MARTIAN HABITAT DESIGN

MARTIAN HABITAT DESIGN MARS OR BUST, INC. UNIVERSITY OF COLORADO, BOULDER AEROSPACE ENGINEERING SCIENCES ASEN 4158/5158 MOB DECEMBER 17, 2003

TABLE OF CONTENTS 1 MISSION SUMMARY... 8 1.1 CONTEXT OF THIS DESIGN EXERCISE... 8 1.2 SUMMARY OF MISSION CHARACTERISTICS... 9 1.3 KEY ASSUMPTIONS... 9 1.4 TOP LEVEL REQUIREMENTS... 9 2 SYSTEMS ENGINEERING AND INTEGRATION... 10 2.1 SUBSYSTEM OVERVIEW... 10 2.2 KEY ASSUMPTIONS... 11 2.3 DESIGN PHILOSOPHY... 11 2.4 DESIGN OVERVIEW... 12 3 MARS ENVIRONMENT AND IN-SITU RESOURCE UTILIZATION... 14 3.1 MARS ENVIRONMENT OVERVIEW... 14 3.2 MARS ENVIRONMENT PARAMETERS... 14 3.3 FUTURE CONSIDERATIONS... 20 4 IN-SITU RESOURCE UTILIZATION... 20 4.1 LEVEL 2 REQUIREMENTS... 20 4.2 INTERFACE DESIGN... 22 4.3 OPERATIONS... 24 4.4 SUMMARY OF ISPP PLANT DESIGNS AND PROCESSES... 25 4.5 BENEFITS OF ISRU FOR FUTURE MISSIONS... 29 4.6 ADDITIONAL MARTIAN RESOURCES WATER AND SOIL... 29 4.7 VERIFICATION OF REQUIREMENTS... 30 4.8 FUTURE CONSIDERATIONS... 31 5 STRUCTURES SUBSYSTEM... 31 5.1 OVERVIEW... 31 5.2 LEVEL 2 REQUIREMENTS... 31 5.3 INPUT/OUTPUT DIAGRAM... 32 5.4 DESIGN AND ASSUMPTIONS... 33 5.5 VERIFICATION OF REQUIREMENTS... 45 6 ELECTRICAL POWER DISTRIBUTION AND ALLOCATION SUBSYSTEM... 48 6.1 OVERVIEW... 48 6.2 DESIGN AND ASSUMPTIONS... 52 6.3 VERIFICATION OF REQUIREMENTS... 55 6.4 FUTURE CONSIDERATIONS:... 57 7 ENVIRONMENTAL CONTROL AND LIFE SUPPORT SUBSYSTEM... 57 7.1 OVERVIEW... 57 7.2 REQUIREMENTS... 59 7.3 ATMOSPHERE SUBSYSTEM... 60 7.4 WATER SUBSYSTEM... 68 7.5 WASTE SUBSYSTEM... 78 7.6 FOOD SUBSYSTEM... 82 7.7 INTEGRATED SYSTEM... 86 7.8 CONCLUSION... 96 8 THERMAL CONTROL SUBSYSTEM... 97 8.1 REQUIREMENTS... 97 8.2 OVERVIEW OF DESIGN PROCESS... 98 Page 2 of 264

8.3 THERMAL SUBSYSTEM DESIGN... 99 8.4 VERIFICATION OF REQUIREMENTS... 105 8.5 FAILURE MODES EFFECTS ANALYSIS... 107 8.6 FUTURE CONSIDERATIONS... 108 9 CREW ACCOMMODATIONS... 110 9.1 CREW ACCOMMODATIONS OVERVIEW... 110 9.2 CREW ACCOMMODATIONS DESIGN AND ASSUMPTIONS... 113 9.3 CREW ACCOMMODATIONS VERIFICATION OF REQUIREMENTS... 122 9.4 CREW ACCOMMODATIONS FAILURE MODES AND EFFECTS ANALYSIS... 123 9.5 CREW ACCOMMODATIONS CONCLUSIONS... 126 10 COMMAND, CONTROL, AND COMMUNICATION SUBSYSTEM... 127 10.1 OVERVIEW... 127 10.2 DESIGN AND ASSUMPTIONS... 127 10.3 VERIFICATION OF REQUIREMENTS... 145 11 ROBOTICS AND AUTOMATION SYSTEMS AND INTERFACES... 147 11.1 OVERVIEW... 147 11.2 DESIGN AND ASSUMPTIONS... 148 11.3 VERIFICATION OF REQUIREMENTS... 152 12 EXTRAVEHICULAR ACTIVITY INTERFACES SUBSYSTEM... 154 12.1 OVERVIEW... 154 12.2 DESIGN AND ASSUMPTIONS... 159 12.3 REQUIREMENTS VERIFICATION... 170 13 MISSION OPERATIONS... 173 13.1 MISSION OPERATIONS OVERVIEW... 173 13.2 MISSION OPERATIONS DESIGN AND ASSUMPTIONS... 181 13.3 MISSION OPERATIONS VERIFICATION OF REQUIREMENTS... 194 13.4 MISSION OPERATIONS FAILURE MODES AND EFFECTS ANALYSIS... 196 13.5 MISSION OPERATIONS CONCLUSIONS... 197 14 MANAGEMENT PLAN... 198 14.1 OVERVIEW... 198 14.2 SCHEDULE... 199 15 CONCLUSIONS... 202 15.1 DESIGN SUMMARY... 202 15.2 KEY DESIGN DRIVERS... 203 15.3 KEY CHALLENGES... 204 16 APPENDIX A: REVIEW OF MARS EXPLORATION PAST, PRESENT, AND FUTURE... 205 16.1 MARS 1960 A/B, USSR (TIM LLOYD)... 205 16.2 MARS 1, USSR (TIM LLOYD)... 205 16.3 SPUTNIK 24, USSR (KEAGAN ROWLEY)... 205 16.4 ZOND 2/3, USSR (TIM LLOYD)... 205 16.5 MARS 1969 A/B, USSR (JEN UCHIDA)... 206 16.6 COSMOS 419, USSR (KEAGAN ROWLEY)... 207 16.7 MARS 2/3, USSR (MERIDEE SILBAUGH)... 207 16.8 MARS 4, 5, 6, 7, USSR (MERIDEE SILBAUGH)... 208 16.9 THE VIKING PROJECT, USA (HEATHER CHLUDA)... 210 16.10 PHOBOS 1/2, USSR (TIM LLOYD)... 212 16.11 MARS OBSERVER, USA (ERIC SCHLEICHER)... 213 Page 3 of 264

16.12 MARS 96, RUSSIA (KEAGAN ROWLEY)... 215 16.13 MARS GLOBAL SURVEYOR, USA (ERIC SCHLEICHER)... 217 16.14 MARS CLIMATE ORBITER, USA (NANCY KUNGSAKAWIN)... 218 16.15 MARS POLAR LANDER, USA (TERESA ELLIS)... 220 16.16 2001 MARS ODYSSEY, USA (NANCY KUNGSAKAWIN)... 221 16.17 NOZOMI, JAPAN (JEN UCHIDA)... 222 16.18 MARS EXPRESS, ESA (TERESA ELLIS)... 223 16.19 MARS EXPLORATION ROVERS, USA (DAX MATTHEWS)... 225 16.20 MARS RECONNAISSANCE ORBITER, USA (MERIDEE SILBAUGH)... 227 16.21 REVIEW OF MARS DIRECT: A PROPOSAL BY ROBERT ZUBRIN (TYMAN STEPHENS)... 228 16.22 HUMAN EXPLORATION OF MARS: THE REFERENCE MISSION OF THE NASA MARS EXPLORATION STUDY TEAM (KEITH MORRIS)... 232 16.23 MARS EXCURSION MODULE, ESA AURORA STUDENT DESIGN PROJECT (JUNIPER JAIRALA)... 234 16.24 NASA AIM (CHRISTIE SAUERS)... 239 16.25 THE MARS SOCIETY (CHRISTIE SAUERS)... 240 16.26 FLASHLINE MARS ARCTIC RESEARCH STATION (JEFF FEHRING)... 242 17 APPENDIX B: ACRONYMS... 246 18 APPENDIX C: MARS ENVIRONMENT INFORMATION SHEET... 247 18.1 GRAVITY... 247 18.2 ORBITAL CHARACTERISTICS... 247 18.3 ATMOSPHERE... 247 18.4 TEMPERATURE... 250 18.5 SOLAR FLUX... 252 18.6 RADIATION... 252 18.7 WIND... 253 18.8 SOIL PROPERTIES... 253 18.9 MARS FACT SHEET... 254 19 APPENDIX D: REFERENCES... 257 20 APPENDIX D: ACKNOWLEDGEMENTS... 264 TABLE OF FIGURES Figure 2.1: Subsystem Archetecture... 12 Figure 2.2: Input/Output Diagram... 13 Figure 2.3: General Layout of Habitat... 14 Figure 3.1: Atmospheric Pressure at Surface of Mars... 15 Figure 3.2: Atmospheric Pressure at the Surface of Mars, continued... 16 Figure 3.3: Diurnal Temperature Variation... 18 Figure 3.4: Diurnal Temperature Variation over Sol 06... 18 Figure 4.1: Input / Output Diagram... 22 Figure 4.2: ISRU Functional Subsystem Schematic... 23 Figure 4.3: Zirconia Electrolysis... 25 Figure 4.4: Sabatier Electrolysis... 26 Figure 4.5: Reverse Water Gas Shift to produce Oxygen... 27 Figure 4.6: Reverse Water-gas Shift and an Ethylene Reactor... 28 Figure 5.1: Input/Output Diagram for Structures subsystem.... 32 Figure 5.2: Upper floor plan.... 33 Figure 5.3: Bottom floor plan.... 34 Figure 5.4: Habitat view from the bottom showing the position of the leg supports.... 39 Page 4 of 264

Figure 5.5: Simple force diagram of the habitat.... 39 Figure 6.1: Input/Output Diagram... 52 Figure 6.2: General Functional Diagram... 53 Figure 6.3: Life/Mission Critical... 53 Figure 6.4: ECLSS... 54 Figure 6.5: C 3... 54 Figure 6.6: Failure Tree... 57 Figure 7.1: Subsystem Interactions... 59 Figure 7.2: Baseline non-regenerable physical/chemical air ECLSS schematic... 63 Figure 7.3: Physical/Chemical Air Life Support System Schematic Option A... 66 Figure 7.4: Physical/Chemical Air Life Support System Schematic Option B... 67 Figure 7.5: Open Loop Diagram w/flow Rates in kg/day for 6 crewmembers... 70 Figure 7.6: Closed Loop Water Management Flow Diagram... 73 Figure 7.7: Electronic Nose Equipment... 75 Figure 7.8: Ion Specific Electrode... 75 Figure 7.9: Total Organic Carbon - Conductivity Diagram... 76 Figure 7.10: Actual Total Organic Carbon Device... 76 Figure 7.11: Sample of Conductivity Device... 76 Figure 7.12: Sample Test Kits... 76 Figure 7.13: Order of Monitoring Devices... 77 Figure 7.14: Schematic of the Waste Management Subsystem... 80 Figure 7.15: Food System Schematic... 85 Figure 7.16: ECLSS Integrated Design... 87 Figure 7.17: Interfaces between ECLSS and other subsystems... 89 Figure 8.1: Input/Output Diagram... 99 Figure 8.2: Thermal System Schematic... 100 Figure 8.3: A radiator used aboard the ISS... 104 Figure 8.4: FMEA Breakdown... 108 Figure 9.1: Crew Accommodations Active Equipment Interfaces... 120 Figure 10.1: C 3 Subsystem Input Output Diagram... 129 Figure 10.2: Command and Control Architecture... 131 Figure 11.1: Input/output diagram for Robotics and Automation... 148 Figure 11.2: Mars Exploration Rover... 149 Figure 11.3: Conceptual Local Unpressurized Rover... 150 Figure 11.4: Conceptual Mechanical Arm for the LPR... 150 Figure 13.1: Overview MOB Mission Timeline for Mars Stay... 190 Figure 13.2: Representative crew timeline for a typical month on Mars during the MOB Mission... 191 Figure 13.3: Representative crew timeline for the majority of days on Mars during MOB mission... 192 Figure 13.4: Representative crew timeline for days when an EVA is performed... 192 Figure 13.5: Representative crew timelines for proficiency training days that occur monthly... 193 Figure 14.1: Mars or Bust Schedule... 200 Figure 16.1: Mars 1969 A/B Orbital Details... 207 Figure 16.2: Aerobraking Map of the Orbiter... 219 Page 5 of 264

Figure 16.3: Representative Art on Orbiter's Aerobraking Period... 219 Figure 16.4: Nozomi Mission Sequence... 223 Figure 16.5: Conceptual Drawing of an Operational Rover... 225 Figure 16.6: Mars Direct Mission Schedule... 229 Figure 16.7: The MTV, the Earth-Mars transit vehicle outlined by Mark Ford (1996); the MEM is on the far right.... 235 Figure 16.8: Habitat presentation... 238 Figure 16.9: Artists concept of the operational Advance Integration Matrix (AIM) facility at NASA, Johnson Space Center... 240 Figure 16.10:An aerial photo of the Mars Society Flashline Mars Arctic Research Station (FMARS), located in the Canadian Arctic on Devon Island.... 241 Figure 16.11: The Mars Desert Research Station (MDRS) located in Hanksville, UT.. 242 TABLE OF TABLES Table 1.1: Top-Level Habitat Requirements from DRM... 10 Table 3.1: Mars Environment Parameters... 15 Table 3.2: Atmospheric Composition... 16 Table 3.3: Landing sites of Viking 1 and 2 landers and Pathfinder landers... 17 Table 3.4: Mars Environment Seasonal Parameters... 19 Table 4.1: Level 2 Requirements... 21 Table 4.2: Mass, Power, Volume Breakdown... 23 Table 4.3: Properties and flow rates of consumables... 24 Table 4.4: ISPP Trade Study... 29 Table 4.5: Verification of Requirements... 30 Table 5.1: Level 2 Requirements... 31 Table 5.2: Volume allocation and designed volume of subsystems.... 35 Table 5.3: Key physical properties of aluminum... 37 Table 5.4: Launch and landing load factors.... 38 Table 5.5: Failure Mode Effects Analysis... 44 Table 5.6: Mass and Volume Estimates of Structures Components... 45 Table 5.7: Requirements Verification... 46 Table 6.1: Level 2 Requirements... 48 Table 6.2: Power Profile... 49 Table 6.3:Electrical Cabling Mass and Thermal Breakdown... 49 Table 6.4: Power System Masses and Volumes... 50 Table 6.5: Mass/Volume Breakdown... 51 Table 6.6: Requirements Verification... 56 Table 7.1: Baseline Non-regenerable Physical/Chemical Air Life Support System... 62 Table 7.2: Air Management Life Support Technology Rankings... 64 Table 7.3: Physical/Chemical Air Life Support System for Mars Mission Option A... 65 Table 7.4: Physical/Chemical Air Life Support System for Mars Mission Option B... 65 Table 7.5: Heat, Power, and Volume for ECLSS atmosphere technologies... 68 Table 7.6: Water Quality Requirement: Maximum Contaminant Levels... 69 Table 7.7: Water Management Parameters... 70 Table 7.8: Hygiene & Potable Water Treatment Candidate Technologies... 71 Table 7.9: Urine Treatment Candidate Technologies... 72 Page 6 of 264

Table 7.10: List of Technologies & Associated TRLs... 74 Table 7.11: Water Sample Requirement for Off-Line Monitoring (Initial On-Orbit Operations)... 77 Table 7.12: Water Sample Requirement for Off-Line Monitoring (Mature Operations). 77 Table 7.13: Heat, Power, and Volume for ECLSS Water Technologies... 78 Table 7.14: Waste Product Breakdown for a 6-Person Crew... 79 Table 7.15: Heat, Power, and Volume for ECLSS Waste Technologies... 81 Table 7.16: Food Technology Specifications... 84 Table 7.17: Heat, Power, and Volume for ECLSS Food Technologies... 86 Table 7.18: ECLSS Total Mass, Power, and Volume Estimates... 90 Table 7.19: Total Mass and Volume Values for Consumables... 92 Table 7.20: Water Requirements... 92 Table 7.21: Verification of Requirements... 93 Table 8.1: Level 2 Requirements... 97 Table 8.2: Heat Loads from Subsystems... 101 Table 8.3: Thermal System Mass, Power, and Volume... 103 Table 8.4: Requirement Verification Summary... 105 Table 9.1: Crew Accommodations Top Level Requirements... 111 Table 9.2: Crew Accommodations Level 2 Requirements... 111 Table 9.3: Crew Accommodations Subsystem Equipment List... 114 Table 9.4: Non-Active Crew Accommodations Equipment... 118 Table 9.5: Clothing Trade Study... 121 Table 9.6: Crew Accommodations Requirements Verification... 122 Table 10.1: C 3 Level 2 Requirements... 128 Table 10.2: Command and Control Power... 137 Table 10.3: Command and Control Mass and Volume... 138 Table 10.4: Command and Control Failure Modes Effects Analysis... 139 Table 10.5: ECLSS and Power Data for Transmission to Earth... 141 Table 10.6: Thermal, Structures, ISRU and Mission Ops Data for Transmission to Earth... 142 Table 10.7: Earth-Mars Link Budget... 143 Table 10.8: Mars Habitat Link Summary... 143 Table 10.9: C 3 Requirements Verification... 146 Table 11.1: Automation & Robotics Level 2 Requirements... 147 Table 13.1: Mission Operations Requirements... 174 Table 13.2: Subsystem Operations List... 181 Table 13.3: Mission Operations Requirement Verification... 194 Table 14.1: MOB Organizational Chart... 199 Table 15.1: Mass Breakdown... 202 Table 15.2: Aurora Mass Breakdown... 203 Table 16.1: Consumable Requirements for Mars Direct Mission with Crew of Four... 230 Table 16.2: Mass Allocations for Mars Direct Mission Plan... 231 Table 16.3: Internal heat sources... 237 Table 16.4:Summary of power demands... 237 Table 16.5:Summary of final HAB mass budget... 238 Page 7 of 264

1 Mission Summary 1.1 Context of this design exercise 1.1.1 Introduction and academic context This report describes the process and findings of a semester-long exercise designing a habitat for the surface of Mars. The mission described in this report is a subset of the NASA Design Reference Mission for Human Exploration of Mars. This design exercise was conducted by the students of the Fall 2003 course on Space Habitat Design at the University of Colorado at Boulder, under the instruction of Dr. David Klaus. 1.1.2 Overview of the Design Reference Mission For the purpose of this design exercise, we have used the basic mission outlined in versions 1.0 [Hoffman and Kaplan, 1997] and 3.0 [Drake, 1998] of the NASA Mars DRM. In version 1.0, a series of four spacecraft are launched to Mars over two separate launch opportunities to support a 6-person crew. A fully fueled Earth Return Vehicle (ERV) is first sent to Mars orbit. A Mars Ascent Vehicle (MAV) is then sent to land on Mars, carrying power production systems and an In-Situ Resource Utilization unit (ISRU), and begin producing propellant for the ascent from the Mars surface. A surface habitat/laboratory lands next, carrying non-perishable consumables and another power plant. After these three spacecraft are checked out and verified to be fully operational, the next launch opportunity sends the crew, via the Crew Transfer Vehicle (CTV), and two more cargo vessels. The crew travel on a fast 180 day transit to Mars, carrying enough consumables for a contingency stay in their transit habitat, land next to the already checked out habitat, and begin their 600-day surface mission. The two cargo vessels are identical to the ERV and MAV from the first launch opportunity, and are to be used either for the next exploration crew, or for redundancy for the first crew. For this version of the DRM, the Mars base consists of one fully fueled MAV, one habitat/laboratory, and a transit habitat/laboratory, with a fully fueled ERV in low Mars orbit (LMO). Version 3.0 of the DRM incorporates many cost-cutting and simplifying changes to version 1.0. Specifically, it eliminates the need for a separate MAV. The first launch opportunity sends two spacecraft to Mars. One is a fully fueled ERV, and the other is a cargo lander that contains an ISPP, power production systems, an inflatable TransHabstyle habitat, and ascent vehicle. In the second launch opportunity, the crew is launched in a transit habitat, carrying enough consumables for a contingency stay, and lands next to the cargo lander. The Mars base for version 3.0 consists of the cargo lander with fully fueled MAV and inflatable habitat, the transit habitat, and a fully fueled ERV in LMO. Page 8 of 264

1.2 Summary of mission characteristics MARS OR BUST, LLC The goal of this class, established by Dr. Klaus, was to design a habitat for the surface of Mars. With this goal in mind, the overall missions outlined in DRM versions 1.0 and 3.0 have been combined with a few modifications. The habitat described in this design exercise is meant to fit within a number of different mission scenarios. For the purposes of this exercise, some assumptions have been made about the mission that will use this habitat. The mission will be similar to DRM versions 1.0 and 3.0 in that the crew will travel to Mars in a vehicle separate from the habitat in which they will live on the surface of Mars. The habitat will also be separate from the laboratory in which the astronauts will perform various experiments. It was decided not to design any aspect of the Earth-Mars-Earth transit or the laboratory, in order to better focus on the design of the habitat. Similar to the DRM version 3.0, the first launch opportunity will send the habitat, encased in a transfer vehicle, as well as a nuclear power plant, several rovers, and an In- Situ Resource Utilization Plant (ISRU). Upon arrival at Mars, the habitat will aerobrake using the transfer vehicle, then be jettisoned from the transfer vehicle, parachute through the Martian atmosphere, and land using retrorockets at a designated landing site. The transfer vehicle, aerobraking, parachutes, and landing were not included as part of this design project, in order to better focus on the design of the habitat. The nuclear power plant, rovers, and ISRU will arrive in a similar manner, and land near the habitat. The rovers will be sent instructions from Earth Mission Control to move the habitat, power plant, and ISRU within 50 meters of one another, and connect and configure these elements of the Mars base. Mission Control will then command the elements of the Mars base to power on and perform self-tests in preparation for the arrival of the astronaut crew. 1.3 Key Assumptions Only the surface habitat was designed. The equipment outside of the habitat was not designed, but interfaces to them were. For example, the EVA suits were not designed, but some basic requirements for the suits were chosen, along with the design of the storage, maintenance, and supplies. The habitat is designed to fully function only on the surface of Mars, as it will not be manned during transit. This design therefore focuses only on the surface operations of the habitat, although aspects of the launch, transit, and Mars landing are considered. 1.4 Top Level Requirements Several top-level requirements were directly taken from the DRM. These requirements are given in Table. Page 9 of 264

Table 1.1: Top-Level Habitat Requirements from DRM # Requirement Description Source 1.1 Habitat must support crew of 6. DRM 1.2 Habitat must support crew for 600 days without re-supply. DRM 1.3 Habitat must be deployed 2 years before first crew arrives. DRM 1.4 Habitat shall be in a standby mode for 10 months between crews. DRM 1.5 All systems in Habitat must have a minimum operational lifetime of 15 years. DRM 1.6 All systems in Habitat must have low failure rates. DRM 1.7 Crew health and safety must be maintained. DRM 1.8 In-Situ Resource Utilization System must be integrated with the Habitat where applicable, but cannot be initially relied upon. DRM 1.9 Dependence on support from Earth must be minimized. DRM 1.10 Habitat surface infrastructure must be setup and checked out before crew leaves Earth. DRM 1.11 Total Habitat mass (including all payload) must not exceed 34 metric tonnes. DRM 1.12 All mission critical systems must have 2-level redundancy. DRM 1.13 All life critical systems must have 3-level redundancy. DRM 1.14 Habitat will be launched in an 80 metric ton launch vehicle. DRM 1.15 Habitat must land, deploy, operate, and maintain all systems. DRM 1.16 Where possible, habitat systems must be modular. DRM 1.17 Where possible, habitat systems must be easily repairable. DRM 1.18 Electronic and mechanical equipment must be highly autonomous, self-maintained or crew maintained, and, where possible, self-repairing. DRM 1.19 Habitat shall have auto fault detection and correction for all life-critical and mission discretionary elements. DRM 1.20 Systems must be easy to learn to operate, similar, and use common software and hardware. DRM 1.21 Crew must be able to perform real time science activity planning. DRM 1.22 All systems must survive and/or remain functional during launch and transit to Mars. DRM 2 Systems Engineering and Integration 2.1 Subsystem Overview The responsibilities of the Systems Engineering team are to ensure cohesiveness of the habitat design and fulfillment of all mission requirements. Specific tasks include identifying and deriving requirements from the DRM, delegating those requirements to the subsystem teams, reviewing and reconciling subsystem designs and coordinating subsystem interfaces. This team also worked closely with the Mission Operations to ensure consideration of human factors from the beginning of design. They worked closely with project management to oversee, organize and direct the subsystem teams, develop report and presentation templates, establish comprehensive project schedules, conduct meetings, and provide expertise to individual subsystems. Page 10 of 264

2.2 Key Assumptions It was assumed that the mission infrastructure delineated by the DRM would in fact be present upon arrival of the habitat. The Martian base infrastructure includes a nuclear reactor power source capable of providing 160 kwe of power, with 25 kwe allocated to the habitat, and the cabling necessary to transport the power to the habitat, an ISRU plant, 2 large pressurized rovers capable of moving the habitat and one small scientific rover. Other assumed mission infrastructure includes a launch vehicle capable of transporting 80 tonnes from the surface of Earth to Mars and a Martian landing site conducive to landing and all surface operations. The habitat was designed to withstand transportation from Earth to Mars, but a thorough consideration of mission modes other than surface operations was outside the scope of this project. Thus, transit, launch, entry, descent, and landing modes were considered but were not included as key drivers for this design. Other assumptions include: The crew would have the capability to perform EVAS There could be no dependence on the CTV There will be communication satellite(s) in orbit around Mars There will be up to a 40 minute communication delay with Earth (during open communication windows) Each crew member s physical profile is between the 5 th percentile Japanese female and the 95 th percentile American male human profile Environmental factors are within those documented (including wind speeds, dust constituents, temperature, micrometeors, etc) 2.3 Design Philosophy As with all space missions, it was important to minimize mass, power and cost for this project. However, mass was a bigger driver than power for this design because the launch capability was well defined, while the power source has yet to be designed. The goal of this design was to focus on overall system engineering approach, including human factors and infrastructure interfaces. Hardware choices were limited to technologies with high TRL (7 or higher), and subsystems were designed to handle worst-case scenarios (hot-hot, all power on at once, etc) to establish a baseline design. The design met the full redundancy required by the DRM without analysis of reliability. Planetary environmental protection and mission justification were not considered as they are programmatic rather than engineering decisions. The design was based heavily on the key DRM requirements, as reevaluation of these requirements was not within the scope of this project. 2.3.1 Subsystem Architecture The overall design was split into 12 subsystems at the beginning of the project. These subsystems are listed in Figure 2.1. Page 11 of 264

Figure 2.1: Subsystem Archetecture The full names of the subsystems are listed below; the responsibilities of each subsystem are discussed in the corresponding section of this document. MOB Subsystems Program Manager Systems Engineering and Integration Mission Operations (MO) Structures Command, Control, and Communication (C 3 ) Electrical Power Management and Allocation (Power) Environmental Control and Life Support (ECLSS) Crew Accommodations (CA) Robotics and Automation Systems and Interfaces (Robotics) ExtraVehicular Activity Interfaces (EVAS) Thermal Control (Thermal) In-Situ Resource Utilization (ISRU) 2.4 Design Overview The MOB habitat has a pressurized volume of 616 m 3, an unused volume of 211 m 3, an overall mass of ~ 68000 kg, and a maximum power consumption of 43 kwe. The overall structural layout is shown in Figure 2.3, and the input/output diagram for the entire habitat system is shown in Figure 2.2. Each subsystem will discuss their individual inputs and outputs in their corresponding section. Page 12 of 264