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The Systems Integration, Modeling and Analysis (SIMA) element1 of the National Aeronautics and Space Administration (NASA) Advanced Life Support (ALS) Project conducts on-going studies to determine the most efficient means of achieving a human mission to Mars. Life support for the astronauts constitutes an extremely important part of the mission and will undoubtedly add significant mass, power, volume, cooling and crew time requirements to the mission. Equivalent system mass (ESM) is the sum of these five parameters on an equivalent mass basis and can be used to identify potential ways to reduce the overall cost of the mission. SIMA has documented several reference missions in enough detail to allow quantitative studies to identify optimum ALS architectures. The Mars Dual Lander Mission, under consideration by the Johnson Space Center (JSC) Exploration Office, is one of those missions.

This paper addresses the effect of waste processing on advanced life support (ALS) system design. Waste processing is a critical component of an advanced life support system. It must take all life support system wastes and either convert them into useful products or into a form in which they can be discarded. Waste can be treated as soon as it is produced, stored as is, or processed into an intermediate form for further treatment. The decisions made will affect the cost-effectiveness of the system. Strategies must be developed to meet waste processing requirements for specific mission scenarios.

New information is presented on conceptual designs of bioregenerative life support systems, with subsystems defined, sizes estimated, and configurations developed.1 Components are sized by comparison with design data from Spacelab, the space station, commercial practice, and research on new technologies. Designs were developed on a Microstation CAD system, importing existing models such as space station modules where available. Layouts consider component mass and power as well as connections and access requirements. In addition, current efforts in the NASA CELSS Breadboard Facility (CBF) at Kennedy Space Center are described, which may validate some of these design concepts. Design optimization for the next-generation Breadboard Facility is discussed.

Exploration missions are expected to reach the 100-day class by Spiral 3, 1000-day class for Spiral 4, and perhaps longer for later spirals. Depending on the equivalencies achieved, bioregenerative life support can offer cost effectiveness as well as autonomy for 1000-day class missions, and will need to be demonstrated in space on Spiral 3 missions to support application to the longer missions. Several other technologies can also reduce the cost of life support in space by factors in the single digits, or perhaps even an order of magnitude. However, these improvements will not come easily, requiring advances in both life support technology and mission infrastructure. Equivalencies (infrastructure cost factors) are recommended for the 2020 to 2030 timeframe anticipated for Spirals 3 and 4. Cost effectiveness of several life support related technologies are assessed, and a life support metric is calculated based on this data.

Three distinct food system paradigms have been envisioned for long-term space missions. The Skylab, Mir and ISS food systems were based on single-serving prepackaged foods, ready to rehydrate and heat. Bioregenerative food systems, derived from crops grown and processed at the planetary station, have been studied at JSC and KSC. The US Antarctic Program’s Amundsen-Scott South Pole Base uses the third paradigm: bulk packaged food ingredients delivered once a year and used to prepare meals on the station. The packaged food ingredients are supplemented with limited amounts of fresh foods received occasionally during the Antarctic summer, trace amounts of herb and salad crops from the hydroponic garden, and some prepackaged ready to eat foods, so the Pole system is actually a hybrid system; however, it is worth studying as a bulk packaged food system because of the preponderance of bulk packaged food ingredients used.

Work defining advanced life support (ALS) technologies and evaluating their applicability to various long-duration missions has continued. Time-dependent and time-invariant costs have been estimated for a variety of life support technology options, including International Space Station (ISS) environmental control and life support systems (ECLSS) technologies and improved options under development by the ALS Project. These advanced options include physicochemical (PC) and bioregenerative (BIO) technologies, and may in the future include in-situ-resource utilization (ISRU) in an attempt to reduce both logistics costs and dependence on supply from Earth. PC and bioregenerative technologies both provide possibilities for reducing mission equivalent system mass (ESM). PC technologies are most advantageous for missions of up to several years in length, while bioregenerative options are most appropriate for longer missions. ISRU can be synergistic with both PC and bioregenerative options.