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A trade study conducted in 2001 selected a rotary disk separator as the best candidate to meet the requirements for an International Space Station (ISS) Carbon Dioxide Reduction Assembly (CRA). The selected technology must provide micro-gravity gas/liquid separation and pump the liquid from 69 kPa (10 psia) at the gas/liquid interface to 124 kPa (18 psia) at the wastewater bus storage tank. The rotary disk concept, which has pedigree in other systems currently being built for installation on the ISS, failed to achieve the required pumping head within the allotted power. The separator discussed in this paper is a new design that was tested to determine compliance with performance requirements in the CRA. The drum separator and pump (DSP) design is similar to the Oxygen Generator Assembly (OGA) Rotary Separator Accumulator (RSA) in that it has a rotating assembly inside a stationary housing driven by a integral internal motor[1].

With a renewed focus on manned exploration, NASA is beginning to prepare for the challenges that lie ahead. Future manned missions will require a symbiosis of human and robotic infrastructure. As a step towards understanding the roles of humans and robots in future planetary exploration, NASA headquarters funded ILC Dover and the University of Maryland to perform research in the area of human and robotic interfaces. The research focused on development and testing of communication components, robotic command and control interfaces, electronic displays, EVA navigation software and hardware, and EVA lighting. The funded research was a 12-month effort culminating in a field test with NASA personnel.

When technologies are traded for incorporation into vehicle systems to support a specific mission scenario, they are often assessed in terms of “Technology Readiness Level” (TRL). TRL is based on three major categories of Core Technology Components, Ancillary Hardware and System Maturity, and Control and Control Integration. This paper describes the Technology Readiness Level assessment of the Carbon Dioxide Reduction Assembly (CRA) for use on the International Space Station. A team comprising of the NASA Johnson Space Center, Marshall Space Flight Center, Southwest Research Institute and Hamilton Sundstrand Space Systems International have been working on various aspects of the CRA to bring its TRL from 4/5 up to 6. This paper describes the work currently being done in the three major categories. Specific details are given on technology development of the Core Technology Components including the reactor, phase separator and CO2 compressor.

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.

NASA's Human Space Flight program depends heavily on spacewalks performed by pairs of suited human astronauts. These Extra-Vehicular Activities (EVAs) are severely restricted in both duration and scope by consumables and available manpower. An expanded multi-agent EVA team combining the information-gathering and problem-solving skills of human astronauts with the survivability and physical capabilities of highly dexterous space robots is proposed. A 1-g test featuring two NASA/DARPA Robonaut systems working side-by-side with a suited human subject is conducted to evaluate human-robot teaming strategies in the context of a simulated EVA assembly task based on the STS-61B ACCESS flight experiment.

Wheat is a candidate crop for the Advanced Life Support (ALS) system, and cereal grains and their products will be included on long-term space missions beyond low earth orbit. While the exact supply scenario has yet to be determined, some type of post-processing of these grains must occur if they are shipped as bulk ingredients or grown on site for use in foods. Understanding the requirements for processing grains in space is essential for incorporating the process into the ALS food system. The ESM metric developed by NASA describes and compares individual system impact on a closed system in terms of a single parameter, mass. The objective of this study was to compare the impact of grain mill type on the ESM of producing yeast and flat breads. Hard red spring wheat berries were ground using a Brabender Quadrumat Jr. or the Kitchen-Aid grain mill attachment (both are proposed post-harvest technologies for the ALS system) to produce white and whole wheat flour, respectively.

The International Space Station Carbon Dioxide Removal Assembly (CDRA) uses regenerable adsorption technology to remove carbon dioxide (CO2) from cabin air. CO2 product water vapor measurements from a CDRA test bed unit at the NASA Marshall Space Flight Center were made using a tunable infrared diode laser differential absorption spectrometer (TILDAS) provided by NASA Glenn Research Center. The TILDAS instrument exceeded all the test specifications, including sensitivity, dynamic range, time response, and unattended operation. During the CO2 desorption phase, water vapor concentrations as low as 5 ppmv were observed near the peak of CO2 evolution, rising to levels of ∼40 ppmv at the end of a cycle. Periods of high water concentration (>100 ppmv) were detected and shown to be caused by an experimental artifact.

Regenerative-type subsystems are being tested at JSC to provide atmosphere revitalization functions of oxygen supply and carbon dioxide (CO2) removal for a future Space Station. Oxygen is supplied by an electrolysis subsystem, developed by General Electric, Wilmington, Mass., which uses the product water from either the CO2 reduction subsystem or a water reclamation process. CO2 is removed and concentrated by an electrochemical process, developed by Life Systems, Inc., Cleveland, Ohio. The concentrated CO2 is reduced in a Sabatier process with the hydrogen from the electrolysis process to water and methane. This subsystem is developed by Hamilton Standard, Windsor Locks, Conn. These subsystems are being integrated into an atmosphere revitalization group. This paper describes the integrated test configuration and the initial checkout test. The feasibility and design compatibility of these subsystems integrated into an air revitalization system is discussed.

Hamilton Sundstrand Space Systems International, Inc. HSSSI) is under contract to NASA Marshall Space Flight Center (MSFC) to develop a Water Processor Assembly (WPA) and Oxygen Generation Assembly (OGA) for the International Space Station (ISS). The WPA produces potable quality water from humidity condensate, carbon dioxide reduction water, water obtained from fuel cells, reclaimed urine distillate, shower, handwash and oral hygiene waste waters. The Oxygen Generation Assembly (OGA) electrolyzes potable water from the Water Recover System (WRS) to provide gaseous oxygen to the Space Station module atmosphere. The OGA produces oxygen for metabolic consumption by crew and biological specimens. The OGA also replenishes oxygen lost by experiment ingestion, airlock depressurization, CO2 venting, and leakage. As a byproduct, gaseous hydrogen is generated. The hydrogen will be supplied at a specified pressure range to support future utilization.

The first ever Astronaut - Rover (ASRO) Interaction Field Test was conducted successfully on February 22-27, 1999, in Silver Lake, Mojave Desert, California in a representative surface terrain. This test was a joint effort between the NASA Ames Research Center, Moffett Field, California and the NASA Johnson Space Center, Houston, Texas to investigate the interaction between humans and robotic rovers for potential future planetary surface exploration. As prototype advanced planetary surface space suit and rover technologies are being developed for human planetary surface exploration, it is desirable to better understand the interaction and potential benefits of an Extravehiclar Activity (EVA) crewmember interacting with a robotic rover. This interaction between an EVA astronaut and a robotic rover is seen as complementary and can greatly enhance the productivity and safety of surface excursions.

Technologies for the recycling of water are a primary goal of NASA’s advanced life support programs. Biological processes have been identified as an attractive method for wastewater processing. A fundamental new bioreactor based on a traditional activated sludge process is demonstrated that treats hygiene wastewater using magnetic iron oxide particles agglomerated with microbial cells. In this bioreactor, microbes are suspended in magnetic flocs in a wastewater medium. Instead of a traditional gravity separator used in activated sludge operations, a magnetic separator removes the microbial flocs from the outlet stream. The reactor separation operates continuously, independent of gravitational influences. The reactor has been able to simultaneously remove 98% of high levels of both nitrogenous and organic carbon impurities from the wastewater as well as achieve acceptably low levels of total suspended solids.

Twenty-nine recycled water, eight stored (ground-supplied) water, and twenty-eight humidity condensate samples were collected on board the Mir Space Station during the Phase One Program (1995-1998). These samples were analyzed to determine potability of the recycled and ground-supplied water, to support the development of water quality monitoring procedures and standards, and to assist in the development of water reclamation hardware. This paper describes and summarizes the results of these analyses and lists the lessons learned from this project. Results show that the recycled water and stored water on board Mir, in general, met NASA, Russian Space Agency (RSA), and U.S. Environmental Protection Agency (EPA) standards.

Humidity condensate collected and processed in-flight is an important component of a space station drinking water supply. Water recovery systems in general are designed to handle finite concentrations of specific chemical components. Previous analyses of condensate derived from spacecraft and ground sources showed considerable variation in composition. Consequently, an investigation was conducted to collect condensate on the Shuttle while the vehicle was docked to Mir, and return the condensate to Earth for testing. This scenario emulates an early ISS configuration during a Shuttle docking, because the atmospheres intermix during docking and the condensate composition should reflect that. During the STS-89 and STS-91 flights, a total volume of 50 liters of condensate was collected and returned. Inorganic and organic chemical analyses were performed on aliquots of the fluid.

A Rotary Separator/Accumulator (RSA) has been developed to function as a phase separator and accumulator in the Oxygen Generator Assembly (OGA) in the microgravity environment of the International Space Station. The RSA design utilizes a fixed housing with rotating disks to create a centrifugal force field to separate hydrogen gas from water. The volume within the assembly is utilized to act as an accumulator for the OGA. During the development of the RSA, design refinements were made to meet the changing system operating requirements. Two proof of concept (POC) units and a “flight-like” development unit were fabricated and tested as system requirements evolved. Testing of the first POC unit demonstrated that a combined rotary separator and accumulator was feasible and showed areas where improvements could be made. The second POC unit incorporated a fifty percent volume increase to accommodate changing system requirements and geometry changes to help reduce power consumption.