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The International Space Station (ISS) requires advanced life support to continue its mission as a permanently-manned space laboratory and to reduce logistic resupply requirements as the Space Shuttle retires from service. Additionally, as humans reach to explore the moon and Mars, advanced vehicles and extraterrestrial bases will rely on life support systems that feature in-situ resource utilization to minimize launch weight and enhance mission capability. An obvious goal is the development of advanced systems that meet the requirements of both mission scenarios to reduce development costs by deploying common modules. A high pressure oxygen generating assembly (HPOGA) utilizing a high differential pressure (HDP) water electrolysis cell stack can provide a recharge capability for the high pressure oxygen storage tanks on-board the ISS independently of the Space Shuttle as well as offer a pathway for advanced life support equipment for future manned space exploration missions.

As the United States makes plans to return astronauts to the moon and eventually send them on to Mars, designing the most effective, efficient, and robust spacesuit life support system that will operate successfully in dusty environments is vital. Some knowledge has been acquired regarding the contaminants and level of infiltration that can be expected from lunar and Mars dust, however, risk mitigation strategies and filtration designs that will prevent contamination within a spacesuit life support system are yet undefined. A trade study was therefore initiated to identify and address these concerns, and to develop new requirements for the Constellation spacesuit element Portable Life Support System. This trade study investigated historical methods of controlling particulate contamination in spacesuits and space vehicles, and evaluated the possibility of using commercial technologies for this application. The trade study also examined potential filtration designs.

The design and evaluation of a Vacuum-Swing Adsorption (VSA) system to remove metabolic water and metabolic carbon dioxide from a spacecraft atmosphere is presented. The approach for Orion and Altair is a VSA system that removes not only 100 percent of the metabolic CO2 from the atmosphere, but also 100% of the metabolic water as well, a technology approach that has not been used in previous spacecraft life support systems. The design and development of an Orion Crew Exploration Vehicle Sorbent Based Atmosphere Revitalization system, including test articles, a facility test stand, and full-scale testing in late 2008 and early 2009 is discussed.

Water recovery is essential for long-duration space exploration transit and outpost missions. Primary stage wastewater recovery systems partially satisfy this need, and generate concentrated wastewater brines that are unusable without further processing. The Enhanced Brine Dewatering System (EBDS) is being developed to allow nearly complete recovery of water from Lunar Outpost wastewater brines. This paper describes the operation of the EBDS and discusses the development and testing of the major functional materials, components, and subsystems, including the wastewater brine ersatz formulations that are used in subsystem testing. The assembly progress of the EBDS full system prototype is also discussed, as well as plans for testing the prototype hardware.

In support of the Constellation Program, NASA conducted an analysis of crew clothing and laundry options. Disposable clothing is currently used in human space missions. However, the new mission duration, goals, launch penalties and habitat environments may lead to a different conclusion. Mass and volume for disposable clothing are major penalties in long-duration human missions. Equivalent System Mass (ESM) of crew clothing and hygiene towels was estimated at about 11% of total life support system ESM for a 4-crew, 10-year Lunar Outpost mission. Ways to lessen this penalty include: reduce clothing supply mass through using clothes made of advanced fabrics, reduce daily usage rate by extending wear duration and employing a laundry with reusable clothing. Lunar habitat atmosphere pressure and therefore oxygen volume percentage will be different from Space Station or Shuttle. Thus flammability of clothing must be revisited.

A life support system (LSS) is usually defined as a system that provides elements necessary for maintaining human life and health in the state required for performing a prescribed mission. The LSS, depending upon specific design requirements, will provide pressure, temperature, and composition of local atmosphere, food, and water. It may or may not collect, dispose, or reprocess wastes such as carbon dioxide, water vapor, urine, and feces. It can be seen from the preceding definition that LSS requirements may differ widely, depending on the mission specified, such as operation in Earth orbit or lunar mission. In all cases the time of operation is an important design factor. An LSS is sometimes briefly defined as a system providing atmospheric control and water, waste, and thermal management.

This standard covers the requirements for spherical, self-aligning, self-lubricating, bearings which are for use in the ambient temperature range of -65 to +160 °F (-54 to +71 °C) at high cyclic speeds 300 cpm (13 fpm) for liners with a thickness less than 0.015 inch. The scope of this standard is to provide a liner system qualification procedure for helicopter sliding bearings defined and controlled by source control drawings. Once a liner system is qualified, the source-controlled bearings are further tested under application conditions. Under Department of Defense (DoD) Policies and Procedures, any qualification requirements and associated Qualified Products List (QPLs) are mandatory for DoD contracts. Any materials relating to QPLs have not been adopted by SAE and are not part of this SAE technical document.

This document presents a catalog of safety sign text and artwork that can be used by any ready mixed concrete truck manufacturer to warn of common hazards.

Computational Fluid Dynamics airflow models for the Waste and Hygiene Compartment (WHC) in the U.S. Laboratory module and Node 3 were developed and examined. The International Space Station (ISS) currently provides human waste collection and hygiene facilities in the Russian Segment Service Module (SM) which supports a three person crew. An additional set of Russian hardware, known as the system, is planned for the United States Operational Segment (USOS) to support expansion of the crew to six persons. Integration of the Russian system into the USOS incorporates direct Environmental Control and Life Support System (ECLSS) interfaces to allow more autonomous operation. A preliminary design concept was used to create a geometry model to evaluate the air interaction with the module cabin at varied locations and performance of the avionics fan placed in WHC. The Russian and the privacy protection bump-outs (Kabin) were included into the present modeling.

During an ExtraVehicular Activity (EVA), both the heat generated by the astronaut's metabolism and that produced by the Portable Life Support System (PLSS) must be rejected to space. The heat sources include the heat of adsorption of metabolic CO2, the heat of condensation of water, the heat removed from the body by the liquid cooling garment, the load from the electrical components and incident radiation. Although the sublimator hardware to reject this load weighs only 1.58 kg (3.48 lbm), an additional 3.6 kg (8 lbm) of water are loaded into the unit, most of which is sublimated and lost to space, thus becoming the single largest expendable during an eight-hour EVA. Using a radiator to reject heat from the astronaut during an EVA can reduce the amount of expendable water consumed in the sublimator. Radiators have no moving parts and are thus simple and highly reliable. However, past freezable radiators have been too heavy.

This paper describes the Generic Modular Flow Schematic (GMFS) architecture capable of encompassing all functional elements of a physical/chemical life support system (LSS). The GMFS can be implemented to synthesize, model, analyze, and quantitatively compare many configurations of LSSs, from a simple, completely open-loop to a very complex closed-loop. The GMFS model is coded in ASPEN, a state-of-the art chemical process simulation program, to accurately compute the material, heat, and power flow quantities for every stream in each of the subsystem functional elements (SFEs) in the chosen configuration of a life support system. The GMFS approach integrates the various SFEs and subsystems in a hierarchical and modular fashion facilitating rapid substitutions and reconfiguration of a life support system. The comprehensive ASPEN material and energy balance output is transferred to a systems and technology assessment spreadsheet for rigorous system analysis and trade studies.

A model is being developed to quantitatively compare and select systems and technology option for defined missions envisioned in the National Aeronautics and Space Administration 's (NASA's) Space Exploration Initiative. This model consists of a modular, top-down hierarchical break-down of the life support system (LSS) into subsystems, and further break-down of subsystems, into functional elements representing individual processing technologies. A series of papers titled Human Life Support During Interplanetary Travel and Domicile has been planned to describe the technique and results. Part I, presented at the 19th ICES Conference, describe the system approach. Part II, presented at this conference, describe Part III, this paper, describes results of a system trade study for a Mars Expedition mission comparing open and closed loop systems.

A model is being developed to quantitatively compare and select systems and technology options for defined missions envisioned in the National Aeronautics and Space Administration's (NASA's) Space Exploration Initiative. It consists of a modular, top-down hierarchical break-down of the life support system (LSS) into subsystems, and further break-down of subsystems into functional elements representing individual processing technologies. A series of papers titled “Human Life Support During Interplanetary Travel and Domicile” was planned to describe the technique and results. Part I, presented at the 19th ICES Conference, described the system approach. Parts II, III, and IV are presented at this conference. Part II describes the modeling technique. Part III describes results of a system trade study for a Mars Expedition Mission comparing open and closed loop systems.

The generation of submarines beyond Seawolf will require more sophisticated ship systems as the quest for absolute quiet, total reliability and unattended operation continues. The Submarine Advanced Integrated Life Support System (SAILS) is the result of analyses which first define, and then implement, technology development. SAILS is organized around the projected capability of and SPE® electrochemical cell which simultaneously coverts carbon dioxide to liquid organics and water to pure oxygen without the presence of gaseous hydrogen. Other technologies employed in the SAILS system include an SPE electrochemical absorbent Regeneration/CO2 Compression Subsystem, a liquid CO2 Absorber, an Organic Water Separator and a Catalytic Contaminant removal system. This paper presents an overview of the existing submarine life support equipment and describes the payoffs offered to a submarine by implementing SAILS technologies into a next generation life support system.

Conceptual designs for initial, intermediate, and advanced lunar base life support systems (LSS) are under development at JSC. The initial air revitalization, water recovery, and waste management subsystems are based on space station technologies. The intermediate system expands on the initial capabilities; for example, the initial waste management subsystem allows only for compacting and storing solid waste, while the intermediate waste management subsystem includes measures for recovering useful substances from the waste. The advanced system includes biological waste treatment and higher plants to be used for air revitalization and water processing. This paper describes the three systems and discusses the basis for selecting individual processes. System-level mass balances are used to illustrate the interaction of the air, water, and waste loops. The effect of introducing different waste treatment processes into the initial LSS is examined.

Within the total submarine system, the life support system assumes a position which is equal in importance to the propulsion, weapons, and navigation systems. Without an efficient and reliable life support system, the other ship systems and the personnel who operate and maintain them cannot function to their full capabilities during extended periods of submergence. As a result of new requirements, new technology, and poor fleet performance, the Naval Sea Systems Command (NAVSEA) has developed new life support equipment that improves reliability, safety, operability, and capability. NAVSEA has developed, prototyped, successfully tested, and placed into production a new atmosphere analyzer and a new oxygen generator. This paper will address the US Navy's life support system design parameters, an overview of existing life support system, reasons for change, concept development and testing of new equipment, transition to production, and production and fleet implementation.

Recent NASA-funded studies of Allied-Signal metal-oxide-based absorbents demonstrated that these absorbents offer a unique capability to remove both metabolic carbon dioxide (CO2) and water (H2O) vapor from breathing air; previously, metal oxides were considered only for the removal of CO2. The concurrent removal of CO2 and H2O vapor can simplify the astronaut portable life support system (PLSS) by combining the CO2 and humidity control functions into one component. A further benefit is that the removal processes are reversible, permitting a regenerative component. Thus, a metal oxide absorbent offers many advantages over the current system, which is nonregenerative and uses separate processes for CO2 and H2O vapor removal. These advantages include lower complexity, lower maintenance, and longer life. The use of metal oxide absorbents for removal of both CO2 and H2O vapor in the PLSS is the focus of an ongoing NASA program.

A thermal model has been developed to evaluate, from a thermal and performance standpoint, a preliminary design of a Neutral Buoyancy Cryogenic fluid delivery System (NBCS). The NBCS is an important component of a Neutral Buoyancy Portable Life Support System (NBPLSS) to be used by suited astronauts in underwater training for extravehicular activity (EVA) at Johnson Space Center, Houston, Texas. The Systems Improved Numerical Differencing Analyzer-1985 Fluid Integrator (SINDA'85/FLUINT) program is used to model the NBCS. The modeling decisions are described, based on details of tank construction and material selection, and include the breakdown of the model components into nodes and conductors. The modeling of positional transients which result from moving internal components are presented, including the control of cycling artifacts. The convection and boiling considerations of three tank fluids (cryogenic fluid, 250 psi N2/O2 gas, and water) are presented.

The various configurations being considered for Space Station Freedom have resulted in a moving target for tomorrow's demand for EVA and the requirements that will be imposed on the Extravehicular Mobility Unit (EMU). The Shuttle EMU is baselined to perform the assembly and operational activities of station and is currently undergoing the necessary incremental re-certification. This paper presents the evolution of an EMU from two perspectives. First, evolution is discussed within the context of continuously improving the life support system and the space suit assembly from the Mercury Program to NASA's current flight EMU. This includes a status of the on-going enhancements and a discussion on the merits of additional improvements. The second perspective describes evolution for future programs involving significant differences in mission requirements and environments.

A system performance study on a portable life support system being developed for use in the Weightless Environment Training Facility (WETF) and the Neutral Buoyancy Laboratory (NBL) has been completed. The Neutral Buoyancy Portable Life Support System (NBPLSS) will provide life support to suited astronauts training for extravehicular activity (EVA) under water without the use of umbilicals. The basic configuration is characterized by the use of medium pressure (200 - 300 psi) cryogen (liquid nitrogen/oxygen mixture) which provides cooling within the Extravehicular Mobility Unit (EMU), the momentum which enables flow in the vent loop, and oxygen for breathing. NBPLSS performance was analyzed by using a modified Metabolic Man program to compare competing configurations. Maximum sustainable steady state metabolic rates and transient performance based on a typical WETF metabolic rate profile were determined and compared.