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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Subsystem was developed for breathing metabolic simulator which adjusts temperature and humidity of air to levels of human exhaled breath. Temperature-humidity subsystem is described, consisting of aluminum enclosure with 400 watt heat sheet glued to bottom, vertical separators, inlet connection, and check valve.
Portable prebreathing system was developed which recirculates and reconditions respiratorily exhaled oxygen. Apparatus reduces fire hazards, simplifies prebreathing procedures, and does not require extensive enclosure venting system usage.
A hydrogen maser clock is proposed for enclosure in an orbiting satellite to measure the gravitational effect on time scales with high accuracy. This experiment is used to test the principle of equivalence for clocks in space. Extremely narrow linewidth of Fe-57 radiation and absorption due to Mossbauer effect over 75 ft vertical distance was used to confirm the prediction of the equivalence principle to 1 part in 100. The fractional frequency shift of a satellite-borne oscillator observed from earth is also given.
An experimental portable system used to control surgically induced infections is described. The system consists of a portable clean room comprised of a laminar flow filter system consistent with Federal standards; a helmet-shoulder pad assembly; a communication system; a helmet ventilation system; a transparent walled enclosure; and surgical gowns. Guidelines for the set up and operation of such equipment are given along with corrective steps to use in case of system malfunctions. Cleaning procedures, maintenance requirements, and disassembly and transfer particulars are included.
The methods employed by NASA to establish configuration control of nonmetallic materials on Apollo spacecraft are described. A five step procedure for examining contractor materials for suitability and compatibility is presented. The compatibility of the materials with the oxygen enriched environment of the spacecraft enclosures is emphasized.
The applications of nonmetallic materials to the structures of Apollo spacecraft are discussed. The spacecraft components are examined and the rationale behind the use of specific nonmetallic materials is presented. The emphasis is on the compatibility of the materials with the oxygen enriched atmosphere of the spacecraft enclosures.
The systems approach was used in the seminar on the complex multidisciplinary problem of housing and related environment conditions. The main areas of study are the following; historical overview of housing; diagrammatic presentation of the problem; technological innovations and contributions; management, economic, legal, and political considerations; environment and natural resources; human needs and behavior; model of the housing industry; and potential for implementation. It is felt that a greater attempt should be made to transfer aerospace technology to the housing industry; however, the emphasis of the conference was directed to the modern management techniques developed by NASA. Among the conclusions are the following: The extent and character of the housing problem should be defined. Increased coordination of housing programs within and between Federal agencies is essential. Development of physically sophisticated building systems requires Federal support. New towns of differing life styles need to be created. Physiological and psychological reactions to environmental enclosure need to be defined.
An experimental system was developed for evaluation of the effects of aerodynamic heating and cooling, vacuum, and pressure loading on candidate insulation packages proposed for use on the space shuttle. The system includes a number of design features which facilitate rapid recycle times. This is necessary to efficiently conduct extensive thermal cycling tests on these insulation packages to determine their reuse capabilities. The heart of the system is a 26-inch graphite element radiant heater. A susceptor plate functions as a uniform-temperature intermediate radiating surface. The susceptor also forms the lid of an inert atmosphere enclosure which separates the heater from the oxidizing test atmosphere. In some tests the plate properly simulates the heating from an actual flight heat-shield panel. Although other materials were used at lower required test temperatures, 2500 F was routinely achieved using a coated columbium susceptor plate.
The experimental system is described, and the procedures for surgery usage and maintenance are outlined. Basically the system consists of the following: (1) a portable clean room comprised of a horizontal laminar flow filter system and a transparent walled enclosure, (2) a helmet-shoulder pad assembly, (3) a communications system, (4) a helmet ventilation system, and (5) surgical gowns.
Experiments were performed to determine the influence closed microbial ecologies have on modification or simplification of natural intestinal flora of ferrets in a closed environmental system. On the basis of previous tests in which certain species (Salmonella and Bacteroides) were decreased at 90 days of enclosure, a second trial was constructed for 180-day tests. In this trial there was little difference in the 8 major classes of intestinal flora between animals in the Open and Closed environmental groups except for the level of Lactobacillus. It is of extreme importance to note that when both Open and Closed groups contracted hemorrhagic gastritis, the interrelationship of this agent with other intestinal flora produced a more profound effect on animals from the Closed Group, particularly with reference to Lactobacillus levels.
A comprehensive, generalized two-dimensional RTG analysis computer program was developed. This program is capable of analyzing any specified RTG design under a wide range of transient as well as steady-state operating conditions. The feasibility of a new concept for the design of segmented (or single-phase) thermoelectric couples was demonstrated. A SiGe-PbTe segmented couple involving pressure contacted junctions at the intermediate- and hot-junction temperatures was successfully encapsulated in a hermetically sealed bellows enclosure. This bellows-encapsulated couple was operated between a hot- and cold-junction temperature of 1200 K and 450 K, respectively, with a measured energy conversion efficiency of 7.6 + or - .5 per cent. An experimental study of selected sublimation barrier schemes revealed that a significant reduction in the sublimation rate of p-type PbTe could be achieved by using multiple layers of SiO2 fibers. A comparison of the barrier effectiveness is given for three different barrier designs.
A device to simulate the vibrational and acoustical properties of a sonic boom was developed and evaluated. The design employed a moving circular diaphragm which produced pressure variations by altering the volume of an air-tight enclosure that was located adjacent to an acoustical test chamber. A review of construction oriented problems, along with their solutions, is presented. The simulator is shown to produce the effects of sonic booms having pressure signatures with rise times as low as 5 milliseconds, durations as short as 80 milliseconds, and overpressures as high as 2.5 pounds per square foot. Variations in the signatures are possible by independent adjustments of the simulator. The energy spectral density is also shown to be in agreement with theory and with actual measurements for aircraft.
Design and performance of an analytical system for the evaluation of certain environmental constituents in critical environmental areas of the Quality Reliability and Assurance Laboratory are reported. Developed was a self-contained, integrated, minimum sized unit that detects, interrogates, and records those parameters of the environment dictated for control in large storage facilities, clean rooms, temporarily curtained enclosures, and special working benches. The system analyzes humidity, temperature, hydrocarbons particle size, and particle count within prescribed clean areas.
Two specific applications are discussed of microbial contamination control in planetary quarantine. Under the first concept, using the clean room to control environmental microorganisms, the objective is to reduce the microbial species and keep the numbers of microorganisms within an enclosure at a low level. The clean room concept is aimed at obtaining a product that has a controlled and reduced level of microbial contamination. Under the second concept, using the microbiological barrier to control microbial contamination of a specific product, the barrier techniques are designed to prevent the entry of any microorganisms into a sterile work area. Thus the assembly of space flight hardware within the confines of a microbiological barrier is aimed at obtaining a sterile product. In theory and practice, both approaches are shown to be applicable to the planetary quarantine program.
Description of an experimental dual resonant cavity absorption cell for observing microwave spectroscopic double-resonance effects. The device is composed of two Fabry-Perot interferometers excited by independent microwave sources and mounted at right angles in a suitable vacuum enclosure. The pumping transition is modulated by one source and the modulation induced on the rf absorption in the orthogonal cavity is detected.
Examination of the directional effects of the simplified models by comparing the experimental data with the predictions based on simple and more detailed models for the radiation characteristics of surfaces. Analytical results indicate that the constant property diffuse and specular models do not yield the upper and lower bounds on local radiant heat flux. In general, the constant property specular analysis yields higher values of irradiation than the constant property diffuse analysis. A diffuse surface in the enclosure appears to destroy the effect of specularity of the other surfaces. Semigray and gray analyses predict the irradiation reasonably well provided that the directional properties and the specularity of the surfaces are taken into account. The uniform and nonuniform radiosity diffuse models are in satisfactory agreement with each other.
Peltier effect, Thomson effect, and Seeback effect are utilized in design of thermal control coating that serves as versatile means for controlling heat absorbed and radiated by surface. Coatings may be useful in extreme temperature environment enclosures or as heat shields.
Simple, inexpensive, lightweight enclosure traps upward long wave radiation of earth while reflecting harsh solar radiation in upper atmosphere. It warms enclosed instruments in cold regions and protects them from overheating during the day. Device can be attached to balloon system without any changes in experimental design.