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The Portable Fire Extinguisher (PFE) is used to displace oxygen and cool a closed volume to prevent/eliminate a fire hazard on the International Space Station (ISS). An analysis and test was performed on the discharge characteristics of the PFE system on a payload rack volume. Analytical data was developed to support the test data and determine the real versus ideal gas state of the carbon dioxide (CO2) during discharge into the rack. This paper presents the analytical and test data for PFE discharge to determine applicability of this system to rack and open volume fires with respect to mass discharged, local area concentration, temperature, and displacement volume. Ancillary to this analysis is a consideration of the local open volume carbon dioxide concentration and the probable impact on the crew and atmosphere revitalization and supply system for ISS. This report will include testing data recently performed at Marshall Space Flight Center (MSFC).

The Vacuum Access System (VAS) is used for ISS experiment chamber evacuations and to remove air from furnace experiment sleeves. The evacuation process thermodynamically reduces the temperature of the gas being evacuated which then cools the temperature of attached hardware. This cooling effect can present problems to the environment if it reaches the local ambient dewpoint temperature. This paper presents real and ideal gas thermodynamic relationships as an application to determine the discharge characteristics of the VAS evacuation process and determine the heat transfer rate to the surrounding and attached hardware.

The design requirements for the water treatment systems aboard the International Space Station (ISS) include and require recycling as much water as possible and to treat the water for intentional contamination (hygiene, urine distillate, condensate, etc.) and unintentional contamination in the form of biofilm and microorganisms. As part of an effort to address the latter issue, a biofilm system was developed by Marshall Space Flight Center (MSFC) to simulate the conditions aboard ISS with respect to materials, flowrates, water conditions, water content, and handling. The tubing, connectors, sensors, and fabricated parts included in the system were chosen for specific attributes as applicable to emulate an orbital water treatment system.

As manned spacecraft have evolved into larger and more complex configurations, the mandate for preventing, detecting, and extinguishing on-board fires has grown proportionately to ensure the success of progressively ambitious missions. The closed environment and high value of manned spacecraft offer the Fire Detection and Suppression (FDS) systems designer significant challenges. With the presence of Oxygen (O2), flammable materials, and ignition sources, it is impossible to completely remove the likelihood of a spacecraft fire. Manned spacecraft contain these three ingredients for fire; therefore, it becomes profitable to review past designs of FDS systems and ground testing to determine system performance and lessons learned in the past for present and future applications.

As the complexity of manned spacecraft increases, close consideration of Environmental Control and Life Support (ECLS) systems design becomes important. Mission design topics and flight performance data for a subset of the overall ECLS system, the Air Handling and Atmosphere Conditioning (AH&AC) system, are presented to aid in designing systems for future manned missions. Included are such topics as crew habitable volumes, air circulation velocities, atmospheric pressures, electrical component and metabolic cooling, ventilation fan designs, and contaminant removal systems. The condensed information in this paper represents the first step in a much larger internal study with the goal of optimizing the design and efficiency of physical/chemical life support systems, using flight data and “lessons learned” to support this goal.

The Water Recovery and Management (WRM) system on Space Station Freedom (SSF) is modeled using SINDA '85/FLUINT to determine its hydraulic operation characteristics, and to verify the design flow and pressure drop parameters. The WRM system consists of the Potable Use water, Waste water, and Fuel Cell loops, as well as the Fluid Management System and experiments, which are not included in this model. This system will be the first closed loop water regeneration system used in space flight. The water is driven in each loop by storage tanks pressurized with cabin air, and is routed through the system to the desired destination. The model considers the flow of water from the storage tanks to the use points and back, as determined by each individual flow diagram for the Permanently Manned Configuration (PMC) phase of SSF.