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The factors involved in the selection of a quick-disconnect are grouped into the following classifications for the purpose of discussion: (a) Functional considerations. (b) Weight considerations. (c) Environmental performance factors. (d) End fitting types. (e) Additional considerations.

A similar two-stage compressor for use in a long-life spacecraft cryocooler system has been under development at AiResearch since October 1985.

A general concept of designing an autonomous water system for interplanetary spaceships is proposed. The system features a high reliability resulting from the mutual complement and partial or complete backup of the elements. The system consists of three interconnected subsystems: water-supplies, regenerative physicochemical and biological ones, each providing the crew with water during different stages of a long-term space mission. The system is expected to be a further step in developing a closed-cycle, autonomous, biotechnologies life-support system.

The Comet Rendezvous Asteroid Flyby (CRAF) mission involves seven years of flight from 0.6 to 4.57 Astronomical Units (AU), followed by about 915 days of maneuvering around a comet. Ground testing will characterize the very critical attitude control system thrusters' fuel consumption and performance for all anticipated fuel temperatures over thruster life. The ground test program characterization will support flight condition monitoring. A commercial software application hosted on a commercial microcomputer will control ground test operations and data acquisition using a newly designed thrust stand. The data acquisition and control system uses a graphics-based language and features a visual interface to integrate data acquisition and control.

The factors involved in the selection of a quick-disconnect are grouped into the following classifications for the purpose of discussion: a Functional considerations. b Weight considerations. c Environmental performance factors. d End fitting types. e Additional considerations. A quick-disconnect coupling as used in this AIR is one that can be rapidly and repetitively connected and disconnected without excessive fluid loss. The relative importance of the design factors depends upon the fluid medium of the particular system in which quick-disconnect is to be used. The effect of the fluid media on each factor is discussed in this report where applicable.

A technique is presented to test heat pipe equipped spacecraft under any operational sun angle and orientation without adversely affecting the S/C power and temperature distribution that can occur when heat pipes are tilted in a 1-g test environment.

An advanced development helmet mounted display (HMD) was designed and fabricated under NASA-Johnson Space Center (NASA/JSC) contract, NAS 9-17543, by Hamilton Standard Division of United Technologies, Windsor Locks, CT. The work was initiated in December 1985 and culminated in June 1988 with the delivery of an extravehicular mobility unit (EMU) HMD demonstration unit as an alternative to the current low-resolution, chest-mounted display and cuff-mounted checklists. Important design goals achieved with this HMD include the use of transmissive liquid crystal display (LCD) image sources with fairly high resolution (i.e., text, graphics, and video compatible), binocular viewing with total image overlap, virtual image projection, low profile packaging, low power design, and demonstration of voice control of the HMD data.

A bioisolation system for rodent habitats has been developed that meets NASA requirements for the Centrifuge Facility planned for the Space Station. System performance was validated by realistic ground tests with a load of six live rats. Performance surpassed NASA requirements for every measured parameter including filter life, odor absorption, high efficiency particulate air (HEPA) filtration of particles including microbes, ammonia control, and the maintenance of specimen health and well-being. The bioisolation system has potential applications to other NASA habitats currently under development.

Leakage of fluids from systems has resulted in hazardous conditions at times, and the behavior of such compounds inside a spacecraft has taught us how to manage potentially harmful escapes should they occur. Potential combustion events are an ever-present threat to the wellbeing of the crew.

Space Shuttle missions STS-40 and STS-47, with their respective payloads of Spacelab Life Sciences-1 (SLS-1) and Spacelab Japan 1 (SL-J), used NASA's Spacelab module to provide an additional shirt-sleeve environment for the accomplishment of scientific activities. The Spacelab Transfer Tunnel connected Spacelab to the Orbiter Middeck. It represented the only way to translate between the two volumes and so provided the opportunity to examine microgravity travel between two specified points. Analyses utilized video of astronaut movement through the tunnel during regularly scheduled mission operations. Descriptions of translation techniques were generated, and translation times were recorded. The crew provided insights into tunnel translation and design through questionnaires and interviews. The design of the tunnel was satisfactory.

LISA (Laser Interferometer Space Antenna) is a constellation mission designed to detect gravitational waves using laser interferometry by measuring the laser path length between two free floating proof masses in opposing spacecraft separated by ∼5 million kilometers. As such, the LISA mission requires unprecedented thermal stability and, due to difficulties with ground testing, relies heavily on analysis.

A number of zero-gravity liquid-gas phase separators such as rotating units, elbow type units, porous plate, and the hydrophobic-hydraulic type discussed in this paper are presently being developed for spacecraft use. The basic theory of this unit is presented and the application of surface tension phenomenon is discussed as they apply to the design.

They are suitable for spacecraft thermal control where the mass, volume, and power budgets are very limited. The Canadian Space Agency is developing loop heat pipe hardware aimed at understanding the thermal performance of two-phase heat transfer devices and in developing numerical simulation techniques using thermo-hydraulic mathematical models, to enable development of novel thermal control technologies.

The selection of technologies for an evolutionary Space Station Freedom or a planetary (lunar or Martian) extravehicular mobility unit (EMU) are strongly driven by the system volume and weight as well as life cycle costs, reliability and safety. TDA Research, Inc. (TDA) is developing a compact, lightweight emergency system that provides 30-minute life-support in the case of system or component failures in the Portable Life Support System (PLSS). The system uses a low ventilation rate to reduce the amount of stored oxygen, reducing the associated weight and volume penalty. Operation of the system requires an effective sorbent that would remove carbon dioxide and moisture from the suit. We developed a regenerable sorbent that is suitable for the conceptual system. We also carried out a preliminary system analysis to show that the design saves significant weight.

These tests have been carried out with water (and their results are thus directly applicable to the most common fluids employed in spacecraft active thermal control) and have explored the range of low Reynolds numbers which are also directly applicable to the design of present spacecraft heat exchangers, and for which no test data has previously been published. ...These tests have been carried out with water (and their results are thus directly applicable to the most common fluids employed in spacecraft active thermal control) and have explored the range of low Reynolds numbers which are also directly applicable to the design of present spacecraft heat exchangers, and for which no test data has previously been published. This paper describes in detail the Technology Demonstrator design criteria, the test set-up and the test results obtained.

The conditions of space environment, especially high vacuum, and the high degree of reliability required are two important aspects of the problem of lubrication for space vehicles. Experiments have been made using conventional designs to achieve high reliability, and a narrow gap seal with a calculated oil loss instead of a rubbing contact seal. Two systems are evolved from theoretical considerations derived from the kinetic theory of gases. The experiments have validated the usefulness of this approach.

The new and extended challenges presented by the NASA Space Station Program require different approaches from the current Shuttle Program. The twenty plus year life span of the space station itself will necessitate that maintenance and repair of critical items occur on-orbit. In order to conserve crew time there should be a central location for maintenance and repair activities which contains the needed tools, equipment, and support functions. This centralized location would be a Maintenance Work Station (MWS) applicable to maintenance and repair activities which would take place onboard Space Station. Maintenance tasks could range from card replacement to a complete disassembly of a unit in order to locate the problem. This MWS must be integrated into an overall space station data management subsystem. In particular, direct communication with the inventory control management subsystem is important.

This paper deals with a man-made Gas Atmosphere (MMGA) Simulation Model developed and software presented for the Russian Segment of the International Space Station (ISS). The simulation Model (SM) is intended for analysis of the MMGA parameter nonstationary values in isothermal and non-isothermal conditions under a variable number of crew taking into account the intensities of the crew activity. The person's structure of the SM, basic assumptions, taken for modeling and formalized descriptions of SM separate modules. Formalized descriptions by the Segment's Pressurized Modules are based on using the nonlinear equations of mass/energy balance for the controlling volume, taking into account all main sources and sinks of the environment separate components, which are a crew, Integrated Regenerative Life Support System (IRLSS) separate subsystems, ISS on-board systems.

Mathematical modeling of the Ni-H2 cell based on the fundamental electrochemical processes is necessary for accurately simulating the battery behavior on Space Station Freedom. Accurate predictions are incorporated as part of the development of the Space Station Electric Power System simulation. This simulation will be used to develop and test control algorithms which will maximize the available power in the most efficient way. This is a deviation from the approach used on smaller satellite power systems which are designed with substantial margin. Hence, the use of an empirical battery model is not feasible due to its low fidelity. This paper covers the electrochemical theory related to the Ni-H2 cells, and the analysis of experimental data used to develop relations between the cell state of charge and certain cell properties. Theoretical results are compared against well-documented experimental data.

A system was developed which provides nutrients and water to plants while maintaining good aeration at the roots and preventing water from escaping in reduced gravity. The nutrient solution is circulated through porous tubes under negative pressure and moves through the tube wall via capillary forces into the rooting matrix, establishing a non-saturated condition in the root zone. Tests using prototypes of the porous tube water and nutrient delivery system indicate that plant productivity in this system is equivalent to standard soil and solution culture growing procedures. The system has functioned successfully in short-term microgravity during parabolic flight tests and will be flown on the space shuttle. Plants are one of the components of a bioregenerative life support system required for long duration space missions.