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FLUIDNET is a new computer program for preliminary sizing of fluid loop networks used in space thermal control systems. The program was developed at AEROSPATIALE'S Cannes facility, under a contract of the french space agency (CNES), on joint CNES/AEROSPATIALE funding. FLUIDNET is an interactive application, whose main features are portability, easy implementation, speed and flexibility. It is fully complementary with design tools like SINDA and ESATAN fluid loop analysis extensions (FLUINT and FHTS). The current version is applied to thermal and hydraulic analysis of single phase fluid loops in steady state. Further version is already in development with increased performances, in particular analysis of transient phases. For first applications, this program is essentially devoted to HERMES thermal control subsystem design.

This paper discusses designs for outfitting NASA Space Station Resource Nodes. It briefly summarizes the evolution of Resource Nodes to their current configuration and discusses functional and design requirements driving their overall configuration and internal outfitting. Significant features of Resource Node internal architecture, distributed system packaging, crew accommodations, and utility distribution are described. This approach to Resource Node outfitting meets current requirements for crew operations, on-orbit maintainability, and growth for the projected 30 year life of the Space Station.

This paper describes the development of a microcomputer based control system for a heat pump containing an electrical variable speed compressor drive and a motorized expansion valve. It is designed to operate under very much varying load conditions with minimum power consumption. Difficulties that were encountered during engineering tests could finally be overcome by a relatively simple, practical regulator configuration. It operates near optimum efficiency by regulating a certain temperature difference in the evaporator. Experimental data on operating characteristics and performance are included in the paper.

A baseline design has been selected for the Space Station Habitat (HAB) element. The HAB provides the primary living space to support man's permanent presence in space. The HAB element is designed to provide an environment that maximizes safety and human productivity. This paper outlines some of the current design features including the common core elements and the man-systems hardware. The HAB is arranged in three areas based on crew activity and acoustical considerations. The first area is the quiet zone, which contains the crew quarters. The second area is a buffer zone for noise suppression, where the stowage, medical facilities, and personal hygiene facilities are located. The third area is the active zone which contains the galley/wardroom, laundry and exercise facilities. Each of these three areas will be discussed together with the applicable requirements, the common utility elements, and the man-systems hardware furnishings.

Controlled ecological life support systems (CELSS) which include higher plants for food and oxygen production are proposed for permanent manned space stations and long-duration space flights. A primary concern in the design and operation of such a life support system is maintaining plant health and maximizing plant growth rates. It is inevitable that a variety of microorganisms such as fungi and bacteria will be introduced into CELSS. A potential problem for plant growth systems is plant pathogenic microorganisms. Pathogens could cause major perturbations which would be highly undesirable in a closed life support system. In CELSS plant growth systems, microorganisms can not realistically be excluded, but they can be managed to favor beneficial microorganisms and exclude undesirable microorganisms. There are 5 principal methods of managing microorganisms in plant growth systems.

Due to the late flight opportunity for the BOTANY FACILITY on the second EURECA mission a sized down facility, referred to as the MINI BOTANY FACILITY (MBF), to be flown in a re-entering capsule, for example the Russian BIOKOSMOS, is currently being studied. As a minimum, the following subsystems are baselined for the MBF: Experiment container/-cuvette, visualization, illumination, life support, thermal control, waste control and fluid supply. The paper addresses firstly the impact of the new boundary conditions (e.g. operation in pressure controlled environment, much shorter mission duration) on the selection of viable concepts for the Life Support Subsystem (LSS). Next a number of options for soil moisture control is discussed and analysed. Finally, the pre-development of components and a miniaturized sensor for soil moisture is addresssed.

In order to minimize the mass of a spaceplane, fuel cells are being used instead of batteries. For HERMES the development of a state of the art fuel cell system which can operate under micro-gravity conditions is under way. A modular simulation program SANFU (System Analyzer for FUel cells) has been developed and applied within the HERMES fuel cell project. All major parameters which influence the component or system performance are taken into account and have been simulated: temperatures, heat and mass flow, chemical reactions within the fuel cell, electrical interfaces and controller logic. The improved simulation program now includes analyses on component and/or system level, modular exchange of components such as fuel cell stack, heat exchangers, pumps, electrolyte regenerators, valves, sensors, system and component controllers, electrical and thermal bus, etc. The network topology can be changed for example in order to optimize the system configuration.

Animal research on the Space Station presents the need for bioisolation, which is here defined as instrumental and operational provisions, which will prevent the exchange of particles greater than 0.3 μ size and microorganisms between crew and animals. Current design principles for the Biological Research Project thus call for: 1. use of specific pathogen-free animals; 2. keeping animals at all times in enclosed habitats, provided with microbial filters and a waste collection system; 3. placing habitats in a holding rack, centrifuge, and workbench, all equipped with particulate and odor filters, 4. washing dirty cage units in an equipment cleaner, with treatment and recycling of the water; 5. designing components and facilities so as to ensure maximal accessibility for cleaning; 6. defining suitable operational procedures. Limited ground tests of prototype components indicate that proper bioisolation can thus be achieved.

Since the space station operates inside closed environment over long periods of time, it is essential to develop technologies to control trace contaminants produced by the metabolism of the crew and by the materials from which it is made. In order to accomplish this objective, we first of all conducted studies of both the constituents and amounts of all the trace contaminants expected to appear, and then, on the basis of these studies, we discussed the optimum means of controlling them. As a result, we selected a combination of adsorption and catalytic oxidation as the technology to control these trace contaminants. We conducted adsorption experiments, catalytic oxidation experiments, and experiments to determine the effect on the catalyst capabilities of silicon and halogen constituents, which are thought to be catalytic poisons.

CUPOLA: /'KYUP∂L∂ 1. a: a rounded vault raised on a circular or other base and forming a roof or a ceiling- compare dome: b: a small structure built on top of a roof to provide interior lighting, to serve as a lookout… During the past 24 months, the concept of a space station cupola evolved from a small, bubble-type viewport into the primary location for proximity operations requiring direct, unobstructed viewing. Derived from a viewing analysis conducted by the Man-Systems Division at the Johnson Space Center, the cupola represents a solution for out-of-plane viewing which can not be provided by windows placed in the shell of the habitation and/or laboratory modules. An extended Man-Systems design study resulted in several cupola configurations, each illustrating an alternate solution to the required balance between viewing, projected space station operations and human/machine interface issues.

In covered structures and semiclosed ecological systems on earth, disease epidemics occur frequently because pathogens can spread so rapidly. Chemical pesticides greatly reduce epidemics but alternative measures are needed for space applications. Two strategies for control are exclusion and sanitation procedures to prevent invasion of deleterious microorganisms and gnotobiotic infestation with organisms that act both as biological control agents and as plant growth promoters.

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.