1. H ybrid P ropellant M odule H ybrid P ropellant M odule Block 2 Update 12/2/2001 Pat Troutman LaRC Spacecraft & Sensors Branch p.a.troutman@larc.nasa.gov Block 2 Update 12/2/2001 Pat Troutman LaRC Spacecraft & Sensors Branch p.a.troutman@larc.nasa.gov

2. Future Assumptions: 2015 and Beyond Low Earth Orbit (LEO) & Beyond: NASA/International Space Exploration NASA has deployed a gateway facility at the Earth-Moon L1 point. ISS has evolved into a transportation hub & servicing facility. Commercial Commercially viable in-space manufacturing of pharmaceuticals and materials resulting from ISS research has begun on automated and crew tended platforms A commercially owned upgraded Shuttle features a payload bay passenger module for commercial crews and other paying passengers. The first hotel in space (based on the NASA gateway facility and catering to the elite) has opened in LEO. Military The United States military dominates the space theatre. Available Earth-to-Orbit Transportation: Upgraded Shuttle - operations overhead cut in half with the same performance. Large reliable ELV - 35,000 kg to LEO with a 6 meter shroud. Inexpensive ELV - weekly launch of 10,000 kg of logistics to LEO. Revolutionary RLV eventually replaces weekly ELV launches.

3. HPM Level 1 Requirements The HPM shall support commercial, NASA and DOD missions. The HPM and associated elements shall be designed, built, inspected, tested, and certified specifically addressing the requirements for human-rating. The HPM shall be reusable The HPM shall be designed for an operational lifespan of ten years. The HPM shall have on-orbit maintainable (via EVA and robotics) avionics. The HPM shall be capable of autonomous operations for all systems The HPM shall accommodate automated rendezvous and docking with other vehicles. The HPM shall provide long-term storage of Lox, LH2, & Xenon for use by chemical and electric propulsion systems The HPM shall be capable of being refueled on-orbit

4. HPM Deployed Position (Dia = 4.8m) Deployed Docking/Fluid Transfer Ring (2) HPM Configuration HPM Upper Stowed (Dia = 4.5m) PV Arrays in Stowed Position (44m 2 total) Trunnion Fittings (4) Grapple Fixture ORUs Stowed Deployed Access Hatches Stowed Docking/Fluid Transfer Ring (2)

5. Tank Supports Radiators (2) HPM Interior Layout

6. HPM Structural Layout with Tanks LH 2 Tank Properties: Volume = 65.8m 3 Chemical Mass = 4455 kg Tank Mass = 162 kg LOX Tank Properties: Volume = 24.19m 3 Chemical Mass = 26,723 kg Tank Mass = 48 kg Xe Tank Properties: Volume = 3.85m 3 Electric Mass = 13,552 kg Tank Mass = 10 kg

7. HPM Overall Dimensions & Capacities 6.35m7.75m 1m 3.15m Once deployed the docking rings can extend to 0.5m A A B B

8. Radiators Lower debris shielding LOX tank walls and insulation Place holders for radiation and thermal protection Keel fitting Lower HPM Cross Section The lower section of the HPM uses the Whipple debris shielding similar to existing portions of the ISS. This type of shielding incorporates a constant outer diameter allowing access to the subsystems. The lower primary structure consists of the inner most wall of the debris shielding tied into the stringers that run the length of the lower section. The vacant space will be filled with thermal protection layers.

9. Upper section deployed debris shield I-Beams LOX Tank Wall and Insulation (2.54cm thk) Radiation Shielding Place Holder Upper HPM Cross Section The upper section of the HPM uses the deployable debris shielding similar to that demonstrated on the Mars Trans Hab Module. Although heavier than the simple Whipple type shielding, it can withstand impacts from much larger diameter micrometeoroids and orbital debris. The upper structure is similar to the lower section but just at a larger diameter.

10. A A Section AA LH 2 Tank Properties: Volume = 65.8m 3 Surface Area = 86.0m 2 Barrel Length = 4.44m Inner Diameter = 3.68m LOX Tank Properties: Volume = 24.19m 3 Surface Area = 40.1m 2 Barrel Length = 1.27m Inner Diameter = 3.30m Intl. Berthing Docking Mechanism (IBDM) 1 (2) Max Dim’s: 1.4m dia x 0.25m thick Hatch Pass Through: 0.80m 1 IBDM in development, estimated year 2005 operational date PV Drive Location (2) Avionics ORUs Flywheels Cryogenic Coolers (2) – The other Cooler is located between the LH2 and LOX Tank Fluid Transfer Line Routing Xe Tank Properties: Volume = 3.85m 3 Surface Area = 12.10m 2 Upper Deployed Debris Shield (Dia = 4.8m - 0.305m thick)Y PV Array Area = 12m 2 per side Radiators (2) Lower Debris Shield (0.101m thick) Tank Supports (Similar for LOX tank) Supporting Structure (0.305m I-Beams) FTI 14m

11. HPM Structures Technology Summary

12. HPM Systems

13. HPM Guidance, Navigation & Control System Functional Description: Maintain attitude in free flight mode and during autonomous docking operations in LEO,GEO and L1 environments. Key Performance Requirements: Hold attitude to within +/- 5 degrees of TEA during LEO/GEO parking orbit mode Position and hold attitude to within +/- 0.5 degrees during docking operations Provide attitude and position knowledge in support of automated docking operations Design/Technology Description: Attitude Control – Flywheels used to rotate and maintain attitude. The flywheels are also integrated with the power system as an energy storage device. Position & Attitude Knowledge - The attitude, attitude rates, position, and velocity, and Sun pointing of the HPM would be determined using an enhanced Microcosm Autonomous Navigation System (MANS) sensor suite, comprising of Star Sensor and Earth sensor with IMU as back-up. MANS suite can currently provide 100m position information, 0.03 deg attitude information, and is light and uses little power. While MANS has been used for Earth orbits, it’s extension to deep space applications is new technology. Autonomous Rendezvous & Docking - The Autonomous Formation Flying (AFF) sensor would be used by the HPM and other docking vehicles for precision relative navigation during automatic rendezvous and docking. The AFF can provide 1 cm position accuracy, 0.1mm/s relative velocity, 1 arc-minute attitude, using 1W power and weighs less than 2 kg. This technology needs to be demonstrated on-orbit. AFF can replace or enhance GPS and retro- reflector based concepts.

14. HPM Guidance, Navigation & Control (Schematic) HPM Attitude Dynamics HPM Translational Dynamics MANS Star Camera Earth Sensor IMU HPM Attitude Controller and momentum manager Communications subsystem To Earth/Moon or other vehicles for coarse nav information Attitude and attitude rates Position and velocity Flywheel Flywheel momentum Flywheel torque Steering Law Flywheel torque command Power subsystem AFF sensors Docking Vehicle dynamics Docking vehicle orbit control Power profile Wheel speeds Thrust Relative nav

15. HPM - Guidance, Navigation & Control (Technology Requirements) TechnologyDescription/ Metrics TRLCurrent Technology Research ActivitiesOther Applications Where Who Funding Increase? MANS Microcosm Autonomous Navigation System Requires development of software, hardware definitions/interfaces, testing for deep space platforms. 5Micro- cosm Inc. Gwynne Gurevich Phone: (310) 726- 4100 TBD Can use NASA SBIR SmallAttitude and Position info for any satellite in space, near Earth or deep space AFF Autonomous Formation Flying Based on GPS technology and can work in deep space with or without GPS satellites. Needs on- board implementation & testing. 1cm relative position 0.1mm/s relative velocity 1arc-minute attitude Average Power=1W Less than 2kg 3 JPL Kenneth Lau Initial funding from NASA complete SmallFor any in-space rendezvous and docking between spacecraft & formation flying. 100m position info 0.03deg attitude info 11kg & 28W based on sensor suite used

16. C&DH/C&T Systems & Technologies Functional Description: Communications, command, telemetry, and recorder systems Key Performance Requirements: Low data rate: 2000 bps or less telemetry,1000 bps or less command 1 day data storage capability 3 dB link margin from E-S L 2 Low gain patch antennas Medium gain horn antennas Redundancy in all three systems M - Moderate technology mass = 22 Kg E - Extreme technology mass = 8 Kg Technology (C&T)MassPower Current capability31 Kg65 W Shrink power amp/transponder2045 Shrink power amp/transponder1035 Technology (C&DH)MassPower Current capability11 Kg39 W Integrated system 725 System on a Chip 315 Key Technologies

17. C&DH/C&T Attached vehicles (CTM, SEP) S-Band Communications System Computers Recorders Other systems Power, Prop, etc. Attached vehicles (CTV, Gateway, OTV, ISS) Power Amp Transfer SW Power Amp C&DH Diplexer RF SW S-Band Transponder C&DH SW Transfer C&DH S-Band Communications (C&T)

18. HPM C&DH/C&T Technology Summary

19. Propellant Management System & Technologies Functional Description: Efficient systems for transfer and storage of cryogenic fluids for long periods of time Key Performance Requirements: LH2 Tank Volume = 65 m**3 LO2 Tank Volume = 24.2 m**3 LXe Tank Volume = 3 m**3 Loss kg/month = near zero Re-usability: 4 fill and drain cycles per year for 10 years with no refurbishment Design/Technology Description: Take advantage of the tremendous advances in cryo-cooler technology and combine active (cryo coolers) and passive (multi-layer insulation-MLI) thermal control technologies to remove heat entering a cryogenic propellant tank and control tank pressure. Develop new technology to routinely and autonomously transfer cryogenic propellants for in-space operations. Cryocooler Cold Finger MLI Blankets Vapor Cryogen Space Heat Exchanger Radiator Solar Array Possible ZBO In-Space Configuration

20. Propellant Management System LOX LH 2 H 2 Vent Pressure Building Coil O 2 Vent Xe Xe Vent Key Valve Relief Valve Burst Disk Can we put the Cryo- coolers on this schematic?

21. HPM Propellant Management Technology Summary

22. POWER GENERATIONSpecifc Power 1 Efficiency MBG 2 Crystalline PV 200 W/kg30% Thin Film PV200 W/kg10% MBG Crystalline PV250 W/kg40% Thin Film PV270 W/kg15% Thin Film PV600 W/kg20% Advanced Array Designs>400 W/kg>40% Quantum Dots 3 >500 W/kg60% Functional Description: The Electrical Power System consists of power generation for HPM (house- keeping), CTM, CTV and the SEP Stage, energy storage for HPM, CTM, and CTV power during shadow, and power processing. Key Performance Requirements: Minimal system mass and volume Reliability; cycling capability Radiation degradation resistant for system lifetime of 10 years Capable of power generation with arrays stowed (at reduced level) Redeployable ENERGY STORAGESpecificCycleDepth of EnergyLifetime/Discharge Efficiency Li-based batteries 4 100 Wh/kg30 kCyc.60% Century Flywheel 5 45 Wh/kg75 kCyc.89% Active Dedicated RFC 6 400 Wh/kg55% Eff. Li-based batteries 4 200 Wh/kg30 kCyc.70% Advanced Flywheel 5 100 Wh/kg75 kCyc.89% Passive Unitized RFC 6 1000 Wh/kg65% Eff. Full polymer batteries 4 300 Wh/kg20 yrs (GEO)70% Future Flywheel 5 150 Wh/kg>95 kCyc.90% Passive Unitized RFC 6 >1000 Wh/kg80% Eff. POWER PROCESSINGSpecificEfficiencyTemperature Energy Converter w/Active Control0.5 kW/kg90%125 °C 300V Power Distribution0.3 kW/kg Modular, High-Temp.1.5 kW/kg95%225 °C Converters 600V Power Distribution0.7 kW/kg High-Temp. PMAD System3.0 kW/kg95%350°C 1200V Power Distribution1.4 kW/kg Notes: 1 - Array level specific power 2 - Multiple band gap cells (I.e. 2, 3, and 4 junctions) 3 - High Risk/high Potential technology 4 - Does not include power electronics mass 5 - Includes power electronics mass 6 - Regenerative Fuel Cell: Specific Energy is a function of discharge time Power System

23. Hybrid Propellant Module Power System Performance Guidelines Power Generation: 3.1 kW required at 100% duty cycle During LEO to Earth-Moon L1 transfer and return Energy Storage: Provide required power during shadow/chemical rocket use Cross-use capability Operating Life: 10 year system lifetime (~ 5 round trips) Preliminary Configuration PV Arrays: Rigid Planar structures Stowed on exterior of HPM Arrays retracted during chemical rocket firing Energy Storage: Flywheel systems 5.1 kWh capacity required Sharing functions with attitude control system Flywheels Solar Array Charge/ Discharge System Thermal control Solar Array Power Processing Power Regulation & Control Power Distribution To Spacecraft Bus Baseline EPS Schematic

24. Hybrid Propellant Module Power System RESULTS Technologies selected: Advanced crystalline multi-band gap photovoltaics 47% eff. @ AM0, 135 W/kg @ panel Flywheel energy storage 5.1 kWh capacity, 3.3 kW delivered, 89% DOD Advanced power processing 95% eff., 670 W/kg

25. Hybrid Propellant Module Power System Technology Requirements my preliminary guesses - will fill out with better info

26. Mass Properties – HPM Block 2 SubsystemCalculated Mass (kg) Navigation/Attitude Control 11.84 Command/Control/Comm 41.50 Thermal 93.35 Power 264.00 Propellant Management 1,089.44 Structures 1,240.00 Shielding 1,582.00 Calculated Dry Mass 4,322.13 Dry Mass Margin -218.13 Dry Mass Target Mass 4,104.00