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The U.S. Laboratory (USL) module on Space Station will house a biological research facility for multidisciplinary research using living plant and animal specimens. The science community requires that the specimen environment remain biologically isolated from the rest of the Station environment. Environmentally closed chambers isolate the specimen habitats, but specimens must be removed from these chambers during research procedures as well as while the chambers are being cleaned. An enclosed, sealed Life Science Glovebox (LSG) is the only locale in the USL where specimens can be accessed by crew members. This paper discusses the key science, engineering and operational considerations and constraints involving the LSG, such as bioisolation, accessibility, and functional versatility. Existing glovebox technology is reviewed and the potential for adding automation, robotics, and telecommunications to the LSG is discussed.

Key design drivers of the Life Support System (LSS) of advanced manned space missions are duration, distance from Earth and cost. All drive the LSS design towards the elimination of expendables and resupply requirements (from Earth). Two approaches can be taken towards achieving this goal: (1) increasing the LSS closure - via the use of regenerative technologies and (2) utilization of local resources - via the use of LSS specific technologies and/or the use of products and by-products from other systems and activities (e.g., propulsion system and manufacturing processes). Local resource utilization will be required to completely eliminate resupply requirements from Earth (e.g., to make up atmospheric losses as a result of leakage, airlock uses, etc.). Also, in some instances, it may be advantageous to utilize local resources instead of regenerative technologies. This paper provides an introduction and overview to local resource utilization related to the LSS of advanced missions.

Habitability and environmental control life support systems (ECLSS) for interplanetary vehicles and bases must advance toward closing the environmental control loop and the driving issues are recycling waste and eliminating trash. Hybrid systems combining physicochemical and ecological processes are the next logical step and may be the key to developing a nearly closed ECLSS for one to three year duration missions. Habitability subsystems must also contribute to minimizing or eliminating trash/waste products. Current technology approaches closed-loop status in the oxygen and water reclamation areas, but is lacking in systems producing solid waste and trash.

The operational environment for life sciences on the Space Station will incorporate telescience, a new set of operational modes for conducting science and operations remotely. This paperpresents payload functional requirements for Space Station Life Sciences habitat monitoring and control and describes telescience concepts and technologies which meet these requirements. Special considerations for designing sensors and effectors to accommodate future evolutions in technology are discussed.

The piloted Mars sprint scenario of NASA's “Humans to Mars” initiative involves round-trip “sprints” with a 2-week exploration of the Martian surface. This paper investigates the bio-isolation dynamics of plants and humans in a piloted Mars sprint. To simulate a life support system for a crew of six, a transient, thermal-network model is used. Two crops, lettuce and winged beans, are chosen for a cabin greenhouse. The crew cabin and the greenhouse are physically separated but dynamically interfaced with mass and energy flows. The plants provide the bio-regenerative portion of air, water, food, and waste cycles. The percentage of contribution by bio-regeneration to air revitalization, water reclamation, wet food supply, and waste processing functions are 9, 29, 22, and 50 percent, respectively.

This paper describes a prototype expert system being developed for maintaining autonomous operation of a Mars oxygen production system. System and sensor failure modes and their corresponding symptoms are identified. For a set of operating condition definitions, a knowledge-based diagnostic algorithm is developed to handle several housekeeping functions. These functions include self-health checkout; an emergency shutdown program; failure detection and isolation and active control commands. Finally, a computer simulation using BASIC language has demonstrated the feasibility of the expert system and verifies its rule-based diagnosis and decision making algorithms.

Astronaut missions to Mars call for voyages remote from Earth on unprecedented scales of time and distance. Mission success will center around the management of certain critical compounds containing the atoms H and O. This generalization is true for both the life support systems and propulsion systems (for early missions at least). Mission lengths of one to three years allow virtually no possibility of timely rescue. Nonetheless, even with one or more major system failures, contingency mode H/O utilization can provide the key to survival on the road back to Earth.

A baseline ECLS system for a lunar base manned intermittently by four crewpersons and later permanently occupied by eight crewpersons has been designed. A summary of physical characteristics for the intermittently manned ECLS system includes a launch weight of 10,590 lb, launch volume of 955 ft3, 90-day resupply weight of 5972 lb, 90-day resupply volume of 346 ft3, and a power requirement of 10.494 kW. Evolution into a continuously manned base generates the following incremental requirements: launch weight of 19,935 lb, launch volume of 1178 ft3, 90-day resupply of 4928 lb, 90-day resupply of 403 ft3, and power requirement of 10.695 kW. A supplementary study assessed tankage requirements, penalties incurred by adding subsystem redundancy and by pressurizing large surface structures, and difficulties imposed by intermittent occupancy. Alternate concepts using lunar derived oxygen, the gravity field as a design aid, and a city utility type ECLS system offer potential advantages.

Four regenerative ECLSS assemblies, built by Hamilton Standard, have been undergoing testing at NASA's Marshall Space Flight Center (MSFC) during the past year. This paper describes each pre-prototype assembly and presents test objectives and data accumulated over the period of July 1987 through June 1988. The primary test activity was NASA's Integrated Systems Metabolic Control Test conducted in MSFC's Core Module Integration Facility (CMIF). This paper describes the operation and performance of the TIMES urine reclamation assembly and the Sabatier CO2 reduction assembly in that test. The other two technologies covered are the bench testing of the SAWD CO2 removal assembly and the integrated propulsion testing of the Static Feed SPE® O2 generation assembly.

This paper presents the conceptual design of a life support system sustaining a crew of six in a piloted Mars sprint. The requirements and constraints of the system are discussed along with its baseline performance parameters. An integrated operation is achieved with air, water, and waste processing and supplemental food production. The design philosophy includes maximized reliability considerations, regenerative operations, reduced expendables, and fresh harvest capability. The life support system performance will be described with characteristics of the associated physical-chemical subsystems and a greenhouse. MANNED MISSIONS TO THE PLANET MARS are included in the present NASA plans for the first decade of the next century [1]*. The first step of human exploration and eventual settlement on Mars will probably be a series of fast missions (“sprints”), with a duration of just over one year, round trip [2].

The new generation of high-pressure hard space suits allows designers to employ passive means of thermal control of the suit, with a reflective coating. An effort is underway to determine the coating material of choice for the AX-5 prototype hard space suit. Samples of 6061 aluminum have been coated with one of 10 selected metal coatings, and subjected to corrosion, abrasion and thermal testing. Changes in reflectance after exposure are documented. Plated gold exhibited minimal degradation of optical properties. A computer model is used in evaluating coating thermal performance in the EVA environment. The model is verified with an experiment designed to measure the heat transfer characteristics of coated space suit parts in a thermal vacuum chamber. Details of this experiment are presented here.

This paper describes the major lunar resources that would be tapped in developing a Controlled Ecological Life Support System (CELSS) greenhouse for a manned lunar base. The use of the moon's gravitational field, natural sunlight, and mineral resources from the lunar surface are discussed. Lunar soil processing technologies with CELSS relevance, and their contributions to greenhouse development are presented.

The Space Station Extravehicular Activity (EVA) Test Bed program at the Johnson Space Center (JSC) is addressed. A summary of the current testing activities are discussed as well as the test bed goals and future plans to support the Space Station Extravehicular Activity System (EVAS) development program.

Regenerable carbon dioxide (CO2) and moisture removal techniques that reduce expendables and logistics requirements are needed to sustain people undertaking extravehicular activities for the Space Station. Life Systems, working with National Aeronautics and Space Administration has been developing and investigating the ways to advance the Electrochemically Regenerable CO2 and Moisture Absorption (ERCA) technology to replace the nonregenerable solid lithium hydroxide absorber for the advanced Portable Life Support System (PLSS). During extravehicular activities the ERCA technique uses a mechanism involving gas diffusion and absorption into liquid absorbent for the removal and storage of the metabolically produced CO2 and moisture. Following the extravehicular activities, the expended absorbent is regenerated on-board the Space Station by an electrochemical method which restores the CO2 and moisture absorption capabilities of the absorbent.

The Extravehicular Activity (EVA) operations for Space Station (SS) require that a regenerable carbon dioxide (CO2) absorber be developed for the manned Extravehicular Mobility Unit (EMU). A concept which employs a solid amine resin to remove metabolic CCL and water vapor from the breathing air within the space suit is being developed by the Hamilton Standard Division of United Technologies Corporation under Contract NAS 9-17480 with the National Aeronautics and Space Administration (NASA) Johnson Space Center (JSC). The solid amine is packed within a water cooled metal foam matrix heat exchanger to remove the exothermic heat of chemical reaction. After completion of the EVA mission, the amine is regenerated on board the Space Station within the heat exchanger using a combination of heat and vacuum. This paper describes the concept design features, operational considerations and test results during simulated laboratory conditions.

This paper outlines the selection, design, and testing of a prototype nonventing regenerable astronaut cooling system for Extravehicular Activity (EVA) space suit applications, for mission durations of four hours or greater. The selected system consists of the following key elements: a radiator assembly which serves as the exterior shell of the portable life support subsystem (PLSS) backpack; a layer of phase change thermal storage material, n-hexadecane paraffin, which acts as a regenerable thermal capacitor; a thermoelectric heat pump; and an automatic temperature control system. The capability for regeneration of thermal storage capacity with and without the aid of electric power is provided.

Future space missions will feature extensive EVA operations. In order to avoid the expendables and logistics penalties associated with recharging the EMU's oxygen supply bottles on the ground, a High Pressure Oxygen Recharge System (HPORS), is being developed for use aboard the Space Station. The HPORS will be an electrolysis system capable of providing oxygen at up to 6000 psia without the use of a mechanical compressor, using only the facilities that will be available on board the Space Station (electrical, nitrogen and water). The Hamilton Standard HPORS will be based on a solid polymer electrolyte system which has already demonstrated thousands of hours of performance at 3000 psia in an oxygen generating plant for military applications. The program includes testing of various water feed modes, operating temperatures and current densities in order to optimize the system size, weight and power consumption.

Performing checkout, servicing, and maintenance of an Extravehicular Activity System (EVAS) on board the Space Station presents several unique challenges. This paper reviews the progress that has been made in the initial effort to define, design, and develop a system that will perform this function. The need for rapid “turnaround” of the EVA capability has not been a significant requirement for the Shuttle program where EVA is only an occasional occurrence (two missions per year). Because of this in frequency and because reservicing is performed on the ground rather than on orbit, the current expenditure of approximately 3,000 manhours to process each Shuttle Extravehicular Mobility Unit (EMU) is acceptable. However, current estimates on the EVA frequency required to support Space Station operations is projected at twice weekly.

The space-erectable radiator system (SERS) is being developed by NASA-JSC to provide a long-life, highly reliable waste heat rejection capability for Space Station and similar large space systems. In general, the SERS features modular, high-capacity radiator panels that can be installed and replaced on-orbit, as needed. Each panel interfaces with the central heat transport loop through a dry contact heat exchanger attachment. The Grumman prototype SERS is based upon a low-risk extension of proven monogroove heat pipe technology for the radiator element and a simple “whiffletree” mechanical clamping mechanism for achieving the required contact pressure at the dry attachment interface. The SERS ground test article that has been built consists of eight radiator panels, each 1 ft wide by 48 ft long, and eight separate whiffletree clamps that engage a 2 ft2 contact area.

The anodic coatings developed by anodizing specific aluminum alloys show considerable promise as long-life/durable radiator coatings. These coatings, formed by the sulfuric acid anodizing process, were the best performers of a variety of candidate coatings subjected to ultraviolet radiation and temperature-cycling tests.