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Providing water necessary to maintain life support has been accomplished in spacecraft vehicles for over forty years. This paper will investigate how previous U.S. space vehicles provided potable water. The water source for the spacecraft, biocide used to preserve the water on-orbit, water stowage methodology, materials, pumping mechanisms, on-orbit water requirements, and water temperature requirements will be discussed. Where available, the hardware used to provide the water and the general function of that hardware will also be detailed. The Crew Exploration Vehicle (CEV or Orion) water systems will be generically discussed to provide a glimpse of how similar they are to water systems in previous vehicles. Conclusions, questions, and recommendations on strategies that could be applied to CEV based on previous spacecraft water system lessons learned will be made.

Silver biocide offers a potential advantage over iodine, the current state-of-the-art in US spacecraft disinfection technology, in that silver can be safely consumed by the crew. As such, silver may reduce the overall complexity and mass of future spacecraft potable water systems, particularly those used to support long duration missions. A primary technology gap identified for the use of silver biocide is one of material compatibility. Wetted materials of construction are required to be selected such that silver ion concentrations can be maintained at biocidally effective levels.

The stability of silver biocide, used to keep drinking water on the CEV potable water disinfected, is unknown as the system design is still in progress. Silver biocide in water can deplete rapidly when exposed to various metal surfaces. Additionally, silver depletion rates may be affected by the surface-area-to-volume (SA/V) ratios in the water system. Therefore, to facilitate the CEV water system design, it would be advantageous to know the biocide depletion rates in water exposed to the surfaces of these candidate metals at various SA/V ratios. Certain surface treatments can be employed to reduce the depletion rates of silver compared to the base metal.

A system of amine-based carbon dioxide (CO2) and water vapor sorbent in pressure-swing regenerable beds has been developed by Hamilton Sundstrand and is baselined for the Orion Atmosphere Revitalization System (ARS). In two previous years at this conference, reports were presented on extensive Johnson Space Center (JSC) testing of the technology, which was performed in a representative environment with simulated human metabolic loads. The next step in developmental testing at JSC was to use real human loads in the spring of 2008.

Recovery of potable water from wastewater is essential to the success of long-duration human missions to the moon and Mars. Honeywell International and a team from the NASA Johnson Space Center (JSC) are developing a wastewater processing subsystem that is based on centrifugal vacuum distillation. The wastewater processor, which is referred to as the cascade distillation subsystem (CDS), uses an efficient multistage thermodynamic process to produce purified water. A CDS unit employing a five-stage distiller engine was designed, built, and delivered to the NASA JSC Advanced Water Recovery Systems Development Facility for performance testing; an initial round of testing was completed in fiscal year 2008 (FY08). Based, in part, on FY08 testing, the system is now in development to support an Exploration Life Support Project distillation comparison test that is expected to begin in 2009.

Since the early 1980’s, the Shuttle Extra Vehicular Activity (EVA) glove design has evolved to meet the challenge of space based tasks. These tasks have typically been satellite retrieval and repair or EVA based flight experiments. With the start of the International Space Station (ISS) assembly, the number of EVA based missions is increasing far beyond what has been required in the past; this has commonly been referred to as the “Wall of EVA’s”. To meet this challenge, it was determined that the evolution of the current glove design would not meet future mission objectives. Instead, a revolution in glove design was needed to create a high performance tool that would effectively increase crewmember mission efficiency. The results of this effort have led to the design, certification and implementation of the Phase VI EVA glove into the Shuttle flight program.

The NASA/Industry Shuttle EMU team initiated an EMU program activity in 1988 to reduce EMU criticality 1 failure causes, reduce ground operations costs, and also to enhance on-orbit operational Extravehicular Activity (EVA) capability. Replacement/refurbishment hardware is being developed, certified, and delivered. System level life extention testing is expected to extend the Life Limited Components replacement schedule. Goals of this program are to achieve a 25 percent reduction in ground turn-around man-hours and processing time between missions and to extend Extravehicular Activity (EVA) on-orbit capabilities expected to be necessary to support Space Station Freedom assembly and contingency EVA operations. This paper identifies and describes tasks being implemented with expected benefits to NASA-manned spaceflight programs.

Recent Shuttle extravehicular activity (EVA) missions have shown the need for improved thermal performance in Space Suit Assembly (SSA) gloves to successfully complete assembly of the International Space Station (ISS). Passive thermal design improvements have been successfully incorporated, however, additional improvements are still possible. An Active Heated Glove Assembly was developed to aid in the prevention of cold hands and fingers during periods of rest and low metabolic activity. Environmental vacuum tests have shown that the system accomplishes its goals and measurably increases glove thermal performance.

The continuous development of Extravehicular Activity (EVA) spacesuit gloves has lead to an effective solution for performing EVA to date. Some aspects of the current EVA gloves have been noted to affect crew performance in the form of limited dexterity and accelerated onset of fatigue from high torque mobility joints. This in conjunction with the fact that more frequent and complex EVAs will occur with the fabrication and occupation of Space Station Freedom, suggest the need for improved spacesuit gloves. Therefore, several efforts have been conducted in the recent past to enhance the performance of the spacesuit glove. The following is a description of the work performed in these programs and their impact on the design and performance of EVA equipment. In the late 1980's and early 1990's, a spacesuit glove design was developed that focused on building a more conformal glove with improved mobility joints that could function well at a higher operating pressure.

The shortened liquid cooling/warming garment (SLCWG) developed by the University of Minnesota group was compared with the standard NASA liquid cooling/ventilating garment (LCVG) garment during physical exertion in comfort (24°C) and hot (35°C) chamber environments. In both environmental conditions, the SLCWG was just as effective as the LCVG in maintaining rectal temperature (Tre) in a thermal comfort range; sweat production on the face was less; and subjective perception of overall and local body comfort was higher. The findings indicate that the SLCWG produces the same or greater comfort level as that achieved with the LCVG's total coverage of the body surface.