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This project investigates methods to capture an astronaut's exhaled carbon dioxide (CO2) before it becomes diluted with the high volumetric oxygen flow present within a space suit. Typical expired breath contains CO2 partial pressures (pCO2) in the range of 20-35 mm Hg (.0226-.046 atm). This research investigates methods to capture the concentrated CO2 gas stream prior to its dilution with the low pCO2 ventilation flow. Specifically this research is looking at potential designs for a collection cup for use inside the space suit helmet. The collection cup concept is not the same as a breathing mask typical of that worn by firefighters and pilots. It is well known that most members of the astronaut corps view a mask as a serious deficiency in any space suit helmet design. Instead, the collection cup is a non-contact device that will be designed using a detailed Computational Fluid Dynamic (CFD) analysis of the ventilation flow environment within the helmet.

An EVA simulation with a medical contingency scenario was conducted in 2006 with the NASA Haughton-Mars and EVA Physiology System and Performance Projects, to develop medical contingency management and evacuation techniques for planetary surface exploration. A rescue/evacuation system to allow two rescuer astronauts to evacuate one incapacitated astronaut was evaluated. The rescue system was utilized effectively to extract an injured astronaut up a slope of15-25° and into a surface mobility rover for transport to a simulated habitat for advanced medical care. Further research is recommended to evaluate the effects of reduced gravity and to develop synergies with other surface systems for carrying out the contingency procedures.

Absorption cooling using a lithium chloride/water heat pump can enable lightweight and effective thermal control for Extravehicular Activity (EVA) suits without venting water to the environment. The key components in the system are an absorber/radiator that rejects heat to space and a flexible evaporation cooling garment that absorbs heat from the crew member, This paper describes progress in the design, development, and testing of the absorber/radiator and evaporation cooling garment. New design concepts and fabrication approaches will significantly reduce the mass of the absorber/radiator. We have also identified materials and demonstrated fabrication approaches for production of a flexible evaporation cooling garment, Data from tests of the system's modular components have validated the design models and allowed predictions of the size and weight of a complete system.

The NASA Shuttle Extravehicular Mobility Unit (EMU) uses a non-regenerable absorbent to remove CO2 from an astronaut's breathing loop. A savings in launch weight, storage volume and life cycle cost may be achieved by incorporating a regenerable CO2 removal system into the EMU. This paper will discuss regenerable CO2 sorbents and their impact on the life support system of an EMU. The systems evaluated will be judged on their technical maturity, impact to the EMU, and impacts to space station and shuttle operation

This paper discusses the Portable Life Support Subsystem (PLSS) packaging design work done by the NASA and Hamilton Sundstrand in support of the 3 future space missions; Lunar, Mars and zero-g. The goal is to seek ways to reduce the weight of PLSS packaging, and at the same time, develop a packaging scheme that would make PLSS technology changes less costly than the current packaging methods. This study builds on the results of NASA's in-house 1998 study, which resulted in the “Flex PLSS” concept. For this study the present EMU schematic (low earth orbit) was used so that the work team could concentrate on the packaging. The Flex PLSS packaging is required to: protect, connect, and hold the PLSS and its components together internally and externally while providing access to PLSS components internally for maintenance and for technology change without extensive redesign impact. The goal of this study was two fold: 1.

This paper details the analysis and design of the Temporary Sleep Station (TeSS) environmental control system for International Space Station (ISS). The TeSS will provide crewmembers with a private and personal space, to accommodate sleeping, donning and doffing of clothing, personal communication and performance of recreational activities. The need for privacy to accommodate these activities requires adequate ventilation inside the TeSS. This study considers whether temperature, carbon dioxide, and humidity remain within crew comfort and safety levels for various expected operating scenarios. Evaluation of these scenarios required the use and integration of various simulation codes. An approach was adapted for this study, whereby results from a particular code were integrated with other codes when necessary.

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.

Automatic thermal control (ATC) was investigated for implementation into a spacesuit to provide thermal neutrality to the astronaut through a range of activity levels. Two different control concepts were evaluated and compared for their ability to maintain subject thermal comfort. Six test subjects, who were involved in a series of three tests, walked on a treadmill following specific metabolic profiles while wearing the Mark III spacesuit in ambient environmental conditions. Results show that individual subject comfort was effectively provided by both algorithms over a broad range of metabolic activity. ATC appears to be highly effective in providing efficient, “hands-off” thermal regulation requiring minimal instrumentation. Final selection of an algorithm to be implemented in an advanced spacesuit system will require testing in dynamic thermal environments and consideration of technology for advancement in instrumentation and controller performance.

Approximately 50% of the water consumed by International Space Station crewmembers is water recovered from cabin humidity condensate. Condensing heat exchangers in the Russian Service Module (SM) and the United States On-Orbit Segment (USOS) are used to control cabin humidity levels. In the SM, humidity condensate flows directly from the heat exchanger to a water recovery system. In the USOS, a metal bellows tank located in the US Laboratory Module (LAB) collects and stores condensate, which is periodically off-loaded in about 20-liter batches to Contingency Water Containers (CWCs). The CWCs can then be transferred to the SM and connected to a Condensate Feed Unit that pumps the condensate from the CWCs into the water recovery system for processing. Samples of the condensate in the tank are collected during the off-loads and returned to Earth for analyses.

A reliable nutrient delivery system is essential for long-term cultivation of plants in space. At the Kennedy Space Center, a series of ground-based tests are being conducted to compare candidate plant nutrient delivery systems for space. To date, our major focus has concentrated on the Porous Tube Plant Nutrient Delivery System, the ASTROCULTURE™ System, and a zeoponic plant growth substrate. The merits of each system are based upon the performance of wheat supported over complete growth cycles. To varying degrees, each system supported wheat biomass production and showed distinct patterns for plant nutrient uptake and water use.

The Equivalent System Mass (ESM) metric developed by NASA describes and compares individual system impact on a closed system in terms of a single parameter, mass. The food system of a Mars mission may encompass a large percentage of total mission ESM, and decreasing this ESM would be beneficial. Yeast breads were made using three methods (hand & oven, bread machine, mixer with dough hook attachment & oven). Flat breads were made using four methods (hand & oven, hand & griddle, mixer with dough hook attachment & oven, mixer with dough hook attachment & griddle). Two formulations were used for each bread system (scratch ingredients, commercial mix). ESM was calculated for each of these scenarios. The objective of this study was to compare the ESM of yeast and flat bread production for a Martian surface outpost. Method (equipment) for both types of bread production was demonstrated to be the most significant influence of ESM when one equipment use was assumed.

As part of preparing for the Crew Exploration Vehicle (CEV), the National Aeronautics and Space Administration (NASA) worked on developing the requirements to manage the fire risk. The new CEV poses unique challenges to current fire protection systems. The size and configuration of the vehicle resembles the Apollo capsule instead of the current Space Shuttle or the International Space Station. The smaller free air volume and fully cold plated avionic bays of the CEV requires a different approach in fire protection than the ones currently utilized. The fire protection approach discussed in this paper incorporates historical lessons learned and fire detection and suppression system design philosophy spanning from Apollo to the International Space Station.

Scientists and engineers at NASA are currently developing flight instruments which will demonstrate oxygen production on the Moon and Mars. REGA will extract oxygen from the lunar regolith, measure implanted solar wind and indigenous gases, and monitor the lunar atmosphere. MIP will demonstrate oxygen production on Mars, along with key supporting technologies including filtration, atmospheric acquisition and compression, thermal management, solar cell performance, and dust removal.

Supply of oxygen (O2) and hydrogen (H2) by electrolyzing water in space will play an important role in meeting the National Aeronautics and Space Administration's (NASA's) needs and goals for future space missions. Both O2 and H2 are envisioned to be used in a variety of processes including crew life support, spacecraft propulsion, extravehicular activity, electrical power generation/storage as well as in scientific experiment and manufacturing processes. Life Systems, Inc., in conjunction with NASA, has been developing an alkaline-based Static Feed Electrolyzer (SFE). During the development of the water electrolysis technology over the past 23 years, an extensive engineering and scientific data base has been assembled.

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.

Sublimators have been used for heat rejection for a variety of space applications including the Apollo Lunar Module and the Extravehicular Mobility Unit (EMU). Sublimators are excellent candidates for heat rejection devices on future vehicles like the Crew Exploration Vehicle (CEV), the Lunar Surface Access Module (LSAM), and future spacesuits. One of the drawbacks of previous designs was sensitivity to contamination in the feedwater. Undissolved contaminants can be removed with filters, but dissolved contaminants would be left in the pores of the porous plates in which the feedwater freezes and sublimates. These contaminants build up and clog the relatively small pores (~3–6 μm), thereby blocking the flow of the feedwater, reducing the available area for freezing and sublimation, and degrading the performance of the sublimator. For the X-38 program, a new sublimator design was developed by NASA-JSC that is less sensitive to contaminants.

The Controlled Ecological Life Support System (CELSS) Emulator is under development at the NASA Johnson Space Center (JSC) with the purpose to investigate computer simulations of integrated CELSS operations involving humans, plants, and process machinery. This paper describes Version 1.0 of the CELSS Emulator that was initiated in 1988 on the JSC Multi Purpose Applications Console Test Bed as the simulation framework. The run module of the simulation system now contains a CELSS model called BLSS. The CELSS Emulator empowers us to generate model data sets, store libraries of results for further analysis, and also display plots of model variables as a function of time. The progress of the project is presented with sample test runs and simulation display pages.

A transient model of the Minimum Consumables Portable Life Support System (MPLSS) Advanced Space Suit design has been developed and implemented using MAT-LAB/Simulink. The purpose of the model is to help with sizing and evaluation of the MPLSS design and aid development of an automatic thermal comfort control strategy. The MPLSS model is described, a basic thermal comfort control strategy implemented, and the thermal characteristics of the MPLSS Advanced Space Suit are investigated.

Among the many firsts which will occur on STS-49, the maiden voyage of the Space Shuttle Endeavour, a Space Station Freedom (SSF) experiment entitled Assembly of Station by Extravehicular Activity (EVA) Methods (ASEM) promises to test the boundaries of EVA operational capabilities. Should the results be favorable, station and other major users of EVA stand to benefit from increased capabilities. Even the preparation for the ASEM experiment is serving as a pathfinder for complex SSF operations. This paper reviews the major tasks planned for ASEM and discusses the operational analogies investigators are attempting to draw between ASEM and SSF. How these findings may be applied to simplify station assembly and maintenance will also be discussed.

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.