SEARCH · Search NASA
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Inverted tee, installed at a high point in a cryogenic transfer line, is equipped with an insulated bleed line that passes a fixed amount of cryogenic fluid at atmospheric pressure. A sensing device activates a vent valve in the tee stack whenever gaseous nitrogen is present.
Flowgraph construction, input-output formulation, and subroutines for Network Analysis for Systems Applications Program /NASAP/
Ecology of meteoritic material in solar system involving immediate origin and dissipation
Low leakage rate, large diameter vent and relief valve operates satisfactorily over a large temperature range by a design that accommodates waviness and distortions due to thermal gradients. It is based on a fixed sealing member having an inclined lapped surface to which a flexible flow gate conforms.
Program control methods for reliability of Apollo spacecraft systems
Maintenance task analyses and expendables data on long duration, manned spacecraft flights
NASAP /Network Analysis for System Application Program/ functions capabilities
Sampled-data regulator for investigating both steady-state and transient responses of respiratory system of humans to reduced oxygen at fixed levels of carbon dioxide
Pressure formed as the cryogenic liquid vaporizes is used to pump new cryogenic liquid from a storage reservoir. Changes in volume of a gas resulting from changes in temperature actuate a valve which either replenishes the depleted liquid in the vessel or vents the evolving gas to the atmosphere.
Simulation of cargo transfer in weightlessness environment
Experimental study of effects of variable-length training sessions on physical fitness in college men
Sampled data regulator for maintenance of constant alveolar carbon dioxide during steady state and transient ventilatory responses to hypoxic stimulation
Explore the source record for details and available documents.
Bone mineral changes in prolonged bed rest subjects determined by gamma ray absorption technique
NASA Office of Tracking and Data Acquisition mission support and ground and spacecraft communication networks
Increased artificial gravity avoidance by squirrel monkeys with variations in rotation rate and radius
The six most promising valve, regulator, and remote coupling concepts, representing the more radical designs from twenty concepts generated, were investigated. Of the three valves, one has no moving parts because shutoff sealing is accomplished by an electromagnetic field which ionized the flowing fluid. Another valve uses liquid metal to obtain sealing. In the third valve, high sealing forces are generated by heating and expanding trapped hydrogen. The pressure regulator is an electronically controlled, electromechanically operated, single state valve. Its complexity is in electronic circuitry, and the design results in less weight, increased reliability and performance flexibility, and multipurpose application. The two remote couplings feature the minimization of weight and mechanical complexity. One concept uses a low melting temperature metal alloy which is injected into the joint cavity; upon solidification, the alloy provides a seal and a structural joint. The second concept is based on the differential thermal expansion of the coupling mating parts. At thermal equilibrium there is a predetermined interference between the parts, and sealing is achieved by interference loading.
Review of the long-life and minimum-turnaround-maintenance features in the design of the Space Shuttle Orbiter main engine aimed at reducing the latter's field operating costs. These features include the regeneratively cooled hot-gas system selected, the provision of additional fatigue margins in the design of rotating machinery elements, and employment of a proven approach to engine condition monitoring for fault detection and identification.