Space cabin atmospheres
Space cabin atmospheres - physical and physiological variables
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Space cabin atmospheres - physical and physiological variables
Selection of space cabin atmospheres including pressure, fire and blast hazard, humidity and temperature control, etc
Space cabin atmospheres - space cabin aerosol sampling device, field aerosol generator, and survey of particle counter designs
Selection of space cabin atmospheres - oxygen toxicity
Rats exposed to space cabin atmosphere for two weeks, noting mortality rate, organism functioning, growth rate, etc
Physiological factors of inert gases in space cabin atmospheres
Role of fire and blast hazards in selection of space cabin atmosphere
Reactions of animals exposed to pure oxygen space cabin atmosphere for 235 days, noting no systematic toxicity
Performance characteristics of aerosol generator, and distribution sampling errors of electrostatic precipitator sampling device for space cabin atmosphere
Physiological factor, hardware, and environmental control tradeoffs for one and two gas systems of space cabin atmospheres
Semiconducting polymer film preparation and use in contaminant detector for space cabin atmosphere
Aerosol generation for instrument calibration, calibration of aerosol particle analyzers, data analysis computer program, and particle monitoring in space cabin atmosphere study
The rapid evolution of aircraft and, lately, space vehicles has brought with it the ever-increasing difficulty of designing for prevention of fires and explosions. The present-day sealed cabin with its limited work space, unusual atmospheric constituents, and lack of flexibility in emergency situations has brought new and ill-defined hazards into the picture. In the past, numerous data have been compiled on the fire and explosion characteristics of all things combustible. Unfortunately, much of the material is not pertinent to the actual operational problems in space. The confusion and controversy arising from attempts to evaluate the space-cabin fire problem appear to stem from past failure to compile the scattered data and to expose it to critical review and selection. In the compilation that follows, an attempt has been made to review the best available data that was deemed actually pertinent to the present problem. The effects of unusual atmospheres have been emphasized, but, as will soon be evident, other physical parameters also play a major role in determining the nature of the problem. Chapter 1 contains a discussion of pertinent definitions and theory. This is detailed only to the point of anticipating some of the problems of interpretation that may arise in other chapters of the report. Included in this chapter is speculation on the impact of unusual environmental conditions such as aerodynamic heating, reduced gravitational acceleration, and low ambient pressures. Chapter 2 covers flammable fabrics and carbonaceous solids; Chapter 3, specific fire hazards involving flammable liquids, vapors, and gases; and Chapter 4, electrical fires. Chapter 5 covers the fire, blast, and flash hazards from meteoroid penetration; and Chapter 6, the problems of fire prevention and extinguishment in space cabins. Chapter 7 reviews the factors of fire and blast hazards in selection of a space-cabin atmosphere.
Ground level denitrogenation duration effects on decompression sickness occurrence in space cabin atmospheres
An analytical study of the theory of ignition and burning of a plastic material immersed in an atmosphere of a space cabin which may be subjected to gravity force changes is considered. The hazardous condition in a space cabin environment where the changes of gravity may effect the combustion process is evaluated. The model considered the analysis of the coupled gas and solid phases and is based on the premise that material heating leads to the formation of pyrolysis gases from the decomposed solid which then react with the ambient oxidizer to further the combustion process. Moreover, free convection plays a dominant role in transporting these hot gases to the virgin material. A time-dependent study of the coupled gas-solid model as required for ignition processes with emphasis on the surface energy interchange of the gas and solid phases has been made. Detailed distribution of species composition and temperature patterns provide a spatial and time map of the evolving gases from the material combustion.
An atmosphere control subsystem (ACS) was developed for use in a closed manned cabin, such as the Space Shuttle Orbiter. This subsystem uses the Perkin Elmer mass spectrometer for continuous measurement of major atmospheric constituents (H2, H2O, N2, O2, and CO2). The O2 and N2 analog signals are used as inputs to the controller, which produces a pulse-frequency-modulated output to operate the N2 gas admission solenoid valve and an on-off signal to operate the O2 valve. The proportional controller characteristic results in improved control accuracy as compared with previously used on-off controllers having significant dead-band. A 60-day evaluation test was performed on the ACS during which operation was measured at various values of control setpoint and simulated cabin leakage.
Calibration of hot-wire detector for particle concentration and size distribution in closed spacecraft cabin atmospheres
Aerosol measurements in closed cabin environment optimizing geometry of aerosol particle analyzer, and calibrating hot-wire droplet sensor