have all the equipment and services required to minimise contamination risk to the Lander. In this respect equipment exists for sterilisation of the component parts. Health and Safety is an important consideration with account being taken of the need for containment of hazardous materials in the event of accidents in the area. In general the clean room will conform to BS EN ISO 14644 and British Standard 5295 (1989) An initial schematic layout of the area is shown in Fig 1. 2.1. General The Aseptic Assembly Area, together with the rest of the facility i.e. goods in and changing rooms, will have filtered airflow delivered through ceiling mounted terminal HEPA filters and extracted through wall/door grilles. In the central Aseptic area, filters will be located such that the protection afforded to the Lander assembly is maximised A cascading pressure gradient will be maintained throughout the facility, with the Aseptic Assembly area at the highest pressure. 2.2. Outer changing room The changing rooms are unisex and will be equipped with interlocking swipe card, access control doors by Maglox/Expert Security or equivalent that will act both as a security and privacy control system. The outer changing room enables removal of outer clothing including shoes and socks. Sterilised socks, captive shoes and undergarments are put on at this stage before entering into the final changing area. This area will be equipped with a disinfectant dispenser for washing of hands

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2.3. Final dressing room This stage is followed by the final dress stage. All changing rooms will be supplied with filtered air, supplied through ceiling mounted terminal HEPA filters and extracted through wall mounted grilles. This area will be equipped with an alcohol dispenser for washing of gloved hands. Separate accesses are provided from here into to the Aseptic assembly area and the primary preparation area. 2.4. Goods in (Preparation) air lock Equipment will enter the facility via a goods inward air lock. The doors into and out of the air lock will have Maglox access or equivalent and interlocking traffic lights complete with alarm systems to prevent both from being opened at the same time. The width of all access doors will be a minimum of 2000 wide (tbd) x 2150mm high. Large equipment such as Mechanical Ground Support Equipment (MGSE) will be cleaned in this area. The air from this area will be exhausted to atmosphere. 2.5. Primary preparation area This area will house the sterilisation ovens. It will be used to ensure components are correctly prepared and processed prior to entering the central area. A pass through box will be provided into the central area. Potentially, sterilisation equipment will be of the through the wall design. 2.6. Aseptic assembly area This area is at the highest level of control. ISO Class 4 or better at rest and ISO Class 5 in normal operation, the filters will be immediately above the lander work area. Lighting will be maintained at a high level. During quiet hours, normal lighting will be replaced by a uv lighting by a toggle switch, protecting the immediate zone around the lander. 2.7. Entry and evacuation routes Entry and exits are shown against the appropriate doors on the accompanying drawings 2.8. Supporting equipments The facility will include provisions for equipment needed to support the manufacture and test of the Lander. This will include BOFA recirculating filtered exhaust cupboard for epoxy mixing Ultra sonic cleaning equipment Vacuum Oven Drying Oven These units will require power and associated extract/vacuum systems.

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Figure 1 Proposed Aseptic Assembly Facility layout (shaded area = siting of filter banks) (main class 100 area is 7m by 5m approx)

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3. AIR MANAGEMENT 3.1. Air Management Air management will be in two parts: i) that which supplies clean air to the final assembly areas and ii) that which manages the supplies, and extraction to the changing rooms and goods in processing rooms. In the event of an emergency such as fire or an accident involving radioactive leakage, all the air handling systems will be shut down automatically and/or by manual override buttons located in designated positions such as the assembly areas. The air and air management systems shall be designed to provide where possible maximum redundancy capability. Details of this shall be included in the proposal. 3.2. Air Pressure The AAF will at all times have a pressure greater than ambient conditions and is maintained at a positive pressure gradient to surrounding/support areas. 3.3. Air conditioning/Temperature The temperature in the AAF area will be capable of being controlled to a set point temperature between 17C and 20C +/- 1C 3.4. Humidity The humidity within the AAF area will be maintained at 50% RH +/- 5% 3.5. Filtration Filtration within the AAF will be maintained at 99.9998 % at 0.12 microns or better and operate at ISO Class 4 or better at rest and ISO Class 5 in normal operation (ie with 4 operators present in the Aseptic assembly area). The filter housing is to be manufactured from stainless steel. 3.6. Chemical filtration The entire fresh air intake will be provided with molecular filters for removal of airborne molecular contamination. It may be a requirement that the AAF will also have molecular filters provided as part of the internal air circulation. 3.7. Fresh air changes The introduction of fresh air should be minimised whilst meeting the requirements of pressurisation, removal of solvents used in cleaning and number of operators using the area. 3.8. Air Changes to the AAF The air changes will be of the order 130/hr with 90% recirculation (10% fresh air make-up) at each pass. 3.9. Electrical test set area

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All electrical test sets are required to be located outside of the Class 4 area and will have separate air conditioning in order to dissipate heat from test equipments. See table 1 for heat dissipation levels. Particulate cleanliness is not required in this area. 3.10 Fire suppression No fire suppression equipment will be fitted in the clean room and changing room complex. 3.11 Fire detection The complex will be fitted with an independent fire detection system, manufactured by Thorn/Gent. This will be repeated to the main Open University panel. A separate cost should be shown for installing a VESDA (very early smoke detection system) in the AAF. 4. MATERIALS TO BE USED IN FACILITY Materials to be used for the internal construction of the facility will be confined where ever economically possible to stainless steel and glass and be compatible with disinfectant. The use of hydrocarbon based materials such as plastics and paints will be minimised unless with the agreement of the OU. All materials and amounts will be declared and approved by the OU. 4.1 Door furniture All door furniture/locks to be Wadsworth – chorus locks – suit numbers to be provided by The Open University. 5. THERMAL LOADING Air conditioning calculations and electrical loading should be submitted as part of the tender Additional thermal loading will come from personnel and various test and sterilisation equipments as shown in the Table 1

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Table 1 Thermal loading

EQUIPMENT INSIDE AAF – KW

OUTSIDE AAF – KW

REMARKS

Electrical test equipment 3 – used continuously

Will be located outside of AAF

Ultrasonic cleaning 3 - infrequent operation

Will be in a room within the AAF

Gas plasma sterilisation 4 - 1 hour operation – infrequent use

May be in a room within the AAF

Autoclave dry gas sterilisation ovens (2)

15 -frequent/ continuous use

Will be in a room within the AAF

PC 0.35 2 key boards and mouse inside AAF and server and monitor outside

Other test equipment 0.5 Contingency 2.5 2.65 TOTAL PEAK 25 6 TOTAL AVERAGE DISSIPATION

15 6

6. MECHANICAL LOADING The maximum single mechanical load on the floor of the AAF will be 500kg distributed over an area of 2.4 m2. The maximum point load will be 500kg. In the final assembly areas (5m x 7m) the maximum load will be 500kg plus 6 people at a total of 600kg. Possible provision of a 200kg-lifting eye in the AAF ceiling is to be determined. 7. NUMBER OF PERSONNEL IN AAF Whilst the number of personnel working in the AAF will be kept to a minimum, the maximum number at peak activities will not exceed 15 people. Under normal conditions it is expected that no more than 4 people will be working in the ISO Class 4 Aseptic assembly area. 8. MONITORING EQUIPMENT The facility will be equipped with fully validated PC based monitoring system for: • Humidity • Pressure • Temperature • Airborne particulate contamination Additional monitoring capabilities may be required on a continuous or systematic basis: • Monitoring of hydrocarbon air-borne materials • Radioactivity (portable and free issued)

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Microbiological monitoring will be carried out on a routine basis. This will not be provided by the facility sub contractor. A CCTV system supplied by Weston Imaging (or others) may also be required in the build area to monitor build and test. All monitoring will be available over the Astrium intranet. Audio/visual facility (to be designated) for communications with operators without requiring them to leave the facility are needed. 9. WASTE DISPOSAL Dry waste disposal facilities will be provided in the outer changing room and also the primary preparation areas. 10. SERVICES TO BE PROVIDED 10.1 Power supplies All power supplies will require earth leakage trips. The assembly work area will have 6 off twin 240v 13 amp mains sockets. Mains power supplies will also be supplied in the goods in and preparation room. A minimum of 2 x twin points shall be provided for each room. A 3 phase supply 415V, 50Hz, 10amp may be needed in the preparation room for the Gas Plasma steriliser, if fitted. A 20-amp supply and start capability from within the Aseptic area are required for a high vacuum pump to be located outside the Aseptic area adjacent to the test instrument area. 10.2 Back up power supplies All power fail supplies to equipment to be via single on line UPS units supplied as required by the Open University. A 200A change over switch facility is required to enable all alternative power sources during the testing period. Standard 3 hour maintained lighting will be required after power failure. 10.3 Electrical interfaces for data installation Interfaces with test equipment will be by a PC keyboard and mouse located in the Aseptic assembly area. The main test equipment will be located outside of the Aseptic assembly area, but with switch controls accessible from within the Aseptic assembly area eg via glove ports. It is also envisaged that there may need to be other test aids such oscilloscopes used in the Aseptic assembly area and in which cases provision will be provided for mains sockets built into the facility.

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All wiring will be CAT 5 UTP to be run in radial circuits back a reception area (tbd). The following dual sockets will be fitted: Goods in 1 Primary preparation 4 Plant room (tbd) 2 Main AAF 16 Outer change 1 Provision is to be made for a 6U cabinet (wall mounted) and a 64-way patch panel. All cables are to be terminated and left in the patch panel for connection to OU interface by the OU. 10.4 Electrical Ground Support Equipment (EGSE) Test Set All test equipment will be housed in an enclosed room with access from outside of the Aseptic assembly area. All connections to the test article in the Class 4 area will be via a PC keyboard inside the Aseptic assembly area. Provision will be made to enable manual operation of test set controls through the dividing glass partition between the Aseptic assembly area and the test instrument area. Access to the test equipment will be by means of test cables from Lander via access ports to the test set and through CAT 5 connections located in the interface wall for PC network connections. To facilitate other test aids, glove ports and adjustments will be provided in the test set room wall to enable manual control of equipments. Doors will be provided to enable access from the office area and also from the rear via the roller doors to enable installation and removal of test equipment. 10.5. Audio / Video Monitoring Audio/video monitoring will be provided in the main assembly areas to enable communications with engineering teams at Astrium, Martin Baker, Leicester University and Open University. Facilities will be provided to enable communications through the interface walls. These will be compatible with the need for biological isolation of the two rooms. (Equipment to be designated) 10.6. Cameras and speakers Provision should be made for installing 4 off CCTV cameras, and connections for a mobile hand held video camera, suited for fine detail observation. All cameras to have the ability to record in digital format (tbd). Cameras to have microphones incorporated to external based PC speaker. Speakers/microphones between Aseptic assembly area and test area to be provided (tbd). 10.7. Electrical bonding It is a requirement that the floor of the Aseptic facility will be of an antistatic type. In the Aseptic assembly area provision, will be made for bonding of the MGSE to the floor structure. Earthing will be required to enable personnel and equipments to be earthed. The start point for the earth connection will be located as close as possible to the test set. Bonding resistance and clean earth requirements to be advised by Astrium.

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10.8. Vacuum lines a) Each area will require vacuum cleaning capability. This may be through an built in integral system (tbd). b) The final assembly area will require adjustable extraction for local activities such as during soldering etc. The Aseptic assembly area will be provided with 4 vacuum extract connections. c) A high vacuum line and flange connection will be required into the final assembly area. Note: vacuum lines are to be trapped to avoid any back streaming of any possible molecular or carbon contamination. 10.9. Clean air purge line filter/assembly Two connectors will be provided in the assembly areas to enable clean air / nitrogen purge supply to be linked to the flight assemblies. Astrium to designate flow rates and connections required. 10.10. Vision panels Vision panels are to be provided where possible around the work area to enable processes to be overseen without entry. They will be required on the separating wall between the instrumentation area and the Aseptic assembly area. Viewing is also required from the office area (tbd). The glazing shall be clear laminate safety glass with the installation of the window(s) maintaining a half hour fire rating. 10.11. Roller shutter doors The roller shutter doors are to be provided with high leak drip/catchment trays with low-level collection to prevent oil spillage. 11. HEALTH AND SAFETY The design of the AAF should also take account of hazardous materials and operations. The Lander will at various stages of build be equipped with radioactive isotopes, beryllium components, ammonia gas generators and pyrotechnic devices. In the unlikely event of an explosion the facility will need to evacuate and containment of radioactive particles be achieved. All air handling will be required to shut down in such an eventuality. Provisions will be made for fire control in the facility – no fire suppression or sprinkler system will be permitted. Provision will be made for identifying any maintenance requirements and associated necessary equipment

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12. CLEANING / STERILISING FACILITIES Included in the AAF will be a cleaning facility consisting of an ultra-sonic cleaner, a gas plasma steriliser and two ovens. 13. MAINTENANCE The maintenance programme for maintaining cleanliness of the AAF shall be proposed by the supplier 14. CLEANLINESS VALIDATION The AAF will be commissioned to the cleanliness requirements of BS EN ISO 14644 – ISO Class 4. Chemical cleanliness will be monitored (tbd), ideally on a continuous basis. 15. STERILITY The Contractor will be responsible for commissioning the area for sterility after which specialist sub contractors will carry out all day to day sterility validation work

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Appendix 4 BEAGLE 2 CLEANROOM OPERATORS TRAINING PROGRAMME

Day 1: Beagle 2 and Planetary Protection

• Programme Introduction • Planetary Protection Overview (course overview and relevance to Beagle2) • Mission Science Requirements (cleanliness requirements for the Gas Analysis Package) • Introduction to Microbiology (the microbiological world and relevance to spacecraft

assembly) • Microbiology Workshop (a live microbiology session)

Day 2: Beagle2 Aseptic Assembly Facility (AAF) Design and Operation Strategies • Sterile Facility Design Strategy (Considerations in the design and construction of the Beagle2

AAF) • Work Flow and Process Control (AIV work flow in the AAF) • Minimising the Impact of People (Occupational health input to managing contamination risk) • Facility Monitoring (Microbiological, Chemical and Particulate monitoring in the AAF) • Cleanroom Clothing/Gowning (Theory and practice of garment design and usage) • Course Review

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Appendix 5 OVERVIEW OF CLEANROOM WORK DISCIPLINES FOR

BEAGLE 2

If in doubt, ask!

1 INTRODUCTION Beagle2 is the lander component of the European Space Agency’s Mars Express Mission.

Amongst other experiments, the Beagle2 lander will search for five criteria which

demonstrate that life processes could have operated in the past on Mars. These analyses

require that no living terrestrial microbial contaminants, or debris from living organisms or

other organic sources, which could potentially corrupt the scientific data, are carried on the

spacecraft. Cleanroom assembly in the Beagle2 AAF under stringent cleanroom conditions,

is one of several approaches being employed in the spacecraft manufacture, as identified in

the PPIP (BGL2-OU-PL-007), to ensure the spacecraft meets this element of the

specification.

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2 SCOPE This document is intended to be an introduction to the more detailed operating procedures for

cleanroom working in the Beagle2 AAF. It is written in five sections, giving overviews of:

• Staff responsibilities.

• Changing procedures for cleanroom entry and exit.

• Cleanroom Disciplines.

• Cleanroom Monitoring

• Introduction of tools, MGSE, EGSE and spacecraft hardware into the facility.

It is intended that all staff operating in the cleanroom should be familiar with this and other

documents relevant to their own specific tasks/roles.

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3 STAFF RESPONSIBILITIES People are the source of practically all of the microbes in a cleanroom and a major source of

particles. To prevent contamination of products manufactured in cleanrooms, disciplines must

be used to minimize the generation, transfer and deposition of these contaminants. These

disciplines are discussed in this document.

Products manufactured in cleanrooms vary in their sensitivity to contamination and,

generally, contamination control methods will reflect this.

NB Beagle2 represents a special and extreme case: the target is zero contamination, and

hence the control disciplines are very stringent and MUST BE ADHERED TO.

Before being permitted to work in the cleanroom by the Planetary Protection Manager (or his

nominee), every individual will have to undergo a course of appropriate training.

On a day to day basis, every cleanroom worker is held personally responsible for ensuring

they are in compliance with the requirements for cleanroom working as detailed in this and

other relevant documents.

NB Entering the cleanroom is taken as a de facto acceptance of these requirements by the

individual.

In addition to the normal conditions of work in spacecraft assembly/manufacture, working in

the cleanroom areas of the Beagle2 Aseptic Assembly Facility (AAF) imposes additional

requirements for cleanroom working. These are given below:

1. Staff must become comfortable with (a) wearing garments which will cover essentially

all of their body and (b) working in a room which has no natural lighting or windows.

2. Staff must understand that wearing cosmetics, talcum powder, hair sprays or similar

materials into cleanrooms is not allowed. Anything added to the body is a potential

contaminant and must not be worn.

3. Staff must not wear nail polish as it may chip off and get into the product.

4. Smoking is actively discouraged. It has been demonstrated that smokers produce

more particles from their mouth, after smoking, because the lining of the mouth will

dry and emit more particles. Smokers who must work on the project will not be

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permitted in the cleanroom until half an hour after their last cigarette and must drink

a glass of water before entering the change area.

5. Individuals working in the cleanroom should shower or bathe daily to maintain

personal hygiene at a level compatible with cleanroom working. Similarly, garments

worn under cleanroom garments e.g. underwear should be laundered with

appropriate frequency. Common sense should be used, fresh daily is good practice.

6. Make-up is not allowed in the cleanroom. Personnel should consider whether

applying cosmetics is necessary, as they will be required to remove them prior to

going into the cleanroom. They should also consider what rings, watches and

valuables they will carry, as they will have to be removed and stored.

7. It is not be prudent for people who disperse significantly greater amounts of

contamination (e.g. through skin shedding) than the normal population to work in the

cleanroom. Examples are those who have skin conditions or chronic coughing. In the

event that such an individual must be used, then medical intervention will be sought to

reduce the contamination risk.

8. It is necessary to screen cleanroom personnel to determine microbiological status

with regard to section 7 above.

9. People with temporary ailments such as a cold, flu, sunburn, bad dandruff, dermatitis,

as well as any allergy that will cause them to cough, sneeze, or their nose to run, are

be best employed, during their time of incapacity, outside the cleanroom. These

conditions should be reported on arriving at work.

10. People suffering from chronic allergic conditions which cause sneezing, itching,

scratching or a running nose may not be suitable for cleanroom working. In

particular, some people may be allergic or react to items used in the cleanroom, such

as (a) garments made from polyester, (b) chemicals such as solvents and cleaning

agents. In contrast, some sufferers from hay fever will find relief in the cleanroom,

because the air filtration system will filter off the responsible allergens; after a time in

the change area for their symptoms to be relieved, they may be able to commence

working.

Before entering the change area personnel should, if necessary, go to the toilet. This will

minimise the difficulty of garment changing and the time wasted by having to leave the

cleanroom. If required, they should blow their nose.

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4. ENTRY AND EXIT CHANGING PROCEDURES

Correct changing procedures will ensure that garments worn in the cleanroom are not

contaminated. There are several ways of correctly putting on cleanroom clothing, but the

Beagle2 programme is standardising using the method described in document BGL2-OU-

AAF-GOWN.

The Beagle2 Change area has three zones of increasing cleanliness level, isolated from each

other by barriers and stepover benches. Protocols defining the gowning process (where

outdoor and cleanroom clothing and footwear are taken off, and put on, etc. and which

garments are used) are given in document BGL2-OU-AAF-GOWN. Which protocol is used is

dependent on the task and area of the AAF in which the individual needs to work.

An outline of the gowning method for entry into the Aseptic Assembly Area is included for

information, as follows:

(in Primary Change Area)

1. Remove shoes and store in locker.

2. Remove street garments and store in locker.

3. Put on cleanroom undergarments.

4. Remove watches, jewellery, mobile phones etc and store in locker, remove or cover

rings.

5. Whilst putting on cleanroom-dedicated under-shoes…

6. Cross stepover bench into intermediate change.

(in Intermediate Change Area)

7. Wash hands at automatic dispenser.

8. Put on gowning gloves.

9. Wash gloves at automatic dispenser.

10. Pick out garments.

11. Put on hood.

12. Put on coverall.

13. Whilst putting on overshoes…

14. Cross stepover bench into final change.

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(in Final Change Area)

15. Check dress for correctness in mirror.

16. Put on mask or mask+safety goggles as appropriate.

17. Put on sterile gloves, discarding gowning gloves.

18. Check ESD continuity using wall box and footplate.

19. Wash gloves at automatic dispenser.

20. Stand for 1 minute with arms raised under the air shower.

21. Enter Aseptic Assembly Area.

Exit is essentially a reverse passage through the change procedure, discarding disposable

items to waste and recycling laundry items as described in the detailed protocols.

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5. CLEANROOM DISCIPLINES

Within any cleanroom, many disciplines must be followed to ensure that the product is not

contaminated. These general guidelines are adapted to reflect the particular needs of

Beagle2:

• Only essential personnel should be allowed in the cleanroom. The more people in a

cleanroom the higher the contamination level.

• Only people who have been trained to work in a cleanroom, and fully understand the

procedures used, should enter the room. Visiting workers will only be allowed to work

after appropriate training and under the control of a supervisor experienced in

cleanroom working.

• Personnel must not take contaminating materials into the cleanroom. In general, only

work items should be allowed into the cleanroom and these should be of a type that

will not contaminate the room. A selection of prohibited items is as follows:

1. Food, drink, sweets and chewing gum.

2. Cans, aerosols or bottles.

3. Smoking materials.

4. Radios, CD players, Walkmans, mobile phones etc.

5. Abrasives or powders.

6. Items made from wood, rubber, paper, leather, cotton and other naturally occurring

materials. The need for paper is eliminated by the provision of computer facilities in

the aseptic area.

7. Newspapers, magazines, books and paper handkerchiefs should not be brought in.

8. Wallets, purses, spectacle cases and other similar items.

9. Pencils and erasers.

10. Other writing implements that could scratch surfaces or whose ink contains

contaminating chemicals.

11. Other unauthorised chemicals eg correcting fluid, detergents.

• Doors should not be left open or there will be a loss of pressure and undesirable

movement of air between areas.

• Doors should not be opened and closed quickly, This will increase the amount of air

transfer between areas. Doors are fitted with door-closing devices to ensure their

slower movement and positive closing.

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• When passing through one set of doors into an airlock, personnel should wait until the

first door is closed before going on into the next one. Interlocking devices fitted to

door fastenings are fitted to facilitate this.

• Personnel must always come in and out of the cleanroom by change areas. The

change area is used not only to change clothing but as a buffer zone between the dirty

outer corridor and the inner clean production area. Personnel should not use the

goods in entrance, which leads from the production area to uncontrolled

environments, as this will let contamination directly into the cleanroom and garments

will also become contaminated.

• The room should be kept neat and tidy. A cleanroom cannot be kept clean if it is

untidy.

• Personnel should be positioned correctly with respect to the product. They should not

lean over the product in such a way that particles or bacteria fall from the garment, or

pass out from the garment openings and fall on the product. Personnel should make

sure that they are not between the product and the source of the clean air i.e. the air

filter, or a shower of particles could deposit on the product. The method of working

should be pre-planned to minimize contamination.

• Consideration must be given as to how products are to be moved or manipulated.

Items must be carried and placed in position, rather than thrown or dropped.

Methods based on ‘no-touch’ techniques should be devised for each operation. These

techniques were originally devised by the medical and microbiological professions to

manipulate sterile products in such a way that they would not be contaminated by the

bacteria from their ungloved hands. Although gloves are worn in cleanrooms, they are

still likely to be a source of contamination (although a reduced one), and similar

techniques should be used. Examples of this are the use of vacuum wands and forceps

to pick up items.

• Personnel should not support material against their body when they are carrying it

around a room e.g. carrying an item under their arm. It may be assumed that the

outside of the cleanroom garment (although much cleaner than normal clothing) will

have particles, fibres and bacteria on its surface. These will be transferred onto the

items being carried.

• Personnel should never talk when they are working over the product. This is a clear

necessity if a face mask is not used. However, if a face mask is used, mouth and nose

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secretions can by-pass round the outside of the mask, or the high pressure generated

by a cough or sneeze can push liquid particles off a wet mask and hence contaminate

the product. If personnel must cough or sneeze, they must turn their head away from

the product. Masks are normally replaced after sneezing. Masks must not be worn

below the nose.

• Do not allow anything to trail over the product and contaminate it. For example

vacuum hoses, electrical power leads

• It is generally not good practice to touch cleanroom surfaces. Although cleanroom air

is clean, its work surfaces, walls, doors and surfaces of the machinery in the room,

will (potentially) have particles and bacteria on them. Also, if personnel touch their

garments or mask, they will pick up contamination on their gloves, which may be

transferred to the product. Hands grasped together in front of the personnel in the

style of a hospital surgeon will help to ensure that they do not touch surfaces.

• Washing of gloves should be performed. Hand washing facilities for washing gloved

and ungloved hands in water-free alcohol-based antibacterial liquids are provided.

These should be used when entering the cleanroom, after donning gloves, prior to

critical operations in the cleanroom, and after touching contaminated items/surfaces.

• Depending on the application, a cleanroom wipe should be used once, or a

predetermined number of times, and then discarded. It should not be laid down,

between uses, on a contaminated surface, or contamination will be transferred from

the surface to the product. Wiping should be done using overlapping passes. A

dampened wipe is usually more effective than a dry one.

• Silly behaviour is not permitted. The rate of airborne dispersion of bacteria and

particles in a cleanroom is directly proportional to the activity of personnel.

Personnel should walk at a steady pace and their activity should not be boisterous.

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6. CLEANROOM MONITORING Monitoring of cleanroom performance is an essential part of the Aseptic build of Beagle2,

with the following roles:

• Protection of the integrity of Beagle2, confirming the suitability of the build environment

and acting as an early warning indicator of adverse changes.

• As a PP management diagnostic aid in identification, correction and confirming

corrective action for fault (contamination) conditions.

• As a tool to inform the PP status of the spacecraft, with regard to COSPAR reporting.

Monitoring Systems in the AAF include capability for monitoring of:

• Environmental conditions, including; Temperature (set at 18.5°C for worker comfort),

Relative humidity (controlled at 50% for explosive safety) and Pressure (to maintain room

pressure gradients).

• Particulate levels, to make sure working practices are not degrading cleanliness of the

rooms or the spacecraft.

• Visual operations, via the glass screen and intercom, plus the camera, to monitor and

identify for potential contamination events.

• ESD, to ensure gowned workers are at the same PD as the workbench/room/spacecraft to

prevent static generation and damage

• Microbial levels for PP and scientific requirements of the mission.

• Chemical composition of the room atmosphere, to limit the risk of atmospheric

contaminants finding their way onto the lander surfaces

Microbial Monitoring in the AAF includes environmental sampling, to assist in the

management of cleanroom cleanliness and working practices, and hardware sampling to

confirm compliance with COSPAR and Science requirements. This includes:

• Monitoring to support Class 10 cleanroom cleanliness levels

• External validation of approach and NASA-derived protocols for hardware sampling

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7. INTRODUCTION OF TOOLS AND HARDWARE INTO THE FACILITY All items introduced into the facility must be cleaned and/or sterilised according to

cleanliness level on arrival and intended usage within the facility.

All tools, flight and non-flight hardware must be brought into the facility via the Goods-In

entrance, not via the Change area, to facilitate inventory and stock flow control.

Multiple bagging should be used wherever possible to expedite storage on site and/or

transition through the different cleanroom areas.

Cleaning and sterilisation capabilities within the facility includes:

• low level aqueous clean with scrubbing/vacuum as required

• wipe clean with Class 10 cleanroom wipes saturated with IPA (70% Isopropanol,

30% USP sterile water)

• sonic clean in aqueous matrix

• sonic clean in IPA matrix (small components only)

• vapour reflux in IPA (GAP components only)

• dry heat sterilisation at 125°C and controlled humidity

• dry heat sterilisation at 180°C and ambient pressure

• (off site) hydrogen peroxide gas plasma sterilisation

• bagging capability in Tyvek, foil and ESD plastic materials for storage and

transport

Author: ………………………………………. (J A Spry) Date of this version: …………6.9.2002………………. END

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Appendix 6 CLEANING RECORD SHEET Aseptic Assembly Facility

Daily Cleaning Tasks

Date:

Shift Cleaning Shift 1 Shift 2 Shift 3 AAA

Workstation surfaces Stool’s surfaces Equipment Keyboards, touchpads & their tables Door to Change Room Green knob ESD test station, soap dispenser Remove tool trays, tools, solder sponges etc

Final Change Area Door Light switches and green knob Stepover bench surface ESD test station

Daily Cleaning AAA Soap dispenser Table surfaces Outer Change Area Test equipment trolley Empty waste bin Wall by door to Change Area Vacuum & mop floor with IPA Door to Final Prep Room Change solder sponges Final Prep. Room Exposed surfaces on shelves &

tables

Final Change Area Doors (into AAA) Base panel of door Equipment Wall by door & soap dispenser Stool seat surfaces Floor OR shoe compartments & back of stepover bench

Vacuum floor

Hand rail & panels Primary Prep. Room Tacky mat Intermediate Change Door to Final Prep Room Vacuum floor Inner & outer sides of door to

goods in

IPA-clean tiles near bench Work surfaces & window sill Clothes rail & coat hangers Nitrogen oven & handle Door to Final Prep Room Equipment Changing bench surface Empty waste bin Glove dispensers Change water in ultrasonic bath

if necessary

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Aseptic Assembly Facility Week beginning Sunday

Weekly Cleaning Tasks

AAA Undersides of workstations & tables

Final Prep. Room

Undersides of stools External surfaces of balancing rig & control panel

Shelves & Storage bags Doors to AAA MGSE Doors to Primary Prep Room Lower parts of ridged pipe, cables, workstation feet

Door to Change Room

Trolley Final Change Area Pallet Truck Door & door surround Tool bins Back of lockers & mirror Undersides of stools Intermediate Change Door, base panel, door surround Primary Prep. Room Wall next to clothes rail Nitrogen oven Mirror Doors surrounds (Final Prep

Room)

Shoe compartments & sides of bench

Vacuum & mop floor

Stool Outer Change Area Side of bench Barrier/panel Litter bin Laundry stand Tops of lockers

Periodic Cleaning Tasks

AAA Final Prep. Room Baldrick, B’s interface & B’s table

Internal surfaces of balancing rig

Stairs Primary Prep. Room Inside of Nitrogen oven

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Appendix 7 ENVIRONMENTAL MONITORING MICROBIOLOGY RECORD SHEET

Sampling date

Sample No. Air monitoring P.cfu/m³

Settle plates cfu/4hr

Contact plates cfu/plate

Swabs

TSA SDA TSA SDA TSA SDA TVC/swab TASC/swab Swabs 20/11/02 2 20/11/02 3 20/11/02 4 20/11/02 5 20/11/02 6 20/11/02 7 20/11/02 8 20/11/02 9

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