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The NASA-developed space-suit configurations for Project Mercury and the Gemini Program originated from high-altitude-aircraft full-pressure-suit technology. These early suits lacked sophisticated mobility systems, since the suit served primarily as a backup system against the loss of cabin pressure and required limited pressurized intravehicular mobility functions for a return capability. Beginning with the Gemini Program, enhanced mobility systems were developed to enable crewmembers to perform useful tasks outside the spacecraft. The zero-prebreathe Hark III (ZPS Mk III) model of a higher operating pressure (57.2 kN/m2 (8.3 psi)) space-suit assembly represents a significant phase in the evolutionary development of a candidate operational space-suit system for the Space Station Program. The various design features and planned testing activities for the ZPS Mk III 57.2-kN/m2 (8.3 psi) space suit are described and identified.

The Spacelab Life Sciences missions are intended to support Life Sciences experiments. The Spacelab Life Sciences 1 (SLS-1) mission originated with a call to the scientific community for experiments in 1978. Accepted experiments involved humans, primates, rodents, amphibians, and plants. The original payload configuration has been reduced to include human, passive rodent, and basic biology experiments and engineering evaluations. Human experiments will address effects of micro-gravity on various physiological parameters during and postflight. Investigations with nonhuman subjects will study microgravity effects on the cardiopulmonary, cardiovascular, and musculoskeletal systems, on the regulation of blood volume and erythropoiesis, and on calcium metabolism and gravity receptors. SLS-1 will serve as a stepping stone in establishing capabilities for flying nonhuman subjects and performing in-flight manipulations on these subjects without jeopardizing the crew environment.

During the early period of space-suit glove development, heavy reliance was placed on military high-altitude-aircraft full-pressure-suit technology. This status was typical of Project Mercury and early in the Gemini Program. Longer space flights and the advent of extravehicular (EV) operations required drastic improvements in the areas of comfort and mobility, and the incorporation of an EV-hazards protective coverlayer. The current advanced glove designs represent a series of evolutionary engineering efforts aimed at systematically improving higher operating pressure EV glove performance capabilities. The key glove performance issue becomes one of finding the proper balance between the basic protective requirements (i.e., EV environmental hazards) and the performance requirements of the functional glove assembly. Glove design complexity increases with the differential pressure between the glove and the vacuum of space and with the EV activity mobility task requirements.

The Spacelab Life Sciences 2 mission (SLS-2) is the second in a planned series of dedicated Life Sciences missions utilizing the European Space Agency-provided Spacelab module. The mission, tentatively scheduled for a mid-1992 launch, will comprise a total of eighteen experiments encompassing both human and animal research. Eight of the eighteen experiments will involve animal life sciences research and will be managed by the Space Life Sciences Payloads Office (SLSPO) at NASA's Ames Research Center (ARC). The ARC payload complement of eight experiments will include six which use rodents and two which use primates (squirrel monkeys). SLS-2 provides an opportunity for even more extensive investigations into the effects of weightlessness upon the anatomy and physiology of rodent and primate systems.

One of the major problems faced in Extravehicular Activity (EVA) glove development has been the absence of concise and reliable methods to measure the effects of EVA gloves on human-hand capabilities. This paper describes the development of a standardized set of tests designed to assess EVA-gloved hand capabilities in six measurement domains: Range of Motion, Strength, Tactile Perception, Dexterity, Fatigue, and Comfort. Based upon an assessment of general human-hand functioning and EVA task requirements several tests within each measurement domain were developed to provide a comprehensive evaluation. All tests were designed to be conducted in a glove box with the barehand as a baseline and the EVA glove at operating pressure.

Reverse osmosis was investigated for purifying Space Station washwater. Experiments were performed on membrane coupons and spiral-wound membrane modules. The membranes were operated at pasteurization temperature (74°C) to prevent microbial growth. Effects of temperature and various surfactants were studied. The permeate quality was determined by analyzing the composition of the water for individual ions, surfactants, and organics. The membrane of choice has acceptable separation performance. An activated carbon post-filter removed residual organics such as surfactants and urea from the membrane permeate. A preprototype washwater reclamation unit was built and operated continuously for 12.5 days, and approximately 2200 gallons of water were processed; this quantity of water would meet the requirements of an eight-person crew for 41 days. The unit operated according to design and processed water meeting the NASA hygiene water processing (separation) standards.

The routine extravehicular activity (EVA) anticipated from the United States Space Station dictates that productivity be maximized for astronaut accessibility to information during the EVA, Ideally for Space Station EVA, this requires a “hands-free” operation, especially for intensive EVA scenarios such as satellite servicing and emergency or contingent operations. This hands-free access to information will be provided to the crewmember via a voice recognition & control system and a helmet-mounted projection display in the Space Station Extravehicular Mobility Unit (EMU). To demonstrate the capabilities of the combined system, a simulation program has been created which addreses the human factors required to effectively provide the crewmember with productive information during an EVA.

A greater number of manned extravehicular activities (EVAs) are anticipated for the United States Space Station compared to the few experienced on Space Shuttle missions. This requires the design of a new generation extravehicular mobility unit (EMU). Limitations inherent in the current EMU power supply--zinc silver-oxide batteries--include dry shelf-life, active wet-life, cycle-life, and recharge time, thus making its usage impractical for the Space Station. An alternative solution, a fuel cell energy storage system (FCESS), is being explored by Ergenics Power Systems, Inc. (EPSI), Wyckoff, N.J., with funding from NASA/Johnson Space Center. The ion-exchange membrane (IEM) fuel cell under consideration utilizes hydrogen stored as a metal hydride. EPSI has demonstrated experimentally that the fuel cell/hydride technology pair should be a primary candidate EMU power supply for its high volumetric/energy density and cycle life, quick recharge, durability, EMU integration, and safety.

The inherent simplicity und reliability of air evaporation urine processing have been demonstrated in a number of system tests over the past 25 years. Although no flight-rated air evaporation systems have been built, the air evaporation approach has by far logged the most time in man-rated tests. Air evaporation offers additional inherent advantages such as near total water recovery and insentivity to intermittent operation. The principal disadvantage of simple-cycle air evaporator units built heretofore is their high energy requirement. An enhanced air evaporation configuration has been analyzed that incorporates a recuperator and an R12 heat pump for energy recovery. Performance is increased sufficiently to be competitive with alternative more complex processes. A parametric performance study was conducted in terms of major component efficiencies. Components were sized for an eight-man processing unit.

The Orbital Maneuvering Vehicle (OMV) systems' performance coupled with its canti-levered payload capability provides an excellent orbital test bed for short- and intermediate-duration life support subsystem and subscale system experimental investigations. As an experiment carrier or support vehicle, the OMV can remove the experiment or engineering test bed from the National Space Transportation System (NSTS) or Space Station environmental influences. This paper explores both the primary OMV capability to support short-term experiments as well as intermediate-duration evaluations of life support system.

Thermal and environmental control of spacecraft and astronauts during extravehicular activity requires the transfer of heat between various thermal sources and sinks. Solid/vapor heat pump technology utilizing a condensing/evaporating refrigerant holds considerable promise for space applications due to the variable temperature and variable load capabilities of these devices. In addition, solid/vapor adsorption systems involve no moving parts, may utilize non-toxic and non-flammable solid adsorbents and refrigerants, and are lightweight. This paper describes the fundamental operating characteristics of solid/vapor adsorption technology. The effects of (1) the choice of the specific refrigerant/adsorbent pair, (2) the thermal sink and source temperatures, and (3) the heat transfer characteristics of the adsorption beds on the performance of the system are described.

This paper outlines the current status of the Space Station Environmental Control and Life Support System (ECLSS). The seven subsystem groups which comprise the ECLSS are identified and their functional descriptions are provided. The impact that the nominal and safe haven operating requirements have on the physical distribution, sizing, and number of ECLSS subsystems is described. The role that the major ECLSS interfaces with other Space Station systems and elements play in the ECLSS design is described.

The use of thermodynamic power cycles in space results in much higher conversion efficiencies than the traditional solar cell or thermoelectric couple. This has many beneficial consequences in both solar and nuclear applications. The 20% to 30% cycle efficiency reduces the solar energy collection area significantly, thereby reducing size, weight and drag for low earth orbit missions such as the Space Station. For nuclear fueled systems, the 4 to 5 fold increase in conversion efficiency over thermoelectrics reduces the amount of fuel needed, thereby reducing weight, size, cost and hazard. Two competing dynamic cycles, the Organic Rankine Cycle (ORC) and the Closed Bray ton Cycle (CBC), are being developed by NASA LeRC for solar dynamic systems on the Space Station and by DOE for the U.S. Air Force. For each application (solar or nuclear), the basic cycles are similar. The major variable is power level. The solar dynamic systems being considered are in the 20 to 40 KWe range.

For long term manned space missions, considerable quantities of materials for life support will be consumed. The ability to recycle such materials, particularly water, offers significant benefits in reducing the costs and logistical difficulties of resupply from earth. The application of supercritical water oxidation (SCWO) waste treatment and water recycling technology to the problem of waste disposal in space is being developed for NASA by MODAR, Inc. As inorganic constituents present in the waste are not soluble in supercritical water, they must be removed from the organic-free, supercritical fluid reactor effluent. Experimental results are presented on the separation of solids from the process stream by removal mechanisms which could be suitable for a microgravity environment. The solid properties and their influence on the design of several oxidation reactor/solids separator configurations under study are presented.

Future large spacecraft such as the Space Station will have high power dissipations and long heat transport distances. The combination of these two requirements dictate the need for a new heat transport technology. Boeing Aerospace developed an ammonia thermal bus (ATB) concept using two-phase ammonia as the working fluid. Instrumentation and control systems were used to verify system performance, protect personnel and equipment safety, and run the system. The ATB was robust; thus operating procedures were simple and fault tolerant. Test results demonstrated a maximum heat load of 22 kW, a controllable turndown ratio of 44:1, and the ability to control setpoint temperatures within the range of 30 to 90°F. This paper describes the ammonia thermal bus (ATB), test instrumentation and control, procedures for operating the ATB, and test results.

Future long term space flights will require on-board water/waste recycling in a partially or fully enclosed life support system. Oxidation of the products of human metabolism in supercritical water has been shown to be an efficient way to accomplish this recycling. Fundamental understanding of the oxidation of compounds in supercritical water is essential for the design, development and operation of a supercritical water oxidation unit. Oxidation studies of methane up to 700°C have recently been completed and are presented in this paper. Experiments are currently being performed to determine reaction kinetic parameters for the oxidation of other model compounds in supercritical water such as ammonia, methanol, acetaldehyde, and mixtures of ammonia and co-oxidants. Theoretical studies of fundamental kinetics and mechanistic pathways in supercritical water oxidation are discussed.

Due to the need to reduce the power requirements and thus the weight of large space-based neutral particle beam (NPB) space platforms, current systems studies propose that these NPB accelerators be maintained at cryogenic temperature levels. As such, the ground test articles that will be used to develop many of the technological advancements necessary prior to engineering development of an operational NPB space platform, will also address the issues of operating cryogenically. In support of a number of these programs, a cryogenic cooling test of a typical accelerator component was performed. This paper discusses the various modes of cryogenic cooling proposed (two-phase convective boiling and single-phase supercritical convection), the advantages and disadvantages of each, gives details of the test, and compares the test results to analytical predictions.

Space Station nodes packaging analyses are presented relative to moving environmental control and life support system (ECLSS) equipment from the habitability (HAB) module to node 4 in order to provide more living space and privacy for the crew, remove inherently noisy equipment from the crew quarter, retain crew waste collection and processing equipment in one location, and keep objectionable odor away from the living quarters. In addition, options for moving external electronic equipment from the Space Station truss to pressurized node 3 were evaluated in order to reduce the crew extravehicular activity (EVA) time required to install and maintain the equipment. Node size considered in this analysis is 3.66 m (12 ft) in diameter and 5.38 m (17.67 ft) long. The analysis shows that significant external electronic equipment could be relocated from the Space Station truss structure to node 3 and non-life critical ECLSS HAB module equipment could be moved to node 4.

Thermal climate in automobiles, buses, trucks arid indoors has been evaluated using a newly developed thermal manikin. Heatman. Test results indicate a noticeable difference among cars. In a cold environment, the general problem is distribution between wind screen and lower part and asymmetry for right and left sides of individuals. In a warm climate, air is often distributed unevenly, thus resulting in discomfort. The results are shown as heat flow (W/m2) from 36 areas of the body or as equivalent (sensed) temperatures. The PMV-PPD comfort index is also derived from these measurements. Measurement and assessment of thermal climate using a thermal manikin will make it possible to evaluate the best solution for thermal control. It can also be used to measure clothing and chair insulation.

This paper describes the development of a membrane-based dehumidification process for space-based applications, such as spacecraft cabins and extra-vehicular-activity (EVA) space suits. Results presented are from 1) screening tests conducted to determine the efficacy of various membranes to separate water vapor from air, and 2) parametric and long-term tests of membranes operated at conditions that simulate the range of environmental conditions (e.g., temperature and relative humidity [RH]) expected in the planned space station. Also included in this paper is a discussion of preliminary designs of membrane-based dehumidification processes for the space station and EVA space suits. These designs result in compact and energy-efficient systems that offer significant advantages over conventional dehumidification processes.