human studies

Slide1: 

John Connolly Kent Joosten January 6, 2005 Session 6: Human Mars Exploration Mission Architectures and Technologies

Topics: 

Topics Human Mars Mission Architectures Trade Tree/Past Studies Long-stay vs. Short-stay Missions Short-stay Mission Example Long-stay Mission Example Key Findings Mission Mode In-Space Transportation Human Health and Performance Advanced Life Support Surface Systems Space Power Cross-cutting Technologies Enabling Capabilities and Technologies

Major Architectural Considerations: 

Major Architectural Considerations Mission class Short-Stay (opposition class) Long-Stay (conjunction class) Split mission vs. all-up Pre-deploy (split mission) All-up (single integrated vehicle) Launch vehicle capability Existing (maximum 20mt) 40-60mt 80 mt + Mars staging location Low Mars Orbit Libration Points None (direct or cycler) Power and propulsion choices Conventional Nuclear Crew size Use of resources Total mission duration, surface duration, total energy, crew risk exposure (radiation, gravity), amount of science performed Pre-deployment of assets, departure staging location, multiple departure/arrival windows, multiple vs one large spacecraft, abort options Number of launches required, extent and duration of on-orbit operations Division of functions across flight elements, number of elements, energy split, departure options, abort options, technology options Total mission mass, technology development risk, trip time, surface mission duration Total mission mass, redundancy, amount of science performed Propellant mass, consumables mass, total mission mass, extensibility, redundancy, risk Decision: Impacts:

Example Mars Architecture Trade Space: 

In-Space Propulsion Mars Capture Aerocapture? Mission Type Conjunction (long stay) vs. Opposition (short stay) Pre-Deploy Split vs. All-up Local Resource Utilization? Increasing “Performance” Decreasing vehicle wet mass, decreasing trip times, increasing payload, more challenging mission classes Chemical Nuclear Thermal Solar Electric / Chemical Solar Electric Nuclear Electric w/o AC w/ AC Conj (1952 Von Braun) Opp X Excessive Mass Conj Opp Split All Up All Up w/o ISRU w/ ISRU w/o AC w/ AC Conj Conj Opp w/o ISRU w/ ISRU Split All Up Opp Œ  Ž w/o AC w/ AC Conj Conj Opp Split All Up All Up w/o ISRU w/ ISRU Split All Up Opp   ‘ ’ ” “ • ‚ w/o AC w/ AC Conj Opp X Config.  w/o AC w/ AC Conj Split All Up Opp X Config. ‚ X Config.  X Excessive Size ? ? Questionable Feasibility Example Mars Architecture Trade Space Œ 1988 “Mars Expedition”  1989 “Mars Evolution” Ž 1990 “90-Day Study”  1991 “Synthesis Group”  1995 “DRM 1” ‘ 1997 “DRM 3” ’ 1998 “DRM 4” “ 1999 “Dual Landers” ” 1989 Zubrin, et.al* • 1994-99 Borowski, et.al  2000 SERT (SSP) ‚ 2002 NEP Art. Gravity “High Thrust” “Low Thrust” Hybrid *Assumptions not necessarily consistent

Human Mars Mission Architectures: 

Human Mars Mission Architectures Mission Mode: Long-stay vs. Short-stay Operational Issues Microgravity Reconditioning Global Dust Storms Systems failure/repairs Reaction to unexpected findings Surface system reliability Flight system reliability Surface system investment vs. time/revisits

Example Short-Stay Missions: 

Example Short-Stay Missions Typically referred to as “opposition class” missions Characterized by: High-propulsive requirements Large variation in energy requirements across mission opportunities Venus swing-by or deep-space Maneuvers Close perihelion passage Short outbound and long inbound transits separated by short surface stay Short to long total mission durations Majority (90+%) of crew time spent in deep-space environment Arrive Mars 12/16/31 Depart Mars 1/25/32 Depart Earth 2/6/31 Arrive Earth 11/28/32 Example Short-Stay Mission

Example Long-Stay Missions: 

Example Long-Stay Missions Typically referred to as “conjunction class” missions Characterized by: Lower-propulsive requirements Small variation in energy requirements across mission opportunities All mission > 1 Au Short transits separated by long-surface mission Long total mission durations Majority (50+%) of crew time spent on Mars Depart Earth 5/11/18 Depart Mars 6/14/20 Arrive Earth 12/11/20 Arrive Mars 11/7/18 Example Long-Stay Mission

Mission Energy Comparison: 

Mission Energy Comparison

Short-Stay Mission ExampleRef: 2002 SA NEP Artificial Gravity Mission: 

Characteristics Initial missions limited to 18-24 month round trip (18 month goal) Three months stay in Mars system “Split mission” – no “Mars-specific” cargo sent out with crew Assembly Orbit: Low Earth orbit Departure/return point: High Earth orbit Destination: High Mars orbit Piloted vehicle stack less than 200 tons initial mass Rationale Stresses interplanetary “steering” requirements (possible Artificial-G concern) Stresses inner solar system operating regime (0.5-1.5 AU) Stresses propulsion performance Out of 18-24 month round trip, three months Mars stay with no gravity readaptation time required may represent good mission productivity “Split mission” maintains destination-independence of crew transfer vehicle Earth’s Neighborhood transportation infrastructure (XTV) utilized for crew delivery/return Short-Stay Mission Example Ref: 2002 SA NEP Artificial Gravity Mission

Mission Overview: 

Mission Overview LEO (700 km) Heliocentric Flight Earth - Mars Launch Crew Return HEO 30,000 –> 90,000 km (Circular Orbits) Pre-deployed Mars Lander 500 -> 90,000 km (Elliptical or Circular Orbits) Launch of NEP Transfer Vehicle Launch Of Crew XTV On-orbit Construction of Transfer Vehicle Launch for Crew Pickup Landing Rendezvous/Dock Of Crew XTV and Mars Transfer Vehicle Crew Delivery XTV (Possible Emergency Return Vehicle) Heliocentric Flight Mars - Earth Rendezvous/Dock Of Descent/Ascent Vehicle And Mars Transfer Vehicle >30 Day Surface Stay Mars Crew Transfer Vehicle Constant Thrust Power = 6 MW Efficiency = 60% Isp = 4000 sec Mass Return to Earth = 89 mt Courtesy: Jerry Condon/JSC

2026 Trajectory Point Design: 

2026 Trajectory Point Design Start at 700 km Earth orbit altitude July 31, 2026 Initial Mass: 271.6 mt Earth Mars Sun Escape Earth Spiral for 98.5 days November 7, 2026 Mass after spiral: 232.0 mt Capture at Earth June 23, 2028 Orbit altitude 90,000 km Spiral for 2.1 days to capture Mass after spiral: 89 mt Begin Spiral at Earth return July 21, 2028 Mass before spiral: 89.6 mt Begin Spiral Capture at Mars June 20, 2027 Mass before spiral: 160.8 mt Finish capture at Mars July 27, 2027 Spiral for 6.3 days Capture into 16,700 km orbit Mass after spiral: 158.3 mt Stay time 70 days in Mars orbit Begin Spiral Escape of Mars Sept. 5, 2027 Escape Mars Spiral for 6.1 days Sept. 11, 2027 Mass after spiral: 155.9 mt Close Approach to Sun Distance ~ 0.39 AU Mercury Mission Assumptions: Earth Departure Orbit: 700 km altitude Earth Return Orbit: 90,000 km altitude Mars Parking Orbit: 16,700 km altitude Stay Time in Mars Orbit: 70 days System Assumptions Power: 6 MW Specific Impulse (Isp): 4000 sec Thruster efficiency: 60% Tankage Fraction: 5% Courtesy: Melissa McGuire/GRC, Rob Falck/GRC 90,000 km Earth return 16,700 km Mars Parking Orbit

Artificial-Gravity Vehicle: 

Artificial-Gravity Vehicle Continuing serious concerns regarding human physiological effects of long-duration micro-gravity exposure Loss of bone mineral density Skeletal muscle atrophy Orthostatic hypertension Current countermeasures deemed ineffective (in particular w.r.t. bone mineral density loss) Propellant Tanks Main Thrusters Primary TVC via vehicle pointing Main Power Redundant Reactors Redundant Power Conversion Reactor Rad Shielding Main Power Radiators Flexible, Deployable Control Jets Spinup/spindown Steering Control Jets Zero-G Docking Port 125 m Crew Module Inflatable Pressure Shell Radiation Shielding Micrometeoroid Protection Life Support EVA Support Body-Mounted Radiator

Long-Stay Mission ExampleRef: 1998 Reference Mission Version 4.0: 

Long-Stay Mission Example Ref: 1998 Reference Mission Version 4.0 Charcteristics Split mission – predeployed surface habitat and ascent descent vehicle Solar Electric Propulsion concept (NTR and Chemical/Aerobrake investigated as options) Single round-trip vehicle for interplanetary crew transfers to and from Mars In-situ resources for fuel and as a level of consumables redundancy Shuttle derived launch vehicle (80 mt) used for LEO transportation Principal Results Incorporation of a round-trip crew transfer vehicle reduces system reliability requirement from five to three years, but requires an additional rendezvous in Mars orbit End-to-end Solar Electric Propulsion vehicle mission concept is shown to be a viable concept, but vehicle packaging and size remain tall-poles Total mission mass estimates for different space propulsion options: Solar Electric Propulsion: 467 mt Nuclear Thermal Propulsion: 436 mt Chemical/Aerobrake: 657 mt * High scientific duration (500+ days on Mars) Minimizes combined Earth-Mars and Mars-Earth transit duration and exposure of crew to interplanetary environment Maximizes reuse of mission elements: SEP and surface habitat (if desired) Vehicle design independent of mission opportunity (small variation (10%) in vehicle size for every Mars opportunity) Enables global surface access if desired

Mars Long-Stay MissionExample 2: DRM v 4.0: 

2016: SEP Vehicle Ascent/Descent Vehicle Surface Habitat 2018: Crew transit vehicle and SEP resupply launched Surface science concentrates on the search for life. Deep drilling, geology and microbiology investigations are supported by both EVA and by surface laboratories. Crew lands, spends 500 days on surface in predeployed Hab. Crew departs in Ascent/Descent Vehicle Ascent Vehicle rendezvous with Crew Transit Vehicle in Mars Orbit. Crew reaches Mars in 6-8 months Trans-Mars injection and Cruise Small crew “taxi” delivers crew to high Earth orbit 180 day return trip ends with direct entry and landing. Transfer to High Earth Orbit Trans-Mars injection and Cruise Transfer to High Earth Orbit Mars Long-Stay Mission Example 2: DRM v 4.0 Crew aerocaptures into Mars Orbit, transfers to Ascent/Descent Vehicle Ascent/Descent Vehicle aerocapturss into Mars orbit Habitat lander predeployed on Mars 2018: Crew launched

DRM 4.0 Vehicles: 

Mars Surface Habitat Supports a crew of six for up to 18 months on the surface of Mars Provides robust exploration and science capabilities May include an inflatable greenhouse/ laboratory module DRM 4.0 Vehicles Mars Transit Vehicle Transports crew from High Earth Orbit (HEO) to Mars orbit Crew must rendezvous with an ascent/ descent vehicle to visit the surface Transports crew from Mars orbit back to Earth Descent/Ascent Vehicle Transports six crew from Mars orbit to the surface and back to orbit Supports six crew for 30-days Uses locally produced propellants for ascent SEP LEO-HEO Tug Solar-electric propulsion enables low-consumption, 6-month spiral transit of large cargo elements from LEO to HEO Spirals back to LEO for re-fueling and re-use Not human-rated Crew Taxi Transports crew from LEO to HEO Can be deployed from shuttle, at ISS, or launched directly Returns to Earth for re-use

Key Mission Mode Findings: 

Key Mission Mode Findings The mission design process must properly balance human factors, science return, mission performance, and mission cost Mars missions are characterized by two mission types: “Opposition”/short stay (typically 500 day round trip) and “Conjunction”/long stay (typically 1000 day round trip). The total mass for opposition missions are roughly twice that of conjunction missions for similar crew sizes/payloads One-year round trip Mars missions are possible only in very favorable mission opportunities (2018, 2033, etc.) even accounting for aggressive technology advancements, and thus represent “one shot” approaches. Free-return trajectories, with reasonable durations, do not exist for Mars missions. Pre-deploying of mission assets can be used to reduce overall mission mass and provide functional redundancy of mission assets (thus reducing mission risk). Using local planetary resources works best when close to the point of manufacture and when returning to the same landing site. Missions in near-Earth space (Moon, Libration Points) can serve as stepping-stones (system, technologies, operations concepts) to further exploration activities.

Example Mars Architecture Trade Space: 

In-Space Propulsion Mars Capture Aerocapture? Mission Type Conjunction (long stay) vs. Opposition (short stay) Pre-Deploy Split vs. All-up Local Resource Utilization? Increasing “Performance” Decreasing vehicle wet mass, decreasing trip times, increasing payload, more challenging mission classes Chemical Nuclear Thermal Solar Electric / Chemical Solar Electric Nuclear Electric w/o AC w/ AC Conj (1952 Von Braun) Opp X Excessive Mass Conj Opp Split All Up All Up w/o ISRU w/ ISRU w/o AC w/ AC Conj Conj Opp w/o ISRU w/ ISRU Split All Up Opp Œ  Ž w/o AC w/ AC Conj Conj Opp Split All Up All Up w/o ISRU w/ ISRU Split All Up Opp   ‘ ’ ” “ • ‚ w/o AC w/ AC Conj Opp X Config.  w/o AC w/ AC Conj Split All Up Opp X Config. ‚ X Config.  X Excessive Size ? ? Questionable Feasibility Example Mars Architecture Trade Space Œ 1988 “Mars Expedition”  1989 “Mars Evolution” Ž 1990 “90-Day Study”  1991 “Synthesis Group”  1995 “DRM 1” ‘ 1997 “DRM 3” ’ 1998 “DRM 4” “ 1999 “Dual Landers” ” 1989 Zubrin, et.al* • 1994-99 Borowski, et.al  2000 SERT (SSP) ‚ 2002 NEP Art. Gravity “High Thrust” “Low Thrust” Hybrid *Assumptions not necessarily consistent

Mars Architecture Mass History: 

Mars Architecture Mass History 1 1988 Mars Expedition (Chem A/B) 2 1989 Mars Evolution (Chem A/B) 3 1990 90-Day Study (Chem A/B) 4 1991 Synthesis Group (NTR) 5 1995 DRM 1 Long Stay (NTR) 6 1997 DRM 3 Refinement (NTR) 7 1998 DRM 4 Refinement (NTR or SEP) 8 1999 Dual Landers (SEP) 9 2000 DPT/NEXT (NTR or SEP) ISS @ Assembly Complete (470 tons)

Key In-Space Transportation Findings: 

Key In-Space Transportation Findings Investment in space transportation technologies can provide significant mass savings (as compared to today’s chemical propulsion mission) Aerobraking: 40-45% In-Situ Resource Utilization: 21-25% High Efficiency In-Space Propulsion: 55% Combined savings can provide up to 68% savings Investment in space transportation technologies can provide significant reduction in crew exposure to the hazards of the deep space environment including radiation, zero-gravity, and overall mission duration. Electric propulsion is a common technology need across the Agency. Emphasis should be placed on technologies which are evolvable to meet the high-power needs of human missions. Chemical propulsion is a common technology need for lander/ascent vehicles across the Agency. Emphasis should be placed on high performance, low volume, and robust propulsion to increase payload and decrease volume. Aeroassist is a common technology need across the Agency. Advancement in aeroassist technologies are required for missions to the surface of Mars (aeroentry) as well as Earth return Long-term storage of cryogenic propellants is an essential technology Automated rendezvous and docking of mission elements in low-Earth orbit is needed

Key Human Health and Performance Findings: 

Key Human Health and Performance Findings The deep space and planetary surface radiation environment, as well as its effect on the human body, must be better understood, monitored, and mitigating/protective technologies developed. The effects of long term exposure to a micro-g environment are reasonably understood but no mitigating technologies or procedures have been found. In addition, the effects of long-term exposure to a hypo-g environment are poorly understood. Development and demonstration of advanced medical care, consistent with long term missions and risk, has yet to occur. “Abort to Earth” is not always feasible. To date, the Bioastronautics community has identified 55 risks and approximately 250 critical questions for a Mars mission, requiring approximately 185 studies to resolve ISS can be an important testing venue but only if the number of individual crew members is increased (for statistical significance); total duration on-board could be as little as 3 months. Ground-based experiments can answer a significant number, but not all, of these questions. Missions in Near-Earth space can be conducted prior to resolving many of these questions.

Key Advanced Life Support Findings: 

Key Advanced Life Support Findings Closing the life-support air and water loops with low expendables is a key leveraging technology for long duration human exploration missions Current food preservation technology is not capable of providing nutritionally viable food for the longer mission durations under study. Food production technologies under the environmental conditions of these missions is not developed to the point of being the primary source of food. Power requirements for both closed loop life support and food production can be significant, indicating that advanced life support and advanced power systems are closely coupled.

Key Surface Systems Findings: 

Key Surface Systems Findings Short missions (days or weeks) can accomplish useful objectives with local surface mobility capabilities (extra-vehicular activity suits and unpressurized rovers). Long surface missions can be accomplished using in-situ resource utilization for mission consumables (EVA O2, regenerate fuel cell reactants, and life support backup) A “power rich” infrastructure for base and mobile operations is critical for science and mission success All missions are significantly enhanced by the addition of advanced surface mobility and robotic assistance. Surface mobility reduces the time spent “commuting” to and from work sites. Surface mobility and robotic assistants can increase the mass and volume of equipment that can be carried to a work site. Robotic assistants can offload tasks from humans. Advances in EVA systems are required for both zero-g and planetary surface applications. Reduced maintenance and operational cost Improved dexterity and mobility Reduced mass and increased durability

Key Space Power Findings: 

Key Space Power Findings Lightweight megawatt-class nuclear power systems (~1-3 MWe units, 4-8MWe total) enable low-mass, fast-transit Mars missions. Small nuclear power modules (~30 kWe) enable extended Mars surface stays and in-situ propellant production, as well as being highly desirable for overnight stays on the Moon. High-power solar power (~0.5 – 2.0 MWe) concepts can provide low-mass transportation (cargo tugs) for both Near-Earth exploration as well as Mars mission departure. Solar / fuel cell concepts, with effective dust mitigation techniques, can potentially provide adequate power for short-stays on Mars. However, “dust storm” solar illumination attenuation may be critical factor. High energy density mobile power systems significantly enhances advanced surface mobility and robotic assistance capabilities and science objectives Energy density provided by advanced regenerative fuel cells is necessary for many phases of exploration missions (propulsive maneuvers, initial operations, etc.)

Key Cross-Cutting Technologies Findings: 

Key Cross-Cutting Technologies Findings Utilizing commodities produced from local planetary resources (oxygen, water, etc.) can provide great mission mass leverage as well as risk reduction (functional redundancy) Science return can be best achieved through a combination of robotic and human exploration Reuse of space-based systems can provide significant mass leverage, but at the same time pose a technology and operational risk Remoteness and time delays of deep-space human exploration missions necessitates new operational approaches and concepts – must operate differently from past or current modes.

Enabling Capabilities/Technologies: 

Enabling Capabilities/Technologies Affordable heavy lift capability Advanced structures High acceleration, high life cycle, reusable in-space main engine Advanced power & propulsion Cryogenic fluid management Large aperture systems* Formation flying* High bandwidth communications Entry, descent & landing Closed-loop life support and habitability Extravehicular activity systems Autonomous systems and robotics Scientific data collection/analysis* Biomedical risk mitigation Transformational spaceport & range technologies Automated rendezvous & docking Planetary in situ resource utilization Heavy lift Advanced structures Reusable in-space engines In-space power & propulsion Cryo fluid management Large aperture systems* High-bandwidth communications Planetary entry, decent & landing Environmental control & life support systems Extravehicular activity systems Autonomous systems/robotic Science data analysis* Automated rendezvous & docking ISRU Aldridge Commission (6/04) CRAI Team Assessment (8/03) Low-cost heavy lift Advanced interplanetary propulsion Cryogenic fluids management Automated rendezvous & docking Accurate and safe planetary landings Aeroassist Health & human performance Advanced life support Advanced habitation systems EVA & surface mobility In-situ consumable production Advanced power generation, management & storage NASA Mission Study Findings (89-92) *Associated with specific mission scientific goals

The Value of Technology InvestmentsMars Mission Example: 

The Value of Technology Investments Mars Mission Example Ì Advanced Propulsion Ì Closed Loop Life Support Ì Advanced Materials Ì Maintenance & Spares Ì Advanced Avionics Ì Aerocapture All Propulsive Chemical Today NOTES: Results are cumulative and thus trends will be different for different technology combinations/sequences The change between points shows the relative mass savings for that particular technology 2018 One-Year Round-Trip Mission, Crew of 4, Lander pre-deployed Ref. Johnson Space Center

Potential Uses of Space Resources for Robotic & Human Exploration: 

Potential Uses of Space Resources for Robotic & Human Exploration Mission Consumable Production Propellants for Landers, Hoppers, & Aerial Vehicles Fuel cell reagents for mobile (rovers, EVA) & stationary backup power Life support consumables (oxygen, water, buffer gases) Gases for science equipment and drilling Bio-support products (soil, fertilizers, etc.) Feedstock for in-situ manufacturing & surface construction Manufacturing w/ Space Resources Spare part manufacturing Locally integrated systems & components (especially for increasing resource processing capabilities) High-mass, simple items (chairs, tables, chaises, etc.) Surface Construction Radiation shielding from in-situ resources or products (Berms, bricks, & plates; water; hydrocarbons) Shielding from micro-meteoroid and landing/ascent plume debris Habitat and equipment protection Roads, landing pads, site preparation, etc. Space Power & Utilities Storage & distribution of mission consumables Thermal energy storage & use Solar energy (PV, concentrators, rectennas) Chemical energy (fuel cells, combustion, catalytic reactors, etc.)

Specific ISRU Examples from NASA Architectures: 

Specific ISRU Examples from NASA Architectures Architecture mass reduction Mars Ascent Vehicle propellant production results in >20% decrease in overall mission mass “Dissimilar” redundancy Oxygen production for life support Water caches for life support Energy caches (fuel cell reactants) for power production Simplification and increased reliability of systems Oxygen production allows “Cryo PLSS” / venting suit for EVA Elimination of entire flight elements Added functionality (& mass) possible for Mars Ascent Vehicle and elimination of “Earth Entry Vehicle”

ISRU Dependencies: 

ISRU Dependencies The use of space resources is: Architecture dependant: Long stay vs short stay (mission consumable mass increases with stay time) Pre-deploy vs all in one mission (pre-deploy allows longer production times but requires precision landing) Multiple mission to same destination vs single missions (multiple missions enables gradual infrastructure and production rate build up) High orbit vs low orbit rendezvous (increase in Delta-V increases benefit of in-situ produced propellant) Reuse vs single mission (reuse allows for single stage vs two stage landers) Customer dependant: ISRU is only viable if use is designed into subsystems that utilize the products (propellants, radiation shielding, energy storage, surface equipment, spare parts, etc.) Time phased: Early missions must require minimum infrastructure and provide the biggest mass/cost leverage (mission consumables have biggest impact) Surface construction and manufacturing will start with simple/high leverage products and expand to greater self-sufficiency capability ISRU is evolutionary and needs to build on lessons learned from previous work and show clear benefit metrics

Core ISRU Technologies Enable Multiple Applications: 

Core ISRU Technologies Enable Multiple Applications CO2 & N2 Acquisition & Separation Sabatier Reactor RWGS Reactor CO2 Electrolysis Methane Reforming H2O Separators H2O Electrolysis H2O Storage Heat Exchangers Liquid Vaporizers O2 & Fuel Storage (0-g & reduced-g) O2 Feed & Transfer Lines O2/Fuel Couplings Fuel Cells O2/Fuel Igniters & Thrusters Life Support Systems for Habitats & EVA Fuel Cell Power for Spacecraft, Rovers & EVA In-Situ Production Of Consumables for Propulsion, Power, & ECLSS Non-Toxic O2-Based Propulsion Water – H2/O2 Based Propulsion Core Technologies 0-g & Reduced-g Propellant Transfer Planetary Resource Utilization Maximizes Benefits, Flexibility, & Affordability

Surface Infrastructure Based On Common ISRU-Supplied Fluid: 

Surface Infrastructure Based On Common ISRU-Supplied Fluid Life Support Systems for Habitats & EVA Fuel Cell Power for Rovers & EVA In-Situ Production Of Consumables Human Ascent Propulsion Production Rate: Human Mars: 2-4 kg of O2/hr – 24 hr Habitat ECLSS Usage Rate: 0.4 kg of O2/hr (crew 6) EVA ECLSS Usage Rate: 0.2 kg of O2/hr (crew 2) EVA Rover (600 W) Human Rover (10 KW) Non-Toxic O2-Based Propulsion Usage Rate: 0.5 kg of O2/hr Usage Rate: 9.4 kg of O2/hr Production, Storage & Use of Common Fluids EVA Suit (50-100 W) Usage Rate: <0.08 kg of O2/hr JSC-Energy Systems Division Usage Rate: 20,000 kg O2 Oxygen (O2) Water (H2O) Fuel (H2,CH4, etc.) Nitrogen (N2)

Mars ISRU Demonstration Rationale & Approach: 

Mars ISRU Demonstration Rationale & Approach Investigate Environment/Resources of interest Determining quantity and form of surface/sub-surface water is critical Maximum leverage if water is available on Mars (methane and oxygen) Significant leverage even if water not available (oxygen only) Location and acquisition of water remains the big unknown in ISRU planning Science missions will help determine & locate possible recoverable water: Marsis--> SHARAD--> Phoenix--> MSL--> other orbiter Demonstrate ISRU Hardware/Systems in relevant environment Mars environment interaction with ISRU plant can’t be fully simulated on Earth Extended periods of test to simulate long duration flights will be difficult to perform Perform ISRU demonstrations in step-wise approach to increase confidence in environment/resource understanding and reduce mission application uncertainties Experiment development time, 26 month gaps in missions, trip times, and extended surface operations mean lessons learned from one mission can only influence missions 2 or 3 opportunities (4 or 6 years) later Parallel investigations of atmospheric and regolith/water-based processing with convergence before human mission Utilize step/spiral development of identified ISRU Capabilities: Mission consumable production Water extraction & processing Regolith processing for manufacturing of spare parts & other infrastructure items Regolith manipulation and processing for construction (landing pads, radiation shielding, berms for nuclear reactor or plume debris mitigation, etc.) Bio-plant growth support

ISRU Challenges: 

ISRU Challenges Maximize benefit of using resources, in the shortest amount of time, while minimizing crew involvement and Earth delivered infrastructure Early Mass, Cost, and/or Risk Reduction Benefits Processing and manufacturing techniques capable of producing 100’s to 1000’s their own mass of product in their useful lifetimes, with reasonable quality. Construction and erection techniques capable of producing complex structures from a variety of available materials. In-situ manufacture of spare parts and equipment with the minimum of required equipment and crew training Methods for energy efficient extracting oxygen and other consumables from lunar or Mars regolith Methods for mass, power, and volume efficient delivery and storage of hydrogen Long-duration, autonomous operation Autonomous control & failure recovery (No crew for maintenance; Non-continuous monitoring) Long-duration operation (ex. 500 days on Mars surface for propellant production) High reliability and minimum (zero) maintenance High reliability due to no (or minimal) maintenance capability for pre-deployed and robotic mission applications Networking/processing strategies (idle redundancy vs over-production/degraded performance) Development of highly reliable thermal/mechanical cycle units (valves, pumps, heat exchangers, etc.) Development of highly reliable, autonomous calibration control hardware (sensors, flowmeters, etc.)

ISRU Challenges (Cont.): 

ISRU Challenges (Cont.) Operation in severe environments Efficient excavation of resources in extremely cold (ex. Lunar permanent shadows), dusty/abrasive, and/or micro-g environments (Asteroids, comets, Mars moons, etc.) Methods to mitigate dust/filtration for Mars atmospheric processing Resource Unknowns Is water/ice, hydrogen, or both located in lunar polar and permanently shadowed crater? Is the ice/hydrogen accessible/useable? How much water is in the Mars regolith and can it be efficiently extracted? Is subterranean water present, what form is it in, and where? What are the material chemical and physical properties of Phobos & NEO asteroids? How much water is available and in what form/concentration is it found (ice, hydrated clays, …)?