on station 5 - esa

Directorate of Manned Spaceflight and MicrogravityDirection des Vols Habité et la Microgravité

on stationin this issue

Planning the Future: A Year for

Major Exploitation and

Commercialisation Decisions

Jörg Feustel-Büechl

The Crew Return Vehicle 4

Eckart Graf

DMS-R in Control 8

Daniel Guyomard

Transmitting from Space: 10

The Global Transmission Services

Experiment

Jens D. Schiemann

Bridging the Gap 14

ESA’s Microgravity Research

Aboard STS-107

Werner Riesselmann

Station Update 18

News 22

Mission Accomplished 25

Final Report on the Atmospheric

Reentry Demonstrator

Mike Steinkopf

The Newsletter of the Directorate of Manned Spaceflight and Microgravity

number 5, march 2001

foreword

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recent & relevant

dms-r

Last year went superbly well: eight launches to theInternational Space Station delivered long-awaited hardwareand supplies. The hardware elements included Europe’s firstcontribution, the DMS-R data management system, which isworking well. We also had the first Expedition crew onboard –a real milestone for the Station and our overall partnership.The second crew recently took over the reins. I have firmhopes that this year will be as good as 2000.

There are up to 14 launches planned for this year,including some important European contributions.Destiny’s appearance in February was a milestonein the Station’s assemblybecause we now havethe first real operationallaboratory. Although itis not yet equippedwith research facilities, it will be overthe next few months. This means that a goodportion of the infrastructure is now in space, and weexpect that European investigators will soon be ableto perform experiments onboard.

The most recent manned mission delivered the first MPLM,Leonardo, in March. Then, in April, we will have the firstEuropean – ESA Astronaut Umberto Guidoni - aboard theStation, along with the second MPLM, Raffaello. This year’shighly ambitious schedule includes our second Europeanastronaut, Claudie André-Deshays, who is manifested aboarda Soyuz taxi flight in October.

In a more ‘earthly’ sense, we completed the preliminarydesign review of our Automated Transfer Vehicle (ATV) on14 December last year, and that was a technical success. Wenow have a consolidated design but are struggling with thefinancial consequences. On 18 January, the Columbus criticaldesign review concluded – altogether very successful. We arenow firmly on track with Columbus.

PPlanning the Flanning the Futuruture:e: A A YYear fear for Mor Major ajor

EExploitaxploitation and Ction and Commerommercialisacialisation Dtion Decisionsecisions

Jörg Feustel-BüechlESA Director of Manned Spaceflight and Microgravity

http://www.estec.esa.nl/spaceflight/

BERLIN5 - 7 June 2001

ISS UTILISATIONCONFERENCE ON:

RESEARCH AND DEVELOPMENT

INDUSTRIALAPPLICATIONS

COMMERCIALUTILISATION

ISS is a programme ofpartnership

NATIONAL SPACE DEVELOPMENT AGENCY OF JAPAN

The International Space Stationhas established a newpermanent human presence inspace. With the arrival of itsfirst research module, the ISSis now open for exploiting theassets offerred by mannedspaceflight.

In June, ISS FORUM 2001 willtake place in Berlin to reviewthe plans for exploiting the ISSand to brief everyoneinterested in the opportunitiesbeing opened up by this newinfrastructure in space.

The European Space Agency– as one of the five Partners(NASA, Rosaviakosmos, ESA,NASDA, CSA) developing theSpace Station – and theGerman Space Agency (DLR)invite all interested parties to this key event.

The ISS FORUM 2001 programme is supported by allthe ISS Partners. It is designedso that participants fromdifferent sectors:

• understand the Station’sunique potential

• capture available opportunities

• forge alliances for exploiting this new base in space

INTERNATIONAL SPACE STATION

Honorary Programme Committee:

Dan Goldin NASA AdministratorYuri Koptev Director General

RosaviakosmosAntonio Rodotà Director General ESAMac Evans President CSAShuichiro Yamanouchi President NASDAWalter Kröll President DLR

The conference fee is EUR 300 /DM 600

The conference is supported byLufthansa. Special fares to theconference on Lufthansa flightsare available with the codeGGAIRLHKONG.450

Check the website athttp://www.ISSForum2001.comfor further information and to register.

Presentations for this conference are by invitation only.

Questions and comments on the conference can also beaddressed to

[email protected]

The conference is jointly organised and sponsored by ESA and DLR

ISS

FORU

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on Station no. 5, march 2001

practicable and withacceptable costs. Theseneed to be elaborated as one ofthe initial promotional elements ofForum 2001. We must activelypromote our projects in order todemonstrate to investors andindustry that the Station is aworthwhile commercial venture.

We should not forget that around two-thirds of the utilisation remains institutionaland therefore available for scientific researcheither from ESA or our Member States. This isand will remain the backbone of our ISSutilisation programme. And there we have anumber of early projects, including the ACESatomic clock experiment, solar science, Earthobservation and technology experiments thatare under development and that illustrate thescientific and technological utilisation in thebroadest sense as well as being goodopportunities onboard the Station.

We are looking forward to the STS-107Spacehab mission where we have a lot ofexperiments totalling 580 kg onboard. Wehope that it will be launched in September.STS-107 really is one of our key microgravityevents this year. NASA aims to provide oneShuttle research mission per year tocomplement the Station, so we can expect

further such scientific missions. We are keenfor our microgravity community to use

these flight opportunities and havealready made some preliminary

arrangements with NASA for thenext opportunity.

ESA’s DMS-R has been workingfine since its launch last July. We certainlycongratulate the industrial and ESA teams fortheir performance! I would also like to remindreaders that this is an excellent example ofEuro-Russo cooperation, and has turned out tobe of great satisfaction for both parties.

As far as the Station’s Crew Return Vehicle(CRV) is concerned, ESA is currently awaitingan industrial proposal for Phase 1, expected tobe headed-up by a joint team from twoindustrial partners to lead the whole CRVindustrial consortium. We are looking forwardto placing a contract very soon, so that theimplementation can begin in earnest. �

foreword

Of course, one of the significant highlightsof 2001 is the Ministerial meeting inNovember. We are busy preparing decisions forthe so-called Period 1 of the ISS Exploitation.This period covers the 5-year timeframe of2002-2006, with approval of the first 3-yearfirm envelope and the following 2-yearprovisional envelope to be addressed. That willbe a significant topic on the Ministerialagenda. In that context, we will have not onlyimportant decisions on operation of theStation, but also on its utilisation, andparticularly on further efforts to promotecommercial utilisation. We are preparing topromote commercial utilisation with a view toselecting a ‘Business Developer’ to take care ofaround a third of the European utilisation thathas been earmarked for commercialapplications. The other two-thirds are forinstitutional utilisation.

Indeed, commercial utilisation provides themajor theme for the Forum 2001 in June inBerlin. This is where such questions as ‘how toapproach commercial entities’, ‘how topromote commercialisation’, ‘what needs to bedone’ and ‘what resources are required’ will beaddressed. This is the first forum supportingall-Partner globalcommercialisation of theStation, demonstratingthat we are able to offersuch a potential capability.This is really a serious gesture byall five Partners to promote theconcept of commercial utilisation. I amvery pleased to say that we have alreadystarted the initiative, with a lot of workundertaken last year that has already led tosome ideas for commercial utilisation.

We continue the vigorous pursuit of theprocess to find a commercial agent/BusinessDeveloper who will progressively take overmore and more of the commercialisation issue.I firmly hope that we will be able to select sucha Business Developer within the next 2 years.However, we need to firm up on ourpromotion programme before we can makethat selection. The Station is still in its infancyand we need to convince potential commercialusers that this is the way to go, withestablished rules and regulations that are

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crv

IntroductionThe CRV will return International Space Station(ISS) crews of up to seven astronauts safely toEarth in the event of a medical emergency,Station evacuation or if the Shuttle is notavailable. The CRV is the operational version of

the X-38 prototype, whichis being developedcooperatively by NASA,ESA, DLR and 22 Europeanindustrial firms in eightcountries.

CRV Mission ProfileWithin 3 hours of departurefrom the Station, theDeorbit & Propulsion

System (DPS) thrusters are fired to initiate thedescent, and the module is jettisoned. The CRV

enters the atmosphere at an altitude ofabout 120 km, travelling at 27 000 km/h.

Attitude is controlled initially with cold-gas thrusters but, as air pressureincreases, the rudders and body flapstake over. A drogue parachute

deploys at 8 km altitude, stabilising thevehicle in a 1 g sustained sink rate. This isfollowed by the 5-stage deployment of thelarge 685 m2 parafoil. Automatic guidance,navigation and control (GNC) software steersthe CRV through its final descent and landing,with a safe forward speed of less than 10 m/s.

ESA and the CRVBuilding on the expertise developed in theX-38 programme, ESA and the Europeanindustrial team are now transitioning into theCRV programme. Europe brings a wealth ofexperience in reusable manned space systemsand atmospheric reentry (see also the ARDarticle in this issue) to the programme.

CRV development is in two phases: Phase-1includes the design activities up to the CriticalDesign Review; Phase-2 will include theproduction of four operational CRVs, twoCRV/ISS berthing adapters, including theInternational Berthing/Docking Mechanism(IBDM), four DPSs and the provision of sparesand sustaining engineering.

With the full start of Phase-1 in 2001, thefirst operational CRV is expected to be at theStation before mid-2007. Until then, astronautswill rely on Russian Soyuz capsules inemergencies.

Major milestones during the early part ofPhase-1 are the System Requirements Reviewafter 3 months, an Intermediate Design Review(IDR1) at 6 months, the Preliminary DesignReview at 9 months, and the Safety Review andIDR2 at 12 months.

ESA began early Phase-1 activities inDecember 1999: aerodynamics andaerothermodynamics; qualification activities forthe Ceramic Matrix Composite (CMC) material,for the hot structure body flaps, rudders andnosecap Thermal Protection System (TPS);display technique development and man-machine interfaces; design activities for theIBDM; and system and subsystem engineering

TThe Che Crreew Rw Retureturn n VVehicleehicle

Eckart D. GrafX-38/CRV Project Manager, D/MSM, ESTEC, Postbus 299, 2200 AG Noordwijk, The NetherlandsEmail: [email protected]

As the Space Station receives itsfirst modules, NASA and ESA are

on course to develop the nexthuman spacecraft: the Crew

Return Vehicle (CRV). Theprogramme is building on the

technologies and expanding thepartnership developed in the X-38

programme...

The CRV departing from theSpace Station. (NASA)

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as part of the integrated ESA/NASA team at theJohnson Space Center (JSC) in Houston.

Since the programme began, Italy hasconfirmed its participation and Austria hasjoined as the 9th participant. Overall, countrieshave increased their contributions – allowing alarger ESA programme – and have vowed afurther increase no later than at the end ofPhase-1, in order to secure a European rolethroughout CRV’s operational phase, includingthe provision of spares and sustainingengineering. Following the approval of theconsolidated programme by ESA’s MannedSpace Programme Board in September 2000,the Request for Quotation was issued toindustry in early October. The Phase-1 proposal,received in December, is being evaluated, witha view to starting the full Phase-1 in the secondquarter of 2001, synchronised with NASA’sindustrial Phase-1.

The scope of ESA’s participation will gobeyond the X-38 partnership with NASA, andwill include additional subsystems or elements,such as the foldable fins, the fin-foldingmechanisms, the trunnion retraction/extensionmechanisms, the crew seats and the hotstructure body flaps and nose TPS (provided forX-38 by DLR’s TETRA programme).

Europe’s industrial team will also evolvefrom the X-38 team, with MAN Technologie andAlenia Spazio sharing the role of prime

contractor, and leading a team of 19subcontractors in Austria, Belgium, France,Germany, Italy, The Netherlands, Spain, Swedenand Switzerland.

ESA’s CRV Programme is linked to the ISSExploitationProgramme: ESA isnegotiating withNASA the terms of anImplementingArrangement (BarterAgreement), underwhich ESA willreceive NASA-provided Stationservices such astransportation andhigh data-rateservices in return for ESA’s CRV participation.CRV contributions will be deductible from theStation’s variable costs under the exploitationprogramme.

ESA’s participation in the CRVprogramme.

The CRV can carry sevenpassengers. (NASA)

The Deorbit & PropulsionSystem fires to begin thedescent. (NASA)

Genesis of the CRV ProgrammeThe CRV is based on the X-38 technologydemonstration and risk-mitigation pathfinderprogramme. ESA is developing 15subsystems or elements of theV201 X-38 spacecraft, scheduledfor launch by Space ShuttleColumbia in September 2002 (seeOn Station, December 1999; ESABulletin, February 2000). Inaddition, ESA is providing the GNCsoftware for the parafoil phase ofthe V131R and V133 aerodynamicdrop-test vehicles, and for thesupporting tests using a parafoilmicrolight aircraft and large droppallets flying the full parafoil.

The X-38 family of prototypes issupporting a robust flight testprogramme, providing theflexibility to operate and evaluatemultiple flights with parallel rapidturnaround of the test results.

The X-38 is an innovativecombination of a lifting bodyshape (first tested as the X-24 in the late 1960sand early 1970s) and today’s latest aerospace

technology,including CMChot structures forcontrol surfacesand nose TPS, theworld’s largestparafoil, GPS incombination withan inertialplatform forprimarynavigation, and

laser-initiated pyros for deploying parachuteand parafoil, deploying the Landing GearSystem and removing the inhibits for trunnionretraction.

X-24 flight tests resolved technical issuescritical to developing the Space Shuttle, thefirst reusable space transportation system.Today, the X-38 continues that tradition for thenext manned spacecraft.

The growing depth of X-38 design datacombined with continued flight testing isleading to the desired level of crew safety andreliability for the final CRV design. In addition,zero-gravity tests using NASA’s KC-135 aircraftare helping to define CRV operationalcapabilities and man-rating aspects, includingcrew ingress and egress, seat design anddisplay techniques.

In a rapid prototyping environment andusing effective management and decision-

making processes, ESA is developing X-38subsystems at an unprecedented low cost.Flight-testing enabling technologies for man-rated, reusable reentry vehicles creates thebase for European industry’s significant role inCRV development.

X-38 StatusMost of ESA’s subsystems have been deliveredfor system-level integration at JSC. Recentdeliveries were the Pyrex sensor, the noseprimary structure and the first batch of TPSblankets. The CMC leading edges and the fault-tolerant computers (derived from ESA’s DMS-R;

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The X-38 drop test vehicleV131R, at Dryden before itsmaiden flight.

X-38 V-131R is prepared forshipping from JSC. (NASA)

see the article in this issue) with adaptivereentry software will be accepted and shippedto JSC in the next few months. The LandingGear System is ready for assembly once testfixtures are received from NASA.

The V131R, the latest aerodynamic vehicle,refurbished to reflect CRV’s shape, wassuccessfully flight-tested for the first time inNovember 2000; five more V131R flights arescheduled, beginning in May. November’s testscored a number of firsts: first flight of the real(ESA-designed) vehicle shape; first flight of thefull parafoil; first flight controlled by ESA’s GNCfor the parafoil phase.

The V201 spacecraft will be powered up inMarch at JSC, followed by the modal surveytest in July and the acoustic test in September.Shipping to the Kennedy Space Center isscheduled for April 2002.

The Future While the X-38 has beendesigned to address the specificneeds of the CRV programme, itis a flexible, robust and cost-effective testbed that will answera wide range of key questionsabout technologies andoperations of future reusablemanned spacecraft. It helpsresearchers to probe thehypersonic transatmosphericflight regime, and it addressesquestions fundamental toindustry’s future capability fordeveloping operational fully orpartially reusable spacecraft.

There is a need to take a closerlook at potential futuredevelopments beyond the CRV. ACrew Transfer Vehicle (CTV) may

be the next logical step, eventuallycomplementing the Space Shuttle. A potentialevolutionary path from the X-38/CRV to a CTVcould be an initially space-based, fullyoperational vehicle offering augmented on-orbit capabilities such as rendezvous anddocking, as well as routine landing on runways.Evolutionary development from the CRV wouldbe a cost-effective transition for ESA andEuropean industry into the next generation ofreusable manned spacecraft. A European CTVpreparatory programme should be started inthe near term to secure a key role for Europe infuture human spaceflight and exploration. �

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CRV and European Industry

Austria MAGNA: foldable fin

Belgium SONACA/SABCA: aft structure, empennage

SAS/Spacbel: software independent validation,

displays & controls/Man-Machine Interface

Verhaert: trunnion mechanism, IBDM

France AML: aerodynamics

Dassault: aerodynamics/aerothermodynamics

ONERA: aerodynamics

Germany Astrium: parafoil GNC, software independent

validation

DLR: CMC nose thermal protection,

aerodynamics/aerothermodynamics

MAN Technologie: industrial lead,

body flap assembly

Italy Aermacchi: aerodynamics

Alenia Spazio: industrial lead, nose

primary structure

CIRA: aerothermodynamics, Scirocco plasma facility

SICAMB: crew seats

Netherlands Fokker: rudders

NLR: aerodynamics

Spain Sener: landing gear, IBDM

Sweden FFA: aerodynamics

Switzerland Contraves: fin folding mechanism

First flight test of the X-38vehicle V131R, in November2000. (NASA)

The X-38 spacecraft V201 inassembly at JSC. (NASA)

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dms-r

What is the Data Management System?DMS-R provides command and control forZvezda and the entire Russian Segment,guidance, navigation and control (GNC) for the

whole Station, and missionmanagement by groundcontrol and crew. Theproject’s history goes backto 1992 when discussionsbegan with Russia on ESAcontributions to a Mirsuccessor. It was only in

1994 that the project took shape with thefusion of the Mir-2 and Freedom programmesinto the International Space Station. ESAagreed to provide a set of highly advancedcomputers as the core of the avionics for theRussian Service Module. In parallel, ESAbenefits by reusing these computers for itsown Columbus and Automated Transfer Vehicle(ATV).

DMS-R Design, Development and Delivery The DMS-R architecture (see figure) consists of:

• two Fault Tolerant Computers (FTCs) servingas Zvezda’s Central computer (CC) andTerminal Computer (TC) connected to MIL-STD 1553 busses. They have built-in faultmasking and each consists of threeinterconnected identical processing units(lanes) working by majority voting;

• two Control Posts (CPs) for the crew and forcommanding experiments and theEuropean Robotic Arm via MIL-STD 1553busses. They can be configured to executedifferent tasks or to operate redundantly.Each CP can use two laptops (commercialruggedised PCs, standardised, qualified andprovided to all Station partners by NASA) asthe Man-Machine Interface;

• the ground infrastructure and facilities forsoftware development, integration and test.

Development started in 1994 by a Europeanconsortium headed by DASA in Bremen (D),leading to delivery of the first flight units toRussia’s Zvezda contractor RSC Energia inNovember 1997. The software underwentrefinement from 1998 to early 2000, based onfield experience and implemention of latechanges in hardware and software requestedby RSC Energia as they developed Zvezda’sapplication software.

Flight ExperienceAn ESA/Industry support team worked jointlywith Russian flight controllers at the TsUPcontrol centre near Moscow during launch,docking with Zarya and installation of the firstControl Post computer and laptops by theExpedition-1 crew.

On 12 July 2000, the two FTCs wereactivated 2 hours before launch from Baikonur.Telemetry was monitored, especially theinternal temperature. Telemetry was limitedduring Proton ascent but what was availablewas normal. When Zvezda separated fromProton, commands were triggered in the twocomputers to deploy the module’s externalelements and to switch onboard systems fromstand-by into active mode. Before Zvezdapassed out of ground station contact, allperformances were verified as normal. Theother orbital passes during this first day sawvarious equipment commands and activationinside Zvezda from TsUP, with constantmonitoring on the consoles. Some 3 hours afterlaunch, temperatures inside the computers hadstabilised at 35ºC, well below the predictionused during development to assess theirreliability. It is therefore expected that each

The DMS-R data managementsystem provided by ESA for the

Zvezda module of theInternational Space Station has

now been operating successfullyin orbit for more than 6 months...

Daniel GuyomardSystem Integration Office, D/MSM-MSP,Postbus 299, ESTEC, 2200 AG Noordwijk, The NetherlandsEmail: [email protected]

DMSDMS--R in CR in Conontrtrolol

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computer will exceed its calculated life of up to5 years.

The next 2 days saw the main engines adjustthe orbit under DMS-R control, as well asvarious GNC testing and verification using starsensors and inertial navigation systems. Flightcontrollers performed an end-to-end test ofthe radio command and telemetry system withthe DMS-R computers, ensuring propercommand and telemetry configurations whilecycling through Zvezda’s various softwaremodes.

On one occasion, a general exception in theapplication software of the Terminal Computerled to a reset. The computer successfullyrestarted and returned to normal operationwithout losing attitude control. Discussionbetween RSC Energia and DMS-R supportengineers produced the explanation that aground command to the SIMVOL displaysystem provided an unexpected erroneousresponse. Mass restrictions had forced Zvezdato be launched with only a subset of SIMVOLfor rendezvous and docking.

The day before docking, controllers notedthat a CC lane was in standby mode. Initialanalysis concluded there was no error in theDMS-R hardware or software and that theanomaly resulted from the applicationsoftware response to some specific timingconditions. It was recommended that dockingcould proceed as normal with the 2-lane CC.

The docking was successful in thisconfiguration. However, during the first orbitafter docking, telemetry indicated that anotherCC lane had also reset and was in standby,leaving only one active lane. After a data dumpvia the telemetry system, it was assessed thatthe cause was the same. Meanwhile, the CCcontinued to perform normally. However, ESAand RSC Energia engineers agreed thatreestablishing the three lanes was necessarybefore DMS-R was connected to the Stationbus. The integration of Zvezda’s CC data busseswith the computer systems of Zarya and Unitythen proceeded without problems. DMS-R’scomputers were now not only responsible forZvezda command and control but also for GNCfor the whole Station.

The two computers continue to performnormally despite a few more instances of laneisolation. They are not critical and RSC Energiaengineers devised a fix for the applicationsoftware to be uploaded before the arrival ofthe US Destiny laboratory in February 2001.

One CP computer and its two laptops

arrived aboard the Progress-M1-3 supply ferryin August 2000. They were unloaded by thecrew of STS-106 in September and on4 November the computer and laptops weremechanically installed, cabled, switched on andbooted by the Expedition-1 crew. The fullactivity took 3 hours, spread over three orbitsbecause of incomplete ground coverage. Withthis installation, the crew could now commandZvezda.

However, in mid-November, one laptopwould not reboot and when the secondsuffered the same problem 2 weeks later thecrew could no longer interact normally withZvezda. As of January 2001, the problem wasstill under investigation and not fullyunderstood. It is not a hardware failure, butmore probably a corruption of the SOLARISoperating system on the laptop hard disk aftera non-nominal shutdown or crash. Without abackup, the crew could not recover thesituation. STS-97 delivered a new hard disk inDecember with configured software so that thecrew could recover one laptop. The faulty harddisk was brought back by the Shuttle foranalysis.

The Future The second CP computer was delivered bySTS-98 in February and installed byExpedition-1 that month, completing the fullon-orbit configuration of DMS-R. In order toprovide long-term support, identical new FaultTolerant Computers are being manufacturedby Astrium to be available from March 2001 foruse as required. Some of the computers will beprovided under the original DMS-R agreement,while others are in exchange for Russiansupport for ATV. ESA is also negotiating withRussia to provide long-term DMS-Rengineering support throughout the life of theStation. �

Gidzenko working with the laptops of the Control Post computers.

DMS-R architecture aboardZvezda. CC: CentralComputer. TC: TerminalComputer. FCR: FaultContainment Region.FTC: Fault TolerantComputer. CP: Control Post.SM S/S: Service Modulesubsystems. FGB: Zaryamodule. ERA: EuropeanRobotic Arm.ATV: Automated TransferVehicle. TC: telecommand.TLM: telemetry.GNC: Guidance, Navigation &Control.

The two sets of 3-box FaultTolerant Computers of DMS-Rinstalled in Zvezda beforelaunch.

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gts

IntroductionIn 1996, following the successful Euromir-95mission, ESA negotiated with RSC-Energia theEuromir Extension mission. Euromir-E shouldhave taken place towards the end of 1997, and

reused much of ESA’sequipment alreadyonboard Mir. However, theProgress collision in June1997 destroyed these plans– the vast majority of ESA’s

equipment became inaccessible inside thedamaged Spektr module.

Instead, ESA and RSC-Energia agreed at theend of 1997 to devote the financial resourcesfrom Euromir-E to Western Europe’s firstscientific endeavour on the International SpaceStation (ISS). At this stage, GTS was anexperiment proposed by the German SteinbeisTransferzentrum Raumfahrtsysteme (TZR) andwas highly recommended by the ESA PeerGroups. Following an in-house feasibilityassessment, GTS stepped in to replaceEuromir-E.

The Objectives and Concept of GTSTime-signal stations on Earth usually transmittheir information at long wavelengths. Watchessynchronise themselves with these signals byactivating their receivers typically once per dayor after turn-on. In Germany, the signal isbroadcast by the Physikalisch-TechnischeBundesanstalt (PTB), in Braunschweig, using asimple encoding scheme to transfer both timeinformation and synchronisation impulses on a77 kHz carrier. Although this scheme is quiteefficient and simple, it has severaldisadvantages:– the time signal is only Europe-wide, within

2000 km;– moving between countries requires different

receivers and decoders;– the low data rate requires lengthy, good

receiving conditions.

To overcome these limitations, GTS willtransmit a UTC time signal from the SpaceStation via an external antenna with a broadantenna pattern. The Station’s orbit means thatthis signal is transmitted over almost the wholeEarth each day. The signal can be received atany location several times daily, for 5-12minutes at a time, strong enough for evensmall wristwatches. GTS also broadcasts theStation’s current orbital position, so clocks‘know’ their local time zone without userinteraction.

Further main scientific objectives are:– to verify the performance and accuracy of a

time signal transmitted to the Earth’s surfacefrom low orbit under real space operationalconditions;

– to measure the signal quality and data rateson the ground;

– to measure disturbing effects such as

TTrransmitting fransmitting from Som SpacpaceeThe Global Transmission Services Experiment

The Global Transmission Servicesproject will be Western Europe’s

first major experiment aboard theSpace Station....

Jens D. SchiemannGTS Project Manager, D/MSM-GU, ESTEC, Postbus 299, Noordwijk 2200 AG, The NetherlandsEmail: [email protected]

The GTS Antenna Unitinstalled on Zvezda.

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Doppler shifts, multi-path reflections,shadowing and elevation effects.

Experiment Set-upGTS essentially consists of two major elementsin the Station’s Russian Zvezda module: theElectronics Unit (EU) and the Antenna Unit(AU).

The EU accommodates all the elements forthe experiment, signal generation and signaldistribution. In addition, it provides thenecessary command and control interfaceswith the Station’s Russian Segment for GTSdata exchange, telemetry transfer, GTStelecommanding and data receipt fromZvezda’s systems, such as orbital data.

A main EU feature is the ultra-stable quartzoscillator (USO). This oscillator is the core of thelocal time generator, and provides an accuracyof up to 10-13. If synchronised almost every orbitwith an atomic clock on the ground – such asthe one at PTB – GTS generates an onboardtime-signal reference of unprecedentedaccuracy for the Station’s own applications. GTSprovides this signal to Zvezda’s systems andother scientific onboard users via a pulse andfrequency output.

Being only 350x300x210 mm in size, the EUwill be housed in the Zvezda module, behindPanel 408.

The EU generates the GTS signal on twofrequencies – 400.1 MHz and 1.4 GHz – fortransmission to Earth by the AU. Thetransmitter includes a digitally controlledfrequency synthesiser that allows testing ofvarious frequencies and modulationtechniques. Specific modulation techniqueswill be applied in order to avoid interferencewith other ground-to-space links aboard theStation.

The antenna has specially shaped radiatorsto create a near-constant signal strength onthe ground down to 15° above the horizon forthe receiver during the Station’s pass. The UHFmain beam uses a 4-element phased array. Thebeam can be rotated in eight steps with anangle of 70° relative to nadir using beam-forming electronics located on the back of theantenna plate. The power and commandsignals are routed together with the RF signalsthrough two coaxial cables. For extendedservices, requiring larger bandwidths than atime signal, the L-Band (1.4 GHz) with itsdedicated antenna on the AU is used.

In December 1998, the AU’s hardwaredevelopment, integration and test activitiesended with its installation on an EVA handrailon Zvezda, along with the RF cables. Zvezdaand the AU were safely launched into orbit inJuly 2000.

Experiment Operation SummaryData and time information destined for GTSwill be transmitted from the experimenter’s sitein Stuttgart, Germany and directly received byGTS. The ground station will supply GTS withthe synchronisation marks and pre-calculatedground track information needed to minimisethe active time for the ground receivers. TheGTS internal clock is adjusted and/orsynchronised using this dedicated uplink. Inorder to maintain this clock’s very highaccuracy, this adjustment is required at leastonce per day.

The Mission Control Centre in Moscow

GTS block schematic.

The flight model of the GTSElectronics Unit.

(MCC-M) will control the on/off of the GTSElectronics Unit. In addition, a dedicatedcapability controlled by MCC-M allowsindividual transmitter switching in specificoperational cases.

The GTS continuously transmits time andand information on the Station’s position alongits ground track. These data are complementedby GTS housekeeping telemetry. Equipmentstatus and housekeeping data will also betransmitted via a dedicated telemetry interfaceto MCC-M. The GTS time signal can be issuedvia the dedicated data interfaces to theStation’s data management system to serve as the reference time signal for the wholeStation.

In order to maximise the scientific returnGTS will operate autonomously and preferablycontinuously. Intervention, such as theswitching of transmitters, is normallyperformed by MCC-M and not the crew.

Interrupting the experiment runs (powershut-off, transmitter switching) needs to beavoided. Reactivation after any shutdown ofthe experiment costs 8-10 days in clockrecalibration before the measurements can runnormally. GTS is designed to operatecontinuously for the 2 years agreed withRSC-Energia.

Status and PlanningThe GTS Electronics Unit completed Final FlightAcceptance in mid-March, aiming for launch tothe Station aboard a Progress ferry towards theend of April. It is envisaged that theExpedition-3 crew will install the EU andactivate GTS around the beginning of July2001. Then, after functional verification, GTScan be declared operational towards the end ofthat month.

GTS ApplicationsAt present, two concrete applications areforeseen:– time signals for worldwide clock

synchronisation,– secure code transmission for anti-theft

devices that can deactivate a stolen car andits keys.

It could be argued that the clock applicationcould also be implemented using GlobalPositioning System signals. However, GPS hasmajor drawbacks:– no local time zone information (political

and/or geographical) is provided;

– no daylight savings time information isgenerated;

– without L-band signals, wristwatches cannotuse the service;

– GPS is a military system and can deliberatelybroadcast erroneous signals if required.

In order to minimise the computationaleffort and power consumption in wristwatches,GTS continuously transmits the local time forthe Station’s current ground spot. The receiversdetect the moment of the closest Stationapproach by measuring the signal’s Dopplershift. The ambiguity of a left or right passage isresolved using the rotating beam information.From these data, the receiving clockdetermines the correct time data packet for itscurrent position. Via the EU’s computer,changes in time zones, daylight savings andUTC time adjustments can be easilyimplemented through commands from thecontrolling ground station.

Compared with GPS, the Station is an idealplatform for instant repairs and, in comparisonwith satellites, offers rapid replacement offaulty hardware via the frequent uploadopportunities and crew availability. Thisapproach offers simpler design solutions, whichlower development cost and save time.

The anti-theft application demands a securesignal to receivers small enough to be

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gts

integrated into car keys. Such a signal must be:– difficult to imitate, so that it cannot be faked

with a transmitter on the ground;– non-repeating, so that it cannot be recorded

and replayed to simulate a true signal;– fail-safe, i.e. the hardware must be

redundant and easy to service.

The combination of non-linear pseudo noisespectrum signals, the large Doppler shift andthe orbit information form a fingerprint thatcannot be faked by car crackers on the ground.

The Commercial Potential of GTSFrom the beginning, GTS was conceived as acommercial application. It has followed notonly a new approach to developing spacehardware for new services, but also anapproach on how future operations costs canbe financed through a ‘service providercompany’, founded by the development andresearch partners and financed through sellinglicences and specific services to end users.

The commercial structure of the GTSDevelopment Project can be summarised as:– the main industrial partner in the ground

segment is Fortis Uhren GmbH, whodeveloped the hardware for the experimenton their own and who will make therequired ground tests using the Stationsignals, thereby implementing the standard

GTS services that are the core of thecommercial utilisation;

– TZR developed the space segment(supported by DLR) and is coordinating thescientific utilisation of GTS;

– the flight opportunity, covering integrationand launch, the operation in space duringthe 2-year experimental phase, andassociated ground infrastructure services(e.g. data exchange with MCC-M) is providedby ESA.

GTS aims at near-term commercialisationand is therefore financed by industry to asignificant extent. The ground segmentrequired the development of new receiverchips and their integration into wristwatchesand car electronics. The total developmentbudget is about EUR6.5 million, of which 53% ispublic funding (ESA and German national) and47% is industrial funding.

During the 2-year initial experiment phase,the GTS hardware will be operated by TZR, thescientific coordinator. Plans are already takingshape to found a GTS Service Company, withthe partners participating as ‘shareholders’.Commercial utilisation during this initial phasewill then be coordinated through the ServiceCompany. As ESA is providing the flightopportunity andoperations, as wellstimulatingStation commer-cialisation, it willparticipate in thecompany.

For the future,apart frommanaging GTSlicensing andprovidingcontinuedservices, the Service Company will most likelyalso have to establish contracts with theStation Partners in order to ensure continuedGTS services on the ISS, make hardwareupgrades and issue and manage licences toend-users to refinance the operational costs ofthe hardware or invest in future developments.

The main GTS ground station will beoperated by the Service Company. It will alsotake responsibility for user interfacing, dataprocessing, transmission to and from the GTShardware (e.g. in the case of car theftprotection activation) and provide marketingand promotion services. �

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The GTS Antenna Unit on theZvezda module.

GTS development costs share.

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sts-107

IntroductionFor 15 years, Spacelab was the workhorse forwestern research in the life and physicalsciences under microgravity conditions(10-5-10-6 g), stretching from the first mission in1983 to its last, Neurolab, in 1998. The

international microgravityuser communityrecognised early on thatthe International SpaceStation (ISS) would not be

fully operational for its needs before 2005. Itthus urged NASA to bridge the long gap inresearch opportunities by flying microgravitypayloads on Shuttle missions.

The first, STS-95 in late 1998, included anESA microgravity package with the AdvancedGradient Heating Facility (AGHF), AdvancedProtein Crystallisation Facility (APCF), Biobox,Facility for Adsorption and Surface Tension(FAST) studies and Morphological Transitions ina Model Substance (MOMO) facility. STS-95 isperhaps better known as the John Glenn andPedro Duque flight! After this mission, NASAagreed to include a series of research missionsin the Shuttle manifest. These will use ShuttleColumbia, which is too heavy for ISS assemblyor supply flights, but it has an extended

duration operations kit for missions of typically16 days. The commercial Spacehab pressurisedmodule carries the research equipment.

The STS-107 MissionThe Spacehab Research Double Module (RDM)will make its maiden flight on STS-107. NASA’srental agreement makes owner Spacehab Inc.and subcontractor Boeing fully responsible forpayload integration in the RDM and in theShuttle middeck, and for its operation duringflight, controlled from NASA’s Johnson SpaceCenter (JSC) in Houston, Texas.

Payload integration, verification and test isunderway in the Spacehab Payload ProcessingFacility (SPPF) in Port Canaveral, Florida, next tothe Kennedy Space Center (KSC) launch site.

The ESA PayloadSpacehab missions are organised commercially,which means that access has to be contractedwith Spacehab, Inc., normally on a US$/kg pricebasis. For STS-107, this applies to 230 kg ofESA’s payload. But there are other ways to getaboard:

• 300 kg come from the barter arrangementwith NASA in return for providing a Guppytransport aircraft;

• 50 kg are an ESA ergometer counted asNASA return for including a US experimentin Biopack.

ESA’s payload encompasses seven separatefacilities. Apart from the COM2PLEX technologyfacility of the Technology Flight Opportunities(TFO) Programme, they are all funded by theEuropean Microgravity Research Programme(EMIR). In total, 37 ESA life and physical sciences

Shuttle mission STS-107 will be amajor flight for ESA’s microgravity

research programme...

STS-107

Launch: October 2001 (depends on higher-priorityISS and Hubble Space Telescope missions)

ESA payload: APCF, ARMS, Biobox, Biopack, ERISTO,FAST, COM2PLEX

Payload mass: 3630 kg (3300 kg in Spacehab &330 kg in middeck), including 580 kg from ESA

Mission duration: 16 days (+2 days margin)Orbit: altitude 280 km, inclination 39ºCrew: 7, working in two shifts

Werner RiesselmannHead of Microgravity Payloads Division, D/MSM, ESTEC ,Postbus 299, 2200 AG Noordwijk, The NetherlandsEmail: [email protected]

BBrr idging the Gidging the G apapESA’s Microgravity Research Aboard STS-107

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experiments will be accommodated onSTS-107.

The experiment ‘Choroidal regulationsinvolved in the cerebral fluid response toaltered gravity: water transports andserotoninergic receptors’ requires rats to behoused in NASA’s Animal Enclosure Module(AEM). As this is similar to a NASA experiment,ESA’s researcher will receive her rat tissues fromNASA within a day of landing.

Advanced Protein Crystallisation FacilityAPCF is ESA’s ‘frequent flyer’ forprotein crystallisation research inspace. It has already flown onSpacehab-1 (June 1993),IML-2 (July 1994),

USML-2 (October 1995), LMS (June 1996) andSTS-95/Spacehab (October 1998). ESA has two

identical flight models that can each carry upto 48 individual and different experimentgrowth reactors, of which up to 12 can beobserved by a video and a Mach ZenderInterferometer subsystem. Protein growthtemperatures can be selected between 4°C and30°C (20°C for STS-107). APCF requires anastronaut to turn it on and off but it otherwiseautomatically follows a preprogrammedprocessing profile that includes the recordingof up to 5000 video/interferometer stills.

APCF is designed for Shuttle MiddeckLockers (MDLs), which means it can fly on theactual middeck, Spacelab, Spacehab, ISSExpress and ISS European Drawer Racks. MDLsallow late access before launch and soon afterlanding – a prerequisite for sensitive proteins,since some degrade rapidly after insertion intotheir growth reactors. On STS-107, eight

experiments occupy 38 growth reactors.The second APCF flight model will probably

fly even earlier than STS-107: it is beingprepared as ESA’s first microgravity payloadaboard the Space Station. It will be launchedwith ISS assembly flight 7.A1 in mid-2001 to beinstalled in an Express Rack in the US DestinyLab, and returned on UF-1 in November 2001.

Advanced Respiratory Monitoring SystemARMS is a new development, mainly forpulmonary and cardiovascular research,

succeeding instruments flown as part ofEuromir and Anthrorack aboardSpacelab-D2. ARMS’ core instrumentsare two Photo- and MagnetoacousticGas Analysers complemented byinstrumentation such as valves,

flowmeters, gas supplies with fourdifferent gas mixtures, blood pressure, ECG

and breathing frequency measurementequipment, Infrared Pulse Oxymeter,

Haemoglobin Photometer Spirovis and abicycle ergometer to stress the subjects. ARMSis a rather complex set-up that astronautsassemble in orbit from many stowed items.

Eight groups of investigators will use ARMSduring STS-107, although one will makemeasurements on the whole crew only beforelaunch and after landing. The research fieldscover heart control and regulation, pulmonaryphysiology (including both lung mechanicsand gas exchanges) and orthostaticintolerance. The experiments will be performedat the mission’s beginning, mid-point and end

APCF design andaccommodation in an MDL.

Protein crystals grown in APCFduring STS-95. Interferometryshows the evolution of saltand protein concentration inthe reactor chamber.(J.M. Garcia Ruiz et al.)

ESA astronaut Andre Kuiperstries the ARMS TrainingModel.

to study both the early adaptation and theachieved steady-state. This requires a total crewtime of about 78 hours.

In addition, an important part of theresearch is done on the ground: pre-flight toestablish the individual reference baseline ofeach of the four ARMS astronauts, and post-flight to study the return to 1 g. Both fast- andslow-recovery systems will be studied afterreturn (landing +2 hours) until a month and ahalf later.

Training is an important part of the missionpreparation. The crew has to learn to set-up,stow and use the equipment, and to performthe different breathing ‘manoeuvres’, such ascontrolling inspiration or expiration flow at0.5 litre/s.

BioboxThe multi-userBiobox wasoriginally designedto fly on Russia’sFoton and Bionretrievable capsules.After three flights in1993, 1995 and1997, it was adaptedfor Spacehab andmade its first flighton STS-95.

Biobox isessentially anincubator (6-38°C)that canaccommodate 24

experiments in static (microgravity) positionsand six in a 1 g reference centrifuge. Bioboxworks ‘hands-off’ – it runs automatically frominstallation in Spacehab until landing. Thetemperature and centrifuge speed can beadjusted by ground control by telecommand.

During STS-107, four experiments will usebone cell cultures (osteoblasts, haemopoieticcells and osteoclasts) from humans and mice. Asecond Biobox will operate on the ground as a1 g reference.

BiopackBiopack is now finishing development for itsdebut on STS-107. It is designed to fit in anydouble-MDL position in the Shuttle, Spacehab,ISS Express Rack or ISS European Drawer Rack.Biopack is an incubator (22-37°C) with static(microgravity) and dynamic (three centrifugescontrollable 0-2 g) accommodation positions

for standard experiment containers of Type 1/E(65 ml internal volume) and Type 2/E (385 ml).For storing experiment containers, Biopackincludes a refrigerator/freezer (4°C or -15°C)and a freezer (-15°C).

Apart from astronauts handling experimentcontainers, Biopack can be run fullyautomatically with telescience control from theground. However, all functions can also bemonitored and controlled from its Control andMonitoring Panel by the astronauts. OnSTS-107, Biopack will be used for eightexperiments in 78 containers on mammaliancell and tissue cultures, and bacteria.

As for other biology facilities, the Biopackengineering model will run on the groundduring the mission as a 1 g reference.

European Research in Space and TerrestrialOsteoporosis (ERISTO)ERISTO, one of more than 40 ESA MicrogravityApplication Projects (MAP), makes use of theOSTEO facility developed and already flown bythe Canadian Space Agency on STS-95.

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Biobox, with the lid removed, isinstalled in Spacehab.

An ERISTO payload tray.

bioreactor (3)

valves

fixativesyringe

nutrientsyringes (3)

sample

carrier

Biopack: the topcompartment carries therefrigerator/freezer; theincubator and centrifugesare in the bottom.

ERISTO’s long-term goals are a betterunderstanding of the role played bymechanical stress in osteoporosis and to helpdevelop countermeasures against bone-loss onlong space missions. It is hoped that the resultscan be adapted to fight osteoporosis on Earth.

Two ERISTO experiments will study theresponses of osteoblasts (bone-forming cells)and osteoclasts (bone-resorbing cells or cellsthat break down bone) to various drugs andgrowth factors under microgravity conditions(i.e. under reduced mechanical stress).

ERISTO consists of an incubator housing fouridentical trays with three experimentspecimens each. The Spacehab locker will beinstalled only 40 hours before launch. In orbit,the crew will follow a precise procedure inoperating valves, syringes with nutrients andsyringes with fixatives. The same will be donewith the 1 g reference ERISTO unit on theground.

Facility for Adsorption and Surface TensionFollowing its debut on STS-95, FAST will run a

series of experiments to measure the responseof surface tension to carefully controlleddynamic changes in surface area, free from theperturbing effects of buoyancy and convectionthat limit ground-based investigations. Whileexecuting its three experiment programmessemi-autonomously, FAST will send science and

housekeeping data to the ground by video andtelemetry. Telescience will allow theinvestigators to modify experiment parametersand experiment sequencing by telecommands,if required, after a preliminary analysis of thescience results.

FAST is carried in two adjacent lockers onSpacehab’s aft bulkhead: one for the FacilityController and the other for the twoExperiment Units. The Principal Investigatorsare involved in ESA’s MAP on Fundamental andApplied Studies of Emulsion Stability thatforesees FAST flying aboard Columbus.

COM2PLEXThe COMbined European 2Phase LoopEXperiment has integrated three different loopheatpipes into one technology experiment,mounted outside on Spacehab’s flat roof. Loopheatpipes – highly efficient heat transportsystems using an evaporation/condensationcycle inside a closed loop (similar to classicalheatpipes) – have been developed in the lastfew years and are key technology elements for

deployable radiators, thermal control oflaser-based instruments, and heattransfer from remote equipment toradiators. Two-phase phenomena(evaporation, condensation, two-phaseflow) behave differently in 1 g and low-g,so testing and in-orbit qualification aremandatory to mature this newtechnology.

OutlookThe only major uncertainty with STS-107is its launch date, which could bebetween September 2001 and April2002. This is because NASA awardshigher priorities to Shuttle flights for theSpace Station and Hubble SpaceTelescope than to microgravity researchmissions.

Another microgravity researchmission is already being planned:STS-118 is assigned in the manifest. Asour two agencies plan to refly part ofSTS-107’s payload, a minimum gap of 15-18 months is required for refurbishing

the experiment facilities. This means thatSTS-118/Spacehab is not expected to fly beforespring 2003.

An unmanned microgravity mission is also inpreparation: the 14-16 day Foton-M1 flight inlate 2002. Negotiations with Rosaviakosmos arealmost completed. �

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FAST installed in Spacehabfor Interface Verification andTesting.

Mission Accomplished!

The first phase of the long-termoccupation of the International SpaceStation has been successfullycompleted. The Expedition-1 crew ofISS Commander Bill Shepherd, SoyuzCommander Yuri Gidzenko and FlightEngineer Sergei Krikalev returned toEarth on 21 March (as this issue wentto print), having handed over to theExpedition-2 crew of ISS CommanderYury Usachev and Flight EngineersJim Voss and Susan Helms.

During their 4-month tenure, thefirst crew hosted three visiting Shuttleteams delivering the first large solararrays, the US Destiny sciencelaboratory, Destiny’s first science racksand the first Italian-built Multi-Purpose Logistics Module (MPLM).

STS-102/5A.1 docked with PMA-2at 06:38 UT on 10 March to begin thesecond expedition. Usachev wasthe first through when thehatches were opened at08:51 UT, immediatelyswapping places withGidzenko. On 12 March, Vosstook over from Krikalev, andShepherd with Helms on14 March. Shepherdremained in command untilan hour before final hatchclosing. As they switched,they exchanged their personalisedseat liners in the Soyuz escape craft.The mission also continued theoutfitting of Destiny through twospacewalks and the delivery oflogistical items, spare parts andhardware in MPLM Leonardo. Theseincluded the first science racks,including the Human ResearchFacility, a mainstay for studying theeffects of weightlessness on humans.

Usachev, Voss and Helms areexpected to stay aboard until July,when they will be replaced by theExpedition-3 team of ISS CommanderFrank Culbertson, Soyuz CommanderVladimir Dezhurov and FlightEngineer Mikhail Turin. During theirtenure, they will host three Shuttle

visits and begin researchaboard the Destiny,outfitted by three MPLMs.Their Soyuz escape craft

will be replaced by a freshvehicle, and the Russians will

add a docking compartment toZvezda.

Umberto Guidoni will be the firstESA astronaut aboard the ISS as partof the Shuttle STS-100/6A mission inApril. Late April will also see a Progresssupply vehicle carrying the electronicunit for the European GlobalTransmission Services (GTS)experiment. GTS will allow thesynchronisation of radio-controlledclocks and watches from space and, inthe longer term, the disabling ofstolen cars and credit cards. See thearticle on pp.10-13 of this issue forfurther information.

On Station #4 (December 2000)took the story of Expedition-1through the early days of their

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on Station no. 5 march 2001

station update

Station Update

occupation. Their first Progress supplyship (#M1-4) brought 2 t of food,clothing, hardware and gifts fromtheir families on 18 November 2000.Progress should have used the Kurssystem to dock automatically withZarya’s nadir port, but failed to lockon. Instead, Gidzenko assumedmanual control at 03:02 UT using theTORU system installed in Zvezda andguided Progress in using Soyuz-typehand controllers, but had to halt 5 mout when sunlight blinded the foggedcamera lens on Progress. He movedthe ferry back to 30-40 m and waitedfor orbital darkness before docking itat 03:48 UT. Soon after, the crewbegan leak checks at the dockinginterface before opening the hatchesand beginning 7 days of unloading.This is the first time a radial dockingport has been used on the Station.Progress was undocked at 16:20 UTon 1 December to clear the way forShuttle STS-97’s docking with the

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Expedition-2 crew (from left): Voss,Usachev and Helms.

The Station’s research activities will begin in earnest inDestiny (foreground) once the laboratory is outfitted.Shuttles will now dock at the axial PMA-2 position;PMA-2 is at Unity’s nadir port.

How the Space Station looked after the arrival ofDestiny (bottom). The Soyuz escape craft (top) was latermoved to Zarya. Inset: Cockrell (left) and Krikalev beginoutfitting Destiny.

Station Update

Unity/PMA-3 nadir position, againused for the first time.

STS-97 with Commander BrentJett, Pilot Mike Bloomfield andMission Specialists Joe Tanner,Canada’s Marc Garneau and CarlosNoriega docked at 20:00 UT on 2December 2000. Just over 2 hourslater, Garneau used Endeavour’s robotarm to lift the 16 t P6 solar array trussout of the cargo bay, leaving itpositioned overnight to warm itscomponents. The next day, Garneauslotted P6 into position at 19:32 UTon the Z1 truss structure on Unity.Spacewalkers Tanner and Noriegabolted it down before Garneaureleased it. Standing on the arm,Noriega moved around P6 to connectnine power, command and datacables. Computer commands fromthe Shuttle to release the pinsholding the solar array containersclosed were not initially successful.Repeat commands deployed thestarboard wing in a 13-minutesequence but one pin on the portside remained closed. A radiator wasthen deployed to dissipate heatgenerated by the power module. Theport wing was finally deployed on4 December over a period of 2 hours.It had been delayed while groundcontrollers studied an apparentslackness in one of the two starboardblankets. They believed that twotensioning cables had jumped offtheir guides during deployment.

This first of the Station’s four solararrays, spanning 73 m, can generate64 kW under optimum conditionsfrom its 66,000 8 cm-sq solar cells. Asecond EVA by Noriega and Tanner,on 5 December, hooked up powerand data cables and connectedammonia coolant lines between P6and Unity. They also moved theS-band antenna assembly from Z1 tothe top of P6’s tower and released

restraints holding another radiator,allowing it to be deployed after theirEVA for early Station cooling. At thesame time, the Station crewreconfigured cables inside Unity toroute electricity from the new array tothe rest of the Station. On6 December, 3 kW was routed toZvezda for the first time, bringing itstotal to 6-7 kW. When STS-97departed, the wings were providingan average of 13 kW to the Station.

The third and final EVA, on7 December, when Noriega andTanner tensioned the slack starboardblankets, brought the total EVA timeduring STS-97 to 19 hr 20 min. TotalEVA time outside the Station was now88 hr 54 min (all EVAs are still fromthe Shuttle airlock, until the Russiansattach their Docking Compartment inAugust and NASA the Joint Airlock inJune).

The two crews did not meet until8 December because the hatches hadremained closed while the Shuttleoperated at a lower air pressure forthe EVAs. After swapping equipmentand rubbish, Endeavour undocked at19:13 UT on 9 December. With thenew power supply, the Expedition-1crew now had continuous access toUnity. Without power, they had notentered it for the first time until

3 December.The crew celebrated Christmas by

opening gifts delivered by Progressand STS-97.

Progress-M1-4, undocked on1 December, had been commandedto a distance of 2300 km whilecontrollers decided what to do withit. The failure of its Kurs automaticdocking system prompted engineersto devise a software patch and test itout on 26 December. Progressbrought itself to within 200 m ofZarya’s nadir port, where Gidzenkotook over manual control using theTORU system for the link-up. Rubbishand surplus items were loaded into

Progress for incinerationduring its destructivereentry over the Pacificafter undocking at11.26 UT on 8 February2001 to clear the way forSTS-98.

STS-98 withCommander Ken Cockrell,Pilot Mark Polansky andMission Specialists Bob

Curbeam, Marsha Ivins and Tom Jonesdocked with the Unity/PMA-3 nadirposition at 16:51 UT on 9 Februarycarrying the Station’s first researchmodule: the 13.38 t Destiny. In fact,Destiny is the core of the wholeStation. At $1.4 billion it is theStation’s single most expensiveelement, and its 13 computers are thecommand and control node for thecomplex. Its activation meant thatHouston replaced Moscow as thelead control centre. Destiny added110 m3 to the Station, increasing theliving space by 41%, and giving it alarger volume than any space stationin history. Station mass is now 100 t.

Ivins began the installationsequence, using the Shuttle’s roboticarm to remove PMA-2 at 15:00 UTfrom Unity’s end position to makeroom for Destiny. She latched it in atemporary position on the Z1 Truss.At 15:50 UT Jones and Curbeambegan their EVA to work in tandemwith Ivins. Jones provided her withvisual cues as she moved the adapterto its temporary position, andCurbeam removed protective launchcovers and disconnected power andcooling cables between Destiny andAtlantis. Ivins latched the arm ontoDestiny at 17:23 UT and lifted the

module from the Shuttle payload bayat 17:35 UT. High above the bay, sheflipped it 180°, and at 18:57 UTDestiny was latched into position onthe Station. A set of motorised boltstightened to hold it permanently inplace.

With Destiny secured, Jones andCurbeam began connectingelectrical, data and cooling lines.While Curbeam was attaching acooling line, a few frozen ammoniacrystals leaked briefly. He remainedin the Sun for half an hour to vaporiseany crystals on his spacesuit whileJones brushed him off. Theyperformed a partial pressurisationand venting of the Shuttle airlock toflush out any ammonia before a finalrepressurisation. As the airlock beganexchanging air with the Shuttle cabin,Cockrell, Polansky and Ivins woreoxygen masks for about 20 minutes.In the end, no smell of ammonia wasreported.

At about 02:20 UT 11 February,Cockrell and Shepherd beganremotely powering up key Destinysystems and cooling equipment,sending commands via a laptopcomputer. They were the first toenter Destiny, at 14:38 UT 11February, to begin the day-longoutfitting activities. This included theactivation of air conditioners, fireextinguishers, computers, internalcommunications systems, electricaloutlets, ventilation systems, alarmsystems and the installation of theAtmospheric Revitalisation Rack(ARS), augmenting the RussianVozdukh system in the Zvezda livingquarters. Racks for tool andexperiment stowage were alsoinstalled. Because of massconsiderations, Destiny was launchedwith only five of its 24 racks installed.Destiny's first science rack – theHuman Research Facility – came upon the next Shuttle visit. The modulealso carried only a basic set ofsoftware, to be upgraded in orbit.

By the time STS-98 departed,ground controllers declared Destinyto be in excellent shape. The onlyproblem was a baulky pump in theARS carbon dioxide removal system.

Jones and Curbeam made theirsecond EVA on 12 February. Ivins usedthe Shuttle arm to move PMA-2 fromits temporary Z1 position to Destiny’send port, with visual cues providedby Jones and Curbeam. It is now theprimary docking port for Shuttlevisits.

Jones and Curbeam installedinsulating covers over the pins thathad held Destiny in place duringlaunch, attached a vent to part of thelab's air system, fixed wires, handrailsand sockets on the exterior to helpfuture spacewalkers, and attached abase for the Station’s robotic arm,scheduled for launch in April.

They connected several computerand electrical cables between the

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station update

Do You Want to See the Space Station?

Then go to http://www.heavens-

above.com/ and it will show you

when the Space Station is next visible

from your location.

The Expedition-1 crew (in blue) greet their STS-98visitors, 9 February.

docking port and Destiny, unveiledthe lab's 51 cm-diameter, optical-quality window and attached anexternal shutter.

While the EVA was underway,ground controllers sent commands tobegin spinning and testing the fourlarge 6600 rpm Control MomentGyroscopes in the P6 Truss sectiondelivered by STS-92. They areoperated by electronics insideDestiny. On 13 February, they tookover control of the Station'sorientation from the thrusters,conserving precious propellant. Onlytwo are required for full control.Control was handed back and forthduring the week as tests continued.

Jones and Curbeam performedtheir third EVA – and the 100th in USspace history – on 14 February. Theyattached a backup S-band antenna toZ1, checked connections betweenDestiny and its docking port,deployed a cooling radiator on P6,inspected solar array connections,and tested the ability of aspacewalker to carry an immobilecolleague back to the Shuttle airlock.

On the final day of dockedoperations, 15 February, the crewstransferred 1.3 t of equipment andsupplies into the Station, includingwater, food, spare parts, a spareVozdukh carbon dioxide removalsystem for Zvezda, a spare computer,clothes and movies. Some400 kg of rubbish – usedbatteries, packing materials,empty food containers andother items – was moved intoAtlantis.

The Shuttle also gave theStation its fourth and finalaltitude boost, leaving it 381 km– 26 km higher than before thevisit. Atlantis undocked 16:06 UT16 February after 6 d 21 h 15 m.The hatches had been open for63 h 9 m.

With a new Progress supplyferry due to arrive Zvezda’s aftport, the Station crew had toboard their Soyuz and move itto Zarya’s nadir port. With

at 10:06 UT 24 February and dockedat 10:37 UT to Zarya. It was the firsttime since the crew’s arrival last2 November that the Station had

been unoccupied. They had tospend the next several hoursreopening the hatches andreactivating key environmentaland communications systemsthat had been shut down in theunlikely event they had beenunable to redock, forcing themto come home.

Progress-M44 automaticallydocked with Zvezda at 09:50 UTon 28 February, successfullyusing the Kurs approachsystem. Within 2 hours, thecrew opened the hatches tounload its supplies, includingclothing, spare parts, computersand office gear for this crewand their successors. ■

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ISS Milestones20 Nov 1998: Zarya launch, first ISS element.

4 Dec 1998: STS-88/2A launch, docks Unity Node-1with Zarya 7 Dec. First crew aboard ISS 10 Dec. 3Shuttle EVAs made external connections.

27 May 1999: STS-96/2A.1 launch, docks withUnity/PMA-2 29 May carrying logistics inSpacehab module. Shuttle EVA installs 2 externalcranes. Undocks 3 Jun.

19 May 2000: STS-101/2A.2a Atlantis launch, dockswith Unity/PMA-2 21 May carrying supplies andto perform maintenance (including EVA 22 Mayfrom Shuttle). Undocks 26 May.

12 Jul 2000: Zvezda launch; Zarya/Unity docks with it26 Jul.

6 Aug 2000: Progress-M1-3/1P launch, docks withZvezda aft port 8 Aug carrying cargo/propellant.Undocks 1 Nov.

8 Sep 2000: STS-106/2A.2b Atlantis launch, docks withUnity/PMA-2 10 Sep carrying logistics inSpacehab module. Shuttle EVA makes Zvezda/Zarya external connections. Undocks 17 Sep.

11 Oct 2000: STS-92/3A Discovery launch, docks withUnity/PMA-2 13 Oct. Attaches first Truss section(Z1, with CMGs and Ku-band comms system) toUnity zenith port 14 Oct. 4 Shuttle EVAs makeZ1/Unity connections, attach PMA-3 to Unitynadir, and prepare for future attachments.Undocks 20 Oct.

31 Oct 2000: Soyuz-TM31 launch, Expedition-1 crew(Gidzenko, Shepherd, Krikalev) docks with Zvezdaaft port 2 Nov.

16 Nov 2000: Progress-M1-4/2P launch, docks withZarya nadir port 18 Nov carryingcargo/propellant. Undocks 1 Dec. Redocks 26 Dec,undocks 8 Feb 2001.

30 Nov 2000: STS-97/4A Endeavour launch, dockswith Unity PMA-3 2 Dec. P6 Truss segment withsolar arrays installed in 3 EVAs. Undocks 9 Dec.

7 Feb 2001: STS-98/5A Atlantis launch, docks withUnity PMA-3 9 Feb. US Destiny lab attached

10 Feb; PMA-2 moved from Unity nadir to Destinyforward. ISS attitude control transferred fromZvezda to Destiny. Undocks 16 Feb.

24 Feb 2001: Soyuz-TM31 moves from Zvezda aft portto Zarya nadir port.

26 Feb 2001: Progress-M44/3P launch, docks withZvezda aft port 28 Feb carrying cargo/propellant.

8 Mar 2001: STS-102/5A.1 Discovery launch, dockswith Destiny PMA-2 10 Mar. First MPLM(Leonardo) attached/detached Unity/PMA-3nadir. Expedition-2 crew swaps with #1 crew.Undocks 19 Mar.

Planned12 Apr 2001: Progress-M1-6/4P launch, docks with

Zvezda aft port carrying cargo/propellant.

19 Apr 2001: STS-100/6A Endeavour launch, dockswith Destiny/PMA-2. Second MPLM (Rafaello)attached/detached Unity/PMA-3 nadir, withracks/equipment for Destiny outfitting. UHFantenna and Canadian SSRMS Station robot arminstalled.

30 Apr 2001: Soyuz-TM32 taxi flight. Docks withZvezda aft port. Crew returns in TM31 from Zaryanadir, leaving TM32 as fresh return craft.

8 Jun 2001: STS-104/7A launch, docks withDestiny/PMA-2 18 May. Installs Joint Airlock andHigh Pressure Gas Assembly.

4 Jul 2001: Progress/5P launch, docks with Zvezda aftport carrying cargo/propellant.

12 Jul 2001: STS-105/7A.1 Endeavour launch, dockswith Destiny/PMA-2. Third MPLM (Donatello)attached/detached Unity/PMA-3 nadir, withracks/equipment for Destiny outfitting.Expedition-3 crew (Culbertson, Dezhurov & Turin)swaps with Expedition-2.

25 Aug 2001: Russian docking compartment (DC-1)and Strela boom attached to Zvezda nadir portfor Russian-based EVAs and Soyuz dockings.

6 Sep 2001: Progress/6P launch, docks with Zvezdaaft port carrying cargo/propellant.

Cockrell (left) and Shepherd make the first entrance into Destiny, on 11 February.

Gidzenko at the controls, Soyuz-TM31backed away 100 m from the Station

André-Deshays to Fly

ESA Astronaut Claudie André-Deshaysbegan training on 22 January in StarCity, Moscow for a Soyuz ‘taxi’ missionto the Space Station in October. TheSoyuz escape craft are replaced every6 months by a fresh vehicle piloted bya crew of two, leaving the third seatopen for cargo or astronaut. André-Deshays will fly in the left-hand seatas an engineer. The 10-day flight,organised by CNES, offers 8 daysaboard the Station before returning inthe older Soyuz. CNES is developing aresearch programme using a 100 kgpayload delivered by Progress andSoyuz, and shared between CNES, DLRand ESA. ■

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recent & relevant

Recent & Relevant

Bed-rest in 2001

ESA, together with CNES, DLR andNASDA, will make two European bed-rest studies in 2001 to support humanphysiology experiments in space, withan eye to long-duration travel such asMars missions. These studies keepvolunteers bed-ridden for longperiods to simulate the effects ofweightlessness on the human body.

The first study starts in April witheight subjects kept horizontal for2 weeks at the DLR Institute forAerospace Medicine in Cologne.Measurements will be taken before,during and after, focusing on theeffect of weightlessness on foodintake and metabolism. The studycovers four phases, each representingone of the possible combinations ofposition control (horizontal vs.upright) and dietary control (normaland under-nutrition).

The second study begins in August,with 25 subjects spending 4 monthsat the Institute of Space Medicine inToulouse. This study focuses onphysical deconditioning, muscleatrophy and bone-mass loss as aresult of long-duration inactivity, aswell as testing the effectiveness ofsome drugs and exercise techniques.

Finding volunteers is not difficult –more than 7000 applied!

Both studies are important forhealth care on Earth, includingproblems related to ageing(osteoporosis, nutritional problems) aswell as longer immobility due tohandicap or prolonged illness(cardiovascular problems, muscleatrophy). The clinical implications willbe strongly pursued by ESA and thescientists involved, and further ESAfollow-on studies are planned. ■

Claudie André-Deshays prepares for EVA training atStar City.

ESA’s exerciser is destined for the Station in 2003.

Gerhard Thiele became the first ESAAstronaut to work as a Capcomduring a Shuttle mission, handlingvoice communications between

ESA’s initiative to develop an exercisedevice that combats muscle wastingon long-duration space missions hasnow been approved. The new ESAdevice, based on the patent ofinventor Prof. Per Tesch, who recentlyvisited ESTEC, uses the ‘Flywheel forResistive Exercise’. The approach issimple: the user pulls on a cordattached to two large flywheels, andthen resists as the cord rewinds onthe spinning wheels. This is the mostefficient system yet available, in termsof effectiveness and resourcesneeded, for maintaining astronauts’muscle mass. Counteracting wastageis trickier than might be expected –despite two decades of long flights,no-one has yet come up with a trulyefficient method.

The new device is attractive inseveral ways: a vast amount ofresearch provides a high level of

Staying Healthy

confidence in the technology; it canbe used in many Station locations; awide range of muscles benefits fromit and the effect is high quality.Perhaps most importantly, the highefficiency means that it leaves ampletime for crew training on either thebicycle ergometer or treadmill forkeeping the circulatory systemhealthy. ■

controllers in Houston and the STS-98crew in orbit in February. In March, heplayed a similar role during theSTS-102 mission. ■

ESA Capcom

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Recent & Relevant

Typical APCF crystal growth reactors

In July, on ISS assembly flight 7A.1(STS-105), Space Shuttle Discovery willdeliver ESA’s first microgravitypayload to the Space Station: theAdvanced Protein CrystallisationFacility (APCF). APCF will be installedin the Shuttle middeck carrying sevenexperiments from Belgium, France,Germany, Italy and The Netherlands.After docking, the crew will transferAPCF’s locker to an Express Rackinside the Destiny laboratory. It willbe activated for automatic executionof protein crystal growth sequencesin 38 individual reactors. After some15 weeks, APCF will be deactivatedand transferred into ShuttleEndeavour (STS-108/UF-1) inNovember for return to Earth.

APCF’s flight is being madethrough an arrangement betweenItaly’s space agency (ASI) and ESA. Ina bilateral agreement with NASA, ASIhas provided three Multi-Purpose

Logistics Modules (MPLMs) to NASA,receiving early Station flightopportunities in return. ASI isproviding the APCF flight opportunityas a special gesture to the EMIR-2European Microgravity ResearchProgramme.

Shuttle Endeavour STS-108 will

First ESA Microgravity Payload aboard Station

carry another ESA microgravityexperiment on its 10-day flight to theStation. The materials scienceexperiment on ‘Weak ConvectionInfluencing Radial Segregation’ willbe carried in a Get Away Specialcanister attached to the payload baywall of Endeavour. ■

Belgium (1), France (1), Germany (3),Italy (1) and Sweden (1) in materialscience (3) and fluid physics (4). Twoof the fluid physics experiments havesimilar set-ups to investigate surface-driven flows in a liquid bridge as amodel of the floating zone crystalgrowth technique. The others willcharacterise aqueous and non-aqueous foams. The first materialsscience experiment will look at theinitial crystallisation of silicalite-1. Two

ISS Advanced Training

The first ESA astronauts will begin ISSAdvanced Training in Houston on2 April to become eligible as Stationresidents once assembly of thecomplex is completed in 2006. TheInternational Partners agreed inNovember 2000 that up to four ESAastronauts, three Japanese and aCanadian could take the 1-yearcourse.

The training is organised in blocksof several weeks and located at thevarious Partner training sites, spreadover 18 months. In between theblocks and after completion of thistraining, refresher lessons willmaintain the astronauts’ proficiency.Once assigned to a specific Stationmission (‘increment’) with US andRussian colleagues, an astronaut willthen undertake Increment Training.

During the Station’s current

Maxus-4 Ready to Launch

ESA’s Maxus-4 suborbital microgravitymission is scheduled for launch on29 April from Esrange near Kiruna innorthern Sweden. The flight up to710 km will provide microgravityconditions of better than 10-4 g forabout 12.5 minutes.

The 490 kg scientific payloadcomprises five autonomous moduleswith seven experiments from

assembly phase, the first six primecrews were directly assigned toIncrement Training with theirbackups. The back-up crews will inturn be assigned to the next sixincrements, starting with the 7th. Thisback-up training is equivalent to theISS Advanced Training. Whenassembly is complete, the syllabuswill normalise at Basic Training +Advanced Training + IncrementTraining. ■

silicon-growth experiments will beperformed in mono-ellipsoidal mirrorfurnaces. The first investigates howthe Marangoni convection in the meltof the growing semiconductor can besuppressed by a rotatingelectromagnetic field. The seconduses a piezoelectric oscillator toinduce vibrations in the melt of thegrowing crystal to influence andcontrol the segregation. ■

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Recent & Relevant

As Head of MSM’s new ISSExploitation PreparationDepartment at ESTEC,Jochen Graf has taken overelements of theresponsibilities of FrankLonghurst, the former Headof the Manned SpaceflightDepartment. Since 1 October 2000,Jochen’s responsibilities cover all thetasks leading to the regular,continuous use of ESA’s contributionto the Space Station, development ofthe European Control Centres andTrainers, the preparation of flightoperations and related activities, andengineering support for DMS-R andERA. In addition, his department isinitiating commercialisation activitiesfor the Station. The study activities forfuture developments in mannedspaceflight also reside within thisdepartment.

After studying electricalengineering in Berlin, Germany,Jochen began his professional careerin 1966 with Siemens (Berlin),followed by 4 years with Ampex(California). He entered themanagement field as Project

Manager for DataManagement Systems inMedicine with GSF(Munich), before joining ESAin Noordwijk in 1974. Hewas initially responsible forSpacelab flight operations, aposition later expanded to

cover ground operations andsoftware. In 1985, he joined the earlymanagement team for the ISS. HisDivision covered system definition,operations and software tasks. Withthe introduction of Russia into theSpace Station programme, hebecame additionally responsible forthe development of the DataManagement System for the RussianZvezda module.

Over the last 5 years, he has builtup extensive experience innegotiating with the managementteams of the Russian partner atagency and industry level. Thisincluded the conclusion of a long-term cooperative agreement onintegration of ESA’s AutomatedTransfer Vehicle with the RussianSegment and management of itsinitial implementation. ■

ESA’s New ISS Exploitation Preparation Department

MPLM Donatello arrives in the Space Station ProcessingFacility at the Kennedy Space Center.

Final MPLM Delivered

Italy’s third and last Multi-PurposeLogistics Module (MPLM), Donatellomwas delivered on 1 February to theKennedy Space Center to beginpreparations for ferrying hardwareand supplies to the Space Station.MPLM is making a uniquecontribution to Station logisticsbecause it is the only module capableof delivering complete payload racks.It is part of a bilateral arrangementbetween ASI and NASA, whereby ASIhas exclusive access to certain SpaceStation utilisation rights in exchangefor the supply of the three MPLMs toNASA.

ESA developed and delivered theEnvironmental Control and Life

Support (ECLS) equipment for theMPLMs and Columbus, in exchangefor which ASI provided the primarystructures for both vehicles. In thisway, each agency was relieved ofdeveloping significant portions ofmajor subsystems, thereby savingtens of millions of Euros.

Details of the MPLM/ECLS can befound in ESA brochure BR-143 and atthe website http://esapub.esrin.esa.it/br/br143.htm

Leonardo was delivered to KSC on3 August 1998 for its debut in March,on Shuttle mission STS-102/5A.1.Raffaello arrived on 2 August 1999,and will fly on STS-100/6A in April.Donatello is aiming to debut onSTS-105/7A.1 in July. ■

MFC Status

ESA’s Microgravity Facilities forColumbus (MFC) programme is nowwell into its Engineering Model (EM)phase. Testing of Biolab’s EM isunderway. A crew evaluation by ESAAstronauts Claudie André-Deshaysand Pedro Duque confirmed that thefacility offers easy operation andmaintenance in orbit.

The Fluid Science Laboratory EM iswell advanced and integration isalmost complete. Recently, ESAconcluded an agreement with theCanadian Space Agency to receive aMicrogravity Vibration IsolationSystem (MVIS) to maintain a goodmicrogravity environment aboard theStation, as requested by Europeanscientists.

The Materials Science Laboratorywill be integrated into the NASAMaterials Science Research Rack-1 forlaunch on UF-3 in 2004. EMintegration is almost complete. Acrew evaluation confirmed the designfor the on-orbit exchange of furnaces.

Development of the EuropeanPhysiology Modules began after theother facilities, but bread-boards havenow been manufactured. ■

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IntroductionESA’s Atmospheric Reentry Demonstrator (ARD)was a major European step towards futurespace transportation vehicles. For the first time,Europe flew a complete space mission –launching a vehicle into space and recoveringit safely. ARD was launched on 21 October 1998aboard Ariane-503, reaching a maximumsuborbital altitude of 830 km before splashingdown in the Pacific Ocean within 5 km oftarget.

During the mission, critical data such aspressure, temperature and vibrationwere recorded from more than 200sensors distributed throughout thevehicle. The measurements werestored on two recorders as well asbeing transmitted to ground(Libreville in Gabon) and airborne (ARIA 1 and2 aircraft) stations after Ariane separation andfrom before reentry through to landing. ARDwas recovered by the French Navy andreturned to prime contractor Aerospatiale inBordeaux for detailed inspection.

ARD’s main objectives were to:– test and qualify reentry technologies and

flight control algorithms under actual flightconditions,

– obtain inflight validation of design concepts,hardware and system capability to managecompromises between various technologies,

– validate aerothermodynamic predictions,– qualify the design and the materials of the

thermal protection system,– assess the performances of the navigation,

guidance and control system,– assess the performances of the parachute

and recovery system,– study radio communications during reentry,– to demonstrate industrial capability within a

tight schedule and limited budget.

The preliminary post-flight analysis showedthat everything worked well and identified thefirst differences between the predicted valuesand the flight data on the reentry onset,aerodynamic trim and side-slipangles, roll and drag commands,heating rates, high-altitudeplasma frequencies, attitudecontrol system propellantconsumption and parachute opening loads.

The trajectory prediction was based onestimated injection parameters from

Ariane-5, with a conservative approachtowards the heating rates. The first

step of the analysis was therefore touse the actual flight parameters to

rebuild the trajectory model as inputfor further detailed analysis. After that, thepre-flight prediction was updated for eachtechnical discipline and then compared withthe flight data.

The more detailed analysis aimed atunderstanding the deviations in detail as wellas to update the simulation/prediction tools. Afinal rerun of those tools was performed tovalidate the modifications.

Aerodynamics/aerothermodynamicsARD’s hypersonic trim behaviour wasconsistent with a centre of gravity offset of3-4 mm, explained by propellant consumptionand heatshield pyrolysis. The systematic flightdata analysis of the relative pressure dataconcluded that real-gas effects were alsoobserved below Mach 10, and this wasconfirmed by additional Computational FluidDynamics (CFD) analysis.

The heating rates were difficult to assessbecause a thermocouple just below ARD’s skinfailed to return data in the 700-800°C range.

MM ission Aission Accccomplished omplished Final Report on the Atmospheric Reentry Demonstrator

ARD was a major step towardsfuture space transporationvehicles...

Mike J. SteinkopfARD Postflight Study Manager, D/MSM, ESTEC, Postbus 299, 2200 AG Noordwijk, The NetherlandsEmail: [email protected]

the 1-sigma value.It was found that an

attitude offset (time-shifting of bank anglemanoeuvre and ahigher bank anglevalue) appeared with ahigher load factor.These discrepanciescan be explained byuncertainties in theatmospheric densitymodel and in the MassCentre of gravity andInertial (MCI) model.After updating thesemodels, the centre ofgravity location andthe normal and axialforce coefficients were

found to be coherent with the flightdata.

The propulsion analysis revealedhigher consumption than expectedbecause of the centre of gravity offset,which required increased thrusterfirings during reentry in order toreduce the range and to compensatefor wind perturbation. Most of thevelocity (hence position) error wasseen in the altitude range of 12-11 km, where there were largeuncertainties in the north-south windgradients. Improving the atmosphericmodel (particularly the density) isdeemed necessary.

Communications and plasmaThe communications and GlobalPositioning Satellite (GPS) datashowed a very sensitive receiver. TheGPS data covered the launch, orbitaland reentry phases. Inflight validationof the new ‘code-only’ mode(developed to enhance fastacquisition and robust tracking) wassuccessful. Even ARD’s rotation underthe parachute was clearly seen in theGPS data.

The GPS data contributedsignificantly to analysing theformation of plasma during reentry. Aminimum of nine geometricallydistributed GPS satellites werepermanently tracked and providedestimates of volumetric attenuation

However, the predicted peak heatingrates were coherent with the flightdata when chemical equilibrium isassumed. For the low heating rates,non-catalytic predictions wereconfirmed by flight data. These trendshave been well reproduced byCFD/engineering methods. The lowcatalytic effects at high altitude wereconfirmed, whereas the pyrolysiseffects close to peak heating inhibitedthe low catalytic behaviour, andresulted in heating rates close tochemical equilibrium conditions.

ARD’s rear cone section providedanother surprise: the overheatingcould not be reproduced by thecurrent CFD analysis. The cause mightbe the effects of air thermochemistry,or there might have been anintermediate regime between thelaminar and turbulent flows that isincorrectly described by currentturbulence models.

Thermal Protection System (TPS)All TPS materials were carefullyinspected, demounted and thenmechanically tested. Finally,temperature measurements wereanalysed and compared with thedesign loads.

The main heat-shield material,Aleastrasil, confirmed the low surfaceerosion (0.1-0.3 mm) and enabled anupdate to the thermal properties data

set, helping to reconstruct the thermalflux history. The conical body materialssamples – Flexible External Insulation(FEI) and Carbon Silicon Carbide(C/SiC) – showed no flightdegradation (no surfacecontamination through the ablativeAleastrasil or sea water impact). Thethermal loads on ARD’s leeward sidewere significantly lower thanexpected and well below FEI’s limit;C/SiC’s maximum of 940°C meant thatthe samples were not fully tested. TheFEI suffered severe damage duringrecovery operations anddemonstrated that specialprecautions (e.g. rigid covers) arenecessary. There was no damage tothe C/SiC samples themselves or tothe attachment bolts from launch andlanding stresses. The surfacemorphology and oxidation-protectionlayers were unchanged. ARD providedonly a limited demonstration of FEIreusability because capsules naturallysuffer more severe landing conditionsthan winged vehicles.

Guidance, navigation and control The recorded Inertial MeasurementUnit (IMU) and radar data werecarefully examined to build thereference trajectory. The performanceof ARD’s inertial navigation was rathergood and the orbit injection errorswere less than predicted and within

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ard

ARD’s heatshield before (right) and after the flight.

with a minimum sampling of 1 Hz andlow-noise measurements. The analysisshowed:– highly asymmetrical attenuation

effects, of 180-300 s duration,– signals from the forward satellites

are lost first and reappear last,– partial reacquisition of GPS signals

was observed.

Plasma analysis was divided into:

Phase A: axisymmetric calculationsaround a windward equivalentgeometry in order to select thethermochemical modelling to beused for 3-D calculations,

Phase B: 3-D calculations at threealtitudes with comparisonsbetween calculations andmeasurements on plasmafrequencies at the reflectometerposition and plasma attenuationsof TDRS and GPS links.

There was relatively goodagreement between the calculationsand measurements at altitudes of85 km and 46 km. The calculatedplasma frequencies and TDRS linkattenuations were clearly greater thanthose measured at an altitude of61.5 km.

The plasma effect on radio links isperfectly correlated with thefrequency (L & S-bands).

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As a consequence of thecommunications analysis, thefollowing additional instrumentationis recommended :– windward and leeward

reflectometers to measurelongitudinal and circumferencialplasma evolution,

– multi-frequency reflectometers forobtaining partial plasma frequencyprofiles and collisional frequenciesor plasma thickness measurements.

ParachutesThe effect of the overall studyapproach for the parachutes led to thefollowing basic results.

Inflation loads: drag area growthformulae are adequate.

Descent rate - dragarea calibration: 80%is the appropriatescaling to be appliedfor the 20% porosityconical ribbon droguechute efficiency incapsule wake fields.Deployment analysis:simplified 1-D Codesare fully applicable forthe deploymentanalyses. A 10% safetyfactor should be usedfor estimating stretch-velocity (and snatchforce).Attitude dynamics:suitability of thesimulator for stability

prediction in 2-D (pitch) analysis;unsuitability of the simulator forcomplete 3-D attitude dynamicsanalyses.

Major simulator improvementsrequired include:– dynamic tests of suspension lines,

characterisation of non-linearityand viscoelasticity have to beimproved,

– parachute aerodynamics,– detailed model of attachments,

including characterisation of thestiction-friction at swivel axes.

Lessons Learned and ConclusionsARD’s maiden flight was, as Europe’sfirst step in reentry technology, a totalsuccess. Nevertheless, the detailed‘autopsy’ shows that completemastery of reentry is still a challengeand should include vehicles ofdifferent shapes and adoption ofpost-flight analysis recommendations.Telemetry recording is critical forunderstanding the reentry events. Theimpact of recovery operations mustnot be under-estimated.

Experimental flight vehicles arecritical for understanding the reentryprocess. ARD was the first step andfuture tests such as X-38/V201 willbuild towards future spacetransportation systems.

For further technical details, readerscan consult the ARD post-flight ftpserver: ftp.estec.esa.nl; userid: ard-pfas;password : ard p0st (‘zero’ not ‘o’)’ �

ARD major events:predicted valuescompared with the post-flightreconstruction. H0 isthe time of Ariane-5main engine ignition.Times are in h:min:s

EVENT PREDICTION FLIGHT Measurement (time from H0) (time from H0)

AR-5 separation 00:12:00/218 km 00:12:00/216 kmInjection orbit 6798.5 km 6802.4 km

(semi-major axis/inc.) 5.753° 5.754°Libreville visibility 00:17:09 - 00:27:39 00:17:38 - 00:29:20TDRS signal received 1:08:34 1:09:10ARIA 1 visibility 1:15:42 - 1:20:30 1:15:34 - 1:23:25Start of reentry (120 km) 1:18:58 1:19:06

(longitude shift: 60 km)Acceleration (max.) 3.2 g 3.7 gTrim 22° 20°Roll angle command (max.) 105° 110°Blackout 90 - 42 km 90 - 43 kmCrossrange 68 km 67 kmARIA 2 visibility 1:22:05 1:25:02 Parachute opening 1:28:14 / 14 km 1:28:00 / 14 km

horizontal accuracy 3 kmSplashdown 1:42:55 1:41:19

sink rate : 6.7 m/s sink rate: 7 m/simpact: 7 g impact: 7.3 g

accuracy: 4.9 kmEnd of mission 1:47:55 1:46:23

ARD’s predicted flight events

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15th ESA Symposium on European

Rocket and Balloon Programmes and Related

Research

Please contact for information:ESA/PAC SecretariatESTEC

Postbus 299

2200 AG NoordwijkThe Netherlands

Tel.: +31.71.565-5613Tel.: +31.71.565-3262

Fax: +31.71.565-3042

Symposium e-mail address: [email protected]

Symposium Web address:http://www.cnes.fr/colloque

On StationISSN 1562-8019

The Newsletter of ESA’s Directorate of Manned Spaceflight & Microgravity

This newsletter is published by ESA Publications Division.It is free to all readers interested in ESA’s manned

spaceflight and microgravity activities. It can also be seenvia the website at http://esapub.esrin.esa.it/

For a free subscription or change of address, please contact Frits de Zwaan at [email protected]

ESA Publications Division/DG-PESTEC, Postbus 299, 2200 AG Noordwijk, The Netherlands.

Fax: +31 71 565-5433

Editors: Andrew Wilson ([email protected]) and Brigitte Schuermann ([email protected])

Contributing Writer: Graham T. BiddisDesign & Layout: Eva Ekstrand & Carel Haakman

on station 5 - esa

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