discussion of next term · enae 483/788d - principles of space systems design u n i v e r s i t y o...

Next Term’s ProjectENAE 483/788D - Principles of Space Systems Design

U N I V E R S I T Y O FMARYLAND

Discussion of Next Term• Final design project information• Discussion of final exam• Discussion of grading for group projects• Other useful information

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© 2013 David L. Akin - All rights reservedhttp://spacecraft.ssl.umd.edu



Notes

• Due date for project 5 postponed to time of final exam Monday 12/16

• Slides for Tuesday’s class (Sensors and Actuators) posted to Piazza site

• Reminders:– Final exam limited single 8.5”x11” sheet of notes– Bring a calculator– Given honest attempt, final will only be counted if it

improves overall grade

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ENAE 483/788D Final Exam Questions• Orbital mechanics• Rocket performance• Reliability• Life support• Power systems• Structural design• Thermal analysis• Cost analysis• Propulsion systems• Systems engineering

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Grading Rubrik for Group Projects

• 10 - essentially perfect• 9 - excellent• 8 - very good• 7 - good• 6 - okay• 5 - minor deficiencies• 4 - significant deficiencies• 3 or below - major deficiencies

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Fall Term Project Organization

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B11

B10

B9

B8

B7

B6

B5

B4

B3

B2

B1

A11

A10

A9

A8

A7

A6

A5

A4

A3

A2

A1

C11

C10

C9

C8

C7

C6

C5

C4

C3

C2

C1

D11

D10

D9

D8

D7

D6

D5

D4

D3

D2

D1

E11

E10

E9

E8

E7

E6

E5

E4

E3

E2

E1

Systems Engineering

Crew Systems Power, Propulsion, and Thermal

Loads, Structures, and Mechanisms

Avionics and Software



Grades

• Scores for each project will be mailed to each team member

• Project scores consist of 0-10 assessment in each of ~10 categories plus comments

• Your course grade is made up primarily of your grades from each project, plus the problem set and final (if helpful)

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Sample of Project Grading Feedback

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Systems'Architecture 10 7 Considered,'but'minimally'presentedLevel'1'Requirements 10 8

Requirements'Flowdown 10 8

Didn't'even'include'placeholders'for'other'requirements'(e.g.,'avionics,'comm);'some'strange'choices'on'where'to'put'requirements'(e.g.,'volume'"suitable'for'human'habitation"'as'an'LSM'requirements)

Work'Breakdown'Structure 10 8 Like'that'you'make'mockup'operations'into'a'dedicated'specialty

Concept'detail'and'feasibility 10 9Excellent'concept'overall;'could'have'had'more'detail'in'interior'and'systems

CAD'quality 10 9

Good'work'on'overall'images,'use'of'human'images,'provision'of'airlock'and'docking'ports,'dimensioned'drawing!;'minimal'interior'details,'no'threeSviews

Functional'breakdown/trades 10 9 Good'research'for'SOA'from'prior'systems

Draft'concept'of'operations 10 6 Only'implicit'in'LIRP'discussions

Slide'package'quality 10 7Text'generally'acceptable'but'smaller'than'necessary;'text'too'small'in'tables

Evidence'of'critical'thought 10 9 good'detail'(e.g.,'airlock'sizing)

Bonus'for'extra'effort 4 really'liked'the'CADOther'positive'comments 2 program'deliverables'chartOther'negative'comments S1 didn't'have'citation'for'image'used'on'page'30 average high lowOverall'score 100 85 64.8 85 51



A (Revised) Vision for ENAE484• Design a cislunar space habitat capable of

providing data on long-term spaceflight prior to human Mars missions– Radiation– Effects of hypogravity

• Phased approach to utilization– Phase 1: early microgravity– Phase 2: artificial gravity– Phase 3: full lunar/Mars mission simulations

• Each phase should take no more than one additional heavy-lift launch

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Concept of Station Operations• Minimum functional habitat inserted into lunar distant

retrograde orbit to support Asteroid Redirect Mission• Decision on moving to alternative point in cislunar

space for long-term biological studies (EM L2? leave in DRO?)

• Addition of elements to allow rotational partial gravity • 6 month studies of physiological effects of lunar,

Mars, other gravity levels• Addition of elements to allow extended autonomy for

Mars mission simulation• Performance of full Mars mission (with/without

partial gravity en route?)

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Level 1 Rqmts: Cislunar Habitation• The system shall be capable of operation at any

Earth-Moon libration point, low lunar orbit, or a distant retrograde orbit

• The system shall support crew for nominal 30 day missions

• The system shall be compatible with Orion and commercial crew vehicles

• The system shall be designed for resupply to support multiple missions

• Phase 1 habitat shall be capable of supporting Asteroid Redirect Mission in lunar DRO

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L1 Rqmts: Partial Gravity Simulation

• The system shall be upgraded to be rotated to provide artificial gravity up to one Earth g

• The system shall be upgraded to the extent possible using surplus hardware (e.g., spent upper stages, empty logistics modules) and additional hardware requiring no more than one dedicated HLLV launch

• The system shall support up to six-person crews for periods up to six months without resupply

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L1 Rqmts: Mars Mission Simulation• The system shall be capable of simulating a

complete conjunction-type Mars mission (~1000 days) without nominal resupply

• The system shall be capable of differing gravitation levels throughout the simulated mission

• The system shall provide some means of simulated EVA at Mars gravity during the appropriate parts of the simulation

• The system shall be upgraded with additional hardware requiring no more than one dedicated HLLV launch

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Top-Level WBS for ENAE 484

• Develop a detailed systems design for an evolutionary cislunar habitat program– Microgravity habitat– Variable gravity habitat– Full Mars mission simulation capability

• Perform experimental verification of habitat design– 1g simulations– Underwater simulations of 0g, lunar, and Mars

conditions

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Data from Preference Survey

• Strongly focused on experimentation - 12• Mostly focused on experimentation - 19• Equal experiment and analysis - 3• Mostly focused on analysis - 7• Strongly focused on analysis - 1

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Expectations for ENAE484

• Single, coherent, integrated project with both analytical and experimental content

• Analytical development of systems design is critical for course pedagogy, context for experimentation

• Every student is expected to make technical contributions to the project

• Grades will also reflect efforts on supporting organization and logistics of project

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Pedagogical Implications of 483/484• Senior capstone design sequence

– Apply principles of systems engineering to large real-world application

– Perform full end-to-end mission architecture and vehicle design analyses

– Utilize tools gained from four years of Aerospace Engineering education

• Use mission design aspects as context for experimental testing

• Take advantage of unique assets and expertise at the University of Maryland

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Clarke Station (ENAE 484 Spring 2001)

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Phoenix Station (ENAE484 Spring 2006)

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Habitat Configuration - Team B1

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Project Design Challenges

• Establishment of canonical habitat design• Definition of science requirements for long-term

study of variable gravity habitation• Establishment of reference program conops

(locations for station, transport requirements, timelines for development and testing phases)

• Development of system architecture (launch vehicle interfaces; transportation to cislunar space; accommodation of transport and logistics systems)

• Definition of component systems (e.g., power, propulsion, thermal control, avionics, life support)

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Project Design Challenges

• Detailed design and analysis of structural components

• Definition of logistics requirements and servicing system

• Design of habitat layout and accommodation of both microgravity and planetary gravity levels

• Identifying technology readiness levels and systems with particular development needs

• Program scheduling and cost estimation

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Habitat Design and Selection Concept• Start with best designs from Fall mini-teams• Develop CAD models of appropriate complexity• Perform virtual reality “walk-throughs” using SSL

Oculus Rift system• Downselect to 2-3 canonical designs

– Drop clearly inferior designs based on subjective evaluations from walk-through

– Modify and create hybrid designs taking best features from several concepts

– Evaluate using questionnaires and relative rankings to define designs for hardware implementation

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Planning for Experimental Studies

• Identify experimental objectives for both 1g and underwater systems

• Complete designs for experimental set-ups; evaluate against program budget

• Order components and perform modifications to existing habitat systems

• Establish test protocols and matrices; identify test subjects; verify human use approvals

• Perform human testing to evaluate habitat designs• Use results to modify system design as necessary

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1-G Testing: ECLIPSE Habitat

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ECLIPSE Details and Capabilities

• Developed as minimum functional habitat element for lunar program under NASA ESMD funding in 2009-2010

• Two floors, 3.6 m diameter– 20 m2 floor area– 40 m3 habitable volume– Also incorporates external airlock module

• Little used for last three years; will require basic cleaning and cosmetic repair to use as-is

• Can be stripped to test new internal layouts

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1-G Testing: HAVEN Module• Two story habitat module (currently

limited to one level)• Modular removable wall sections

(8x45° sectors)enable total reconfiguration of the habitat

• Multiple vertical hatch locations enables a wider variety of layouts to be implemented

• 5m outer diameter provides 20 m2 floor area and 40 m3 in current configuration; double if upper level is added

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Haven Initial Outfitting

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HAVEN Outfitting

• HAVEN is designed to be highly modular and easily reconfigurable– Each interchangeable wall section is separately wired

for power and lighting– Widespread use of pegboard panelling for quick

additions of surface-mount items

• Designed with dual hatches to upper level (centerline and next to the wall) for comparison

• Potential access to storage volume between floor joists

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1G Simulation: Short Term

• Single-task operations, e.g.– Maintenance– Mission operations, e.g. telerobotic operations– Stowage operations– Food preparation and eating

• Accommodations for multiple crew in cooperative or independent tasks

• Video/audio monitoring and comm to simulated mission control (real-time and time delay)

• Controllable data delay in comm loop

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1-G Simulation: Medium Duration

• “A day in the life...”• Select volunteers for mission segment simulations

up to a full day• May simulate portion of sleep cycles, but will not

stay overnight (code issues)• Set up “mission control” next-door in Neutral

Buoyancy Research Facility to monitor and interact• Note crew real-time comments on habitability

issues; use post-test questionnaires and TLX assessments as quantitative metrics

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Expanded Options for 1-G Testing• Multi-day simulations

– Would require work to meet code (as per UMd Fire Marshall)

– Concomitant requirement for round-the-clock “mission control” for safety, monitoring, and data collection

• Interaction with robotic systems– UMd-developed manipulator systems (wall mounts

already built into HAVEN walls)– Wheeled mobility bases inside hab

• Facility upgrades– Add second floor to HAVEN– Move ECLIPSE to mate to HAVEN⇒CHELONIA

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Habitability Evaluation• Goal: identify a rigorous process to define habitability • Construct parametric curves based on experimental evaluations

of low to medium fidelity mock-ups for both 1g and underwater testing

• Potential analytical tools– AHP(Analytic hierarchy process)– NASA TLX

– Cooper Harper– Fitt’s Law derived evaluations

• Extrapolate results to cover a broader spectrum of habitat configurations and dimensions

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UMd Neutral Buoyancy Research Facility

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Underwater Habitat Mockup

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Underwater Habitat Three-View

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18 ft

14.5 ft

8 ft8 ft

13.4 ft



End Dome of Underwater Hab

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Underwater Habitat Mockup Details• Truss construction from 1.5in schedule 40 PVC

plumbing and commercial fixtures• One endcap with standard Common Berthing

Mechanism hatch modeled• Capable of being tested in horizontal or vertical

orientation• Use large-cell net or polyethylene panels for external

walls if desired• Can install rigid fiberglass panels for internal

structures as necessary• Capable of expansion (e.g., airlock simulator,

additional module length, interconnecting modules)

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Underwater Habitat Testing• Component-level testing, e.g.

– Traverses between decks (ladders, stairs, other)– Partial gravity neutral body posture?– Reach and force envelopes?– Workstation designs

• Habitability testing, e.g.– Distributed tasks (waterproof tablets at various work

stations require test subject to maneuver around station interior)

– Standardized maintenance task with variable ballasted component elements

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Underwater Habitat Applications

• Microgravity operations and layout assessment• Ballasted partial gravity operations and layout

assessment• Vertical vs. horizontal habitat comparison• Full high-resolution, high-rate motion capture• Rich infrastructure of monitoring cameras, two-

way audio communications with test subjects• Ability to perform basic microgravity/partial

gravity anthropometric testing

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Extended Options for UW Testing• Interior interactions with free-fliers or

manipulators• Use of Qualisys 12-camera

motion tracking system tomonitor/quantify test subject motions

• Underwater six-axis force-torque sensor to quantify applied loads; Qualisys system to measure reach envelope

• Underwater suit (MX-3) and suit simulators for EVA operations

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Spring 2014 Tentative Schedule• Jan. 28 - first day of ENAE484• mid Feb. - requirements/trade study review; verify

all long-lead items on order• early March - Preliminary Design Review• mid-March - outline of final report due• early April - review of test sites and planning for

human factors testing• late April - Critical Design Review• May 13 - final report due• June 17-19 - RASC-AL competition (Cocoa Beach)

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ENAE484 Specialty Teams

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Avionics and Software:Colin AdamsonJennifer KingRubbel KumarMihir PatelMichael SchafferKristy Weber

Mission Planning and Analysis:Matthew FeeneyKurt GonterMatthew HorowitzDouglas KleinSahin KunnathPegah PashaiKyle Zittle

Power, Propulsion, and Thermal:Charl DuToitIrving GarciaChandan KitturBrooks MullerMichael ShallcrossDaniel TodaroMazi Wallace

Crew Systems:Ashok BhattaraiIrene Borillo LlorcaKevin FergusonSamuel GaraySarin KunnathOliver OrtizMark Schneider

Systems Integration:Bianna BrassardRajarshi ChattopadhyayKyle CloutierAlexander DownesDonald GregorichEdward LevineAtin MitraNitin Raghu

Loads, Stuctures, and Mechanisms:Matthew AdamsMichael KantzerBenjamin MellmanRyan MoranWilliam OuyangBrandyn PhillipsCody Toothaker

discussion of next term · enae 483/788d - principles of space systems design u n i v e r s i t y o...

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