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The Vapor Phase Catalytic Ammonia Removal (VPCAR) system is being developed to recycle water for future NASA Exploration Missions [1,2,3,4,5]. Reduced gravity testing of the VPCAR System has been initiated to identify any potential problems with microgravity operation. Two microgravity testing campaigns have been conducted on NASA's C-9B Reduced Gravity Aircraft. These tests focused on the fluid dynamics of the unit's Wiped-Film Rotating Disk (WFRD) evaporator. The experiments used a simplified system to study the process of forming a thin film on a rotating disk. The configuration simulates the application of feed in the VPCAR's WFRD evaporator. The first round of aircraft testing, which was completed in early 2006, indicated that a problem with microgravity operation of the WFRD existed. It was shown that in reduced gravity the VPCAR wiper did not produce a uniform thin film [6]. The film was thicker near the axis of rotation where centrifugal forces are small.

The Vapor Phase Catalytic Ammonia Removal (VPCAR) technology has been previously discussed as a viable option for the Exploration Water Recovery System. This technology integrates a phase change process with catalytic oxidation in the vapor phase to produce potable water from exploration mission wastewaters. A developmental prototype VPCAR was designed, built and tested under funding provided by a National Research Announcement (NRA) project. The core technology, a Wiped Film Rotating Device (WFRD) was provided by Water Reuse Technologies under the NRA, whereas Hamilton Sundstrand Space Systems International performed the hardware integration and acceptance test of the system. Personnel at the Ames Research Center performed initial systems test of the VPCAR using ersatz solutions. To assess the viability of this hardware for Exploration Life Support (ELS) applications, the hardware has been modified and tested at the MSFC ECLS Test Facility.

Direct osmotic concentration (DOC) is a membrane treatment process for reclamation of space craft wastewater. It incorporates a novel system architecture that includes a forward osmosis (FO) and reverse osmosis (RO) subsystem for hygiene (gray) water, and a membrane distillation subsystem for the treatment of urine and humidity condensate. The products of these subsystems are combined and then post-treated by a catalytic oxidation subsystem. This paper documents progress made during the second year of a three year Rapid Technology Development Team (RTDT) effort.

Terraforming of Mars is the long-term goal of colonization of Mars. However, this process is likely to be a very slow process and conservative estimates involving a synergetic, technocentric approach suggest that it may take around 10,000 years before the planet can be parallel to that of Earth and where humans can live in open systems (Fogg, 1995). Hence, for the foreseeable future, any missions will require habitation within small confined habitats with high biomass to atmospheric mass ratios, thereby requiring that all wastes be recycled. Processing of the wastes will ensure predictability and reliability of the ecosystem and reduce resupply logistics. Solid wastes, though smaller in volume and mass than the liquid wastes, contain more than 90% of the essential elements required by humans and plants.

The future of manned space exploration will be determined through a process which balances the innate need of humanity to explore its surroundings and the costs associated with accomplishing these goals. For NASA this balance is derived from economics and budgetary constraints that hold it accountable for the expenditure of public funds. These budgetary realities demand a reduction in cost and expenditures of exploration and research activities. For missions venturing out to the edge of habitability, the development of cost effective life support approaches will have a significant influence on mission viability. Over the past several years a variety of mission scenarios for Lunar and Mars missions have been developed. The most promising of these attempt to provide basic mission requirements at a minimum cost. As a result these missions are extremely power limited.

Direct osmotic concentration (DOC) is an integrated membrane treatment process designed for the reclamation of spacecraft wastewater. The system includes forward osmosis (FO), membrane evaporation, reverse osmosis (RO) and an aqueous phase catalytic oxidation (APCO) post-treatment unit. This document describes progress in the third year of a four year project to advance hardware maturity of this technology to a level appropriate for human rated testing. The current status of construction and testing of the final deliverable is covered and preliminary calculations of equivalent system mass are funished.

The Vapor Phase Catalytic Ammonia Removal (VPCAR) Technology has undergone long duration testing at MSFC. The results of this testing revealed several areas in which the VPCAR Technology could be improved and those improvements are summarized here. These improvements include the replacement of several parts with units that are more durable, redesign of several pieces which proved to have mechanical weaknesses, and incorporation of some new designs in order to prevent other potential problems.

For wastewater treatment applications, membrane processes are known to provide excellent treatment but are subject to failure due to membrane fouling. The Direct Osmotic Concentration (DOC) system evaluated in this study provides a membrane based primary treatment process capable of overcoming this problem. A full scale test apparatus containing full scale test module membrane cells has been developed and has undergone preliminary testing that provides a basis for comparison with other primary water recycle process concepts. This study confirms and extends the initial testing of this hardware and determines the required improvements to the existing test mo dules. These improvements, in addition to future testing, are intended to complete the validation of the concept and mature the hardware to the point that human rated test equipment design and development can be based directly on the test module derived data.

The purification of waste water is a critical element of any long-duration space mission. The Vapor Phase Catalytic Ammonia Removal (VPCAR) system offers the promise of a technology requiring low quantities of expendable material that is suitable for exploration missions. NASA has funded an effort to produce an engineering development unit specifically targeted for integration into the NASA Johnson Space Center's Integrated Human Exploration Mission Simulation Facility (INTEGRITY) formally known in part as the Bioregenerative Planetary Life Support Test Complex (Bio-Plex) and the Advanced Water Recovery System Development Facility. The system includes a Wiped-Film Rotating-Disk (WFRD) evaporator redesigned with micro-gravity operation enhancements, which evaporates wastewater and produces water vapor with only volatile components as contaminants. Volatile contaminants, including organics and ammonia, are oxidized in a catalytic reactor while they are in the vapor phase.

An energy-efficient lyophilization technique is being developed to recover water from highly contaminated spacecraft waste streams. In the lyophilization process, water in an aqueous waste is frozen and then sublimed, separating the waste into a dried solid material and liquid water. This technology is ideally suited to applications such as the Mars Reference Mission, where water recovery rates approaching 100% are desirable but production of CO2 is not. Candidate wastes include feces, concentrated brines from water processors, and other solid wastes that contain water. To operate in microgravity, and to minimize power consumption, thermoelectric heat pumps can be used in place of traditional fluid cycle heat pumps. A mathematical model of a thermoelectric lyophilizer is described and used to generate energy use and processing rate estimates.

This project is a Phase III SBIR contract between NASA and Water Reuse Technology (WRT). It covers the redesign, modification, and construction of the Wiped-Film Rotating-Disk (WFRD) evaporator for use in microgravity and its integration into a Vapor Phase Catalytic Ammonia Removal (VPCAR) system. VPCAR is a water processor technology for long duration space exploration applications. The system is designed as an engineering development unit specifically aimed at being integrated into NASA Johnson Space Center's Bioregenerative Planetary Life Support Test Complex (BIO-Plex). The WFRD evaporator and the compressor are being designed and built by WRT. The balance of the VPCAR system and the integrated package are being designed and built by Hamilton Sundstrand Space Systems International, Inc. (HSSSI) under a subcontract with WRT. This paper provides a description of the VPCAR technology and the advances that are being incorporated into the unit.

Direct osmotic concentration (DOC) has been identified as a potential wastewater treatment process for potable reuse in advanced life support systems (ALSS). As a result, further development of the DOC process is being supported by a NASA Rapid Technology Development Team (RTDT) program. DOC is an integrated membrane system combining three unique membrane separation processes including forward osmosis (FO), membrane distillation (MD), and reverse osmosis (RO) that is designed to treat separate wastewater streams comprising hygiene wastewater, humidity condensate, and urine. An aqueous phase catalytic oxidation (APCO) process is incorporated as post treatment for the product water. In an ongoing effort to improve the DOC process and make it fully autonomous, further development of the three membrane technologies is being pursued.

This paper describes the results of ground testing of a scroll pump with a potential of being a substitute for the current vacuum pump of the Vapor Phase Catalytic Ammonia Reduction (VPCAR). Assessments of the pressure-time, pump-down time, pump power and the pump noise were made for three configurations of the pump the first of which was without the gas ballast, the second with the gas ballast installed but not operating and the third with the gas ballast operating. The tested scroll pump exhibited optimum characteristics given its mass and power requirements. The pump down time required to reach a pressure of 50 Torr ranged from 60 minutes without the ballast to about 120 minutes with the gas ballast operational. The noise emission and the pump power were assessed in this paper as well.

Presented is a synopsis of ongoing research into the development of techniques and hardware required to produce useable quantities of astrobiology relevant biomass under controlled and repeatable laboratory conditions. This study has developed microbial habitats (referred to as digesters, due to their biomass production function) capable of sustaining microbial communities under low temperature, high salt, high sulfate, anaerobic conditions. This set of basic conditions is necessary to develop biomass material that is analog to the biomass that would be present in subsurface brine habitats on Mars or Europa, from the perspective of several critical biochemical properties.

The Vapor Phase Catalytic Ammonia Removal (VPCAR) system is being developed to recycle water for future NASA Exploration Missions. Testing was recently conducted on NASA's C-9B Reduced Gravity Aircraft to determine the microgravity performance of a key component of the VPCAR water recovery system. Six flights were conducted to evaluate the fluid dynamics of the Wiped-Film Rotating Disk (WFRD) distillation component of the VPCAR system in microgravity, focusing on the water delivery method. The experiments utilized a simplified system to study the process of forming a thin film on a disk similar to that in the evaporator section of VPCAR. Fluid issues are present with the current configuration, and the initial alternative configurations were only partial successful in microgravity operation. The underlying causes of these issues are understood, and new alternatives are being designed to rectify the problems.

Dewatering of wet waste during space exploration missions is important for crew safety as it stabilizes the waste. It may also be used to recover water and serve as a preconditioning step for waste compaction. A thermoelectric cooler (TEC)- driven lyophilizer is under development at NASA Ames Research Center for this purpose. It has three major components: (i) an evaporator section where water vapor sublimes from the frozen waste, (ii) a condenser section where this water vapor deposits as ice, and (iii) a TEC section which serves as a heat pump to transfer heat from the condenser to the evaporator. This paper analyses the heat and mass transfer processes in the lyophilizer in an effort to understand the ice formation behavior in the condenser. The analysis is supported by experimental observations of ice formation patterns in two different condenser units.

One of the largest single mass penalties required to support the human exploration of Mars is the surface habitat structural mass. Reducing the amount of structural material that must be launched from Earth to provide a habitat will reduce the cost of future missions. This paper describes the use of physical chemical technologies to produce high-density polyethylene for use as structural/construction materials from Mars atmospheric carbon dioxide. The formation of polyethylene from Mars carbon dioxide is based on the use of the Sabatier and modified Fischer Tropsch reactions. The system describe can be fully integrate with planned Mars in situ propellant production concepts.

Mixed liquid/solid wastes, including feces, water processor effluents, and food waste, can be lyophilized (freeze-dried) to recover the water they contain and stabilize the solids that remain. Our previous research has demonstrated the potential benefits of using thermoelectric heat pumps to build a lyophilizer for processing waste in microgravity. These results were used to build a working prototype suitable for ground-based human testing. This paper describes the prototype design and presents results of functional and performance tests.

This paper presents the results of a program to develop the next generation Vapor Phase Catalytic Ammonia Removal (VPCAR) system. VPCAR is a spacecraft water recycling system designed by NASA and constructed by Water Reuse Technology Inc. The technology has been identified by NASA to be the next generation water recycling system [1]. It is designed specifically for a Mars transit vehicle mission. This paper provides a description of the process and an evaluation of the performance of the new system. The equivalent system mass (ESM) is calculated and compared to the existing state-of-the art. A description of the contracting mechanism used to construct the new system is also provided.