This content is not included in your SAE MOBILUS subscription, or you are not logged in.
Impacts of System Decisions at the Life Support, EVA, and Habitability Interfaces
ISSN: 0148-7191, e-ISSN: 2688-3627
Published July 11, 2005 by SAE International in United States
Annotation ability available
Technology developers understand the need to optimize technologies for human missions beyond Earth. Greater benefits are achievable when systems that share common interfaces are optimized as an integrated unit, including taking advantage of possible synergies or removing counterproductive efforts at the mission level. Life support, extravehicular activity (EVA), and habitability are three systems that have significant interfaces with the crew, and thus share many common interfaces with each other.
Technologies and architectures developed for these systems need to account for the effect that design decisions will have on each of the other systems. Many of these impacts stem from the use of water by the crew and the way that the life support system provides and processes that water. Other resources, especially air-related, can have significant impacts as well. Mission and system designers should be aware of the effects that requirements and subsystem decisions at all levels can have on the total mission.
One example of an important decision is the way resources are provided to an EVA portable life support system (PLSS) from the life support system. Another example is the impact of including or neglecting waste recovery from a PLSS system on resupply requirements of the life support system. Important habitability decisions include hygiene systems, such as showers, sponge baths, or pre-hydrated wipes, and clothing options including resupply, advanced materials, and laundry options, and the water recovery architecture best suited to these choices. The method of providing food can make demands on resupply to the life support system, but significant variations occur depending on dehydration levels and cooking methods.
Each of these decisions also needs to be considered within the framework of spiral development as espoused by the NASA Exploration Systems Mission Directorate (ESMD). In spiral development, “a desired capability is identified, but the end-state requirements are not known at program initiation. Requirements are refined through demonstration, risk management and continuous user feedback.” (6) For example, ESMD Spiral 2 missions have a manned surface duration of 4 to 7 days, but a requirement (ESS0120) that states “The Exploration System of Systems shall demonstrate the capabilities necessary to prepare for long-duration human exploration of the moon.” (10) Within this additional layer of integrating system decisions between missions, the best selection may not be one that is optimized for the current mission, but rather one that has potential for testing and technology development or demonstration for future missions and requirements.
CitationAnderson, M., Thomas, G., Chambliss, J., and Conger, B., "Impacts of System Decisions at the Life Support, EVA, and Habitability Interfaces," SAE Technical Paper 2005-01-2907, 2005, https://doi.org/10.4271/2005-01-2907.
- Bagian, et al. Advanced Technology for Human Support in Space. National Academy of Sciences Committee on Advanced Human Support in Space. National Academies Press. Washington, DC 1997.
- Case, Carl, Capps Stephen. “The Doorlock/Node, A promising SSF Airlock Alternative” AIAA-1993-4180. AIAA Space Programs and Technologies Conference and Exhibit. Huntsville, AL. September 21–23, 1993.
- Cohen, Marc M. “Suitport Extra-vehicular Access Facility.” US Patent no. 4,842,224. June 27, 1989.
- Cohen, Marc M. “The Suitport’s Progress” AIAA 95–1062. AIAA Space Medicine and Life Science Conference, Houston, Texas, USA, 3–5 April 1995.
- Colombo, Gerald, Putnam, David Lunsford, Teddie Streech, Neil Wheeler, Richard Reimers Harold. “Single Phase Space Laundry Development.” SAE 932092. 1993.
- Defense Acquisition University Glossary Version 11. http://deskbook.dau.mil/jsp/GlossaryIndex.jsp
- Denvir, Adrian, Rogers, Tom Hitchens, Duncan Jeng, King-Tsia Bourland, Deborah Reimers Harold. “An Ozone-Based Laundry and Laundry Wash Water Recovery System.” SAE 972426. SAE 27th International Conference on Environmental Systems, Lake Tahoe, NV. July 1997.
- Drysdale, Alan, Garton, Harry Barker, Roger Thompson, Donald Scruggs, Barbara Fratto Lisa. ”Clothing Systems for Long-Duration Space Missions.” SAE 2004-01-2580.SAE 34th International Conference on Environmental Systems, Colorado Springs, CO, July 2004.
- Dudley-Rowley,Marilyn, Cohen, Marc Flores Pablo. “1985 NASA-Rockwell Space Station Crew Safety Study: Results from MIR”. OPS-Alaska. 18 May 2004. http://pweb.jps.net/~md-r/spaceEx/SpaceStationCrewSafetyStudy.pdf
- Exploration System of Systems Technical Requirements Document. ESMD-RQ-0010 Rev D. NASA Exploration Systems Directorate. February 22, 2005. http://exploration.nasa.gov/documents/ESMD-RQ-0010_Rev_D_ESS_Technical.pdf
- Focused Trade Study Final Report. ESMD-RQ-0005. NASA Exploration Systems Directorate. 2005.
- Garland, Jay. “Cleansing Agents for Human Hygiene in Space Travel: Considerations for Biological Processing of Wastewater.” SAE 2002-01-2352. SAE 32nd International Conference on Environmental Systems. San Antonio, TX. July 2002.
- Golub, Morton, Wydeven Theodore. Waste Streams in a Typical Crewed Space Habitat: An Update. NASA-TM-103888. National Aeronautics and Space Administration Ames Research Center. Moffet Field, CA. February 1992.
- Hanford, Anthony. Advanced Life Support Baseline Values and Assumptions Document. NASA CR-2004-208941. August 2004.
- Larson, Wiley J., Pranke Linda K., Ed. Human Spaceflight: Mission Analysis and Design. McGraw-Hill.
- Michalek, William, Grounds Phyllis. “Single-Phase Laundry for Long Duration Space Missions.” SAE 901316. 1990.
- NASA Extravehicular Mobility Unit (EMU) Life Support Subsystem (LSS) and Space Suit Assembly (SSA) Data Book, Rev. K. Contract No. NAS9-97150, DRL No. 14. NASA Johnson Space Center, Houston, TX. September 2004.
- Portree, David, Trevino Robert C.. Walking to Olympus: An EVA Chronology. National Aeronautics and Space Administration Monographs in Aerospace History #7. October 1997. http://spaceflight.nasa.gov/spacenews/factsheets/pdfs/EVACron.pdf
- The Vision for Space Exploration. National Aeronautics and Space Administration. February 2004. http://www.nasa.gov/pdf/55583main_vision_space_exploration2.pdf
- Wydeven, Theodore, Golub Morton. Generation Rates and Chemical Composition of Waste Streams in a Typical Crewed Space Habitat. NASA-TM-102799. National Aeronautics and Space Administration Ames Research Center. Moffet Field, CA. August 1990.
- Yeh, Jannivine, Jeng, Frank Brown, Cheryl Lin, Chin H. Ewert Michael K.. (2001) “Advanced Life Support Sizing Analysis Tool (ALSSAT) Using Microsoft Excel,” SAE 2001-01-2304. 31st International Conference on Environmental Systems, Orlando, FL, July 2001.
- Yeh, Jannivine, Lin, Chin H. Brown, Cheryl Ewert, Michael K. Jeng Frank F.. (2004) “ALSSAT Development Status and Its Applications in Trade Studies” SAE 2004-01-2438”. SAE 34th International Conference on Environmental Systems, Colorado Springs, CO, July 2004.