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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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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
NASA NTRS1998

Space Station Radiator Test Hosted by NASA Lewis at Plum Brook Station

In April of 1997, the NASA Lewis Research Center hosted the testing of the photovoltaic thermal radiator that is to be launched in 1999 as part of flight 4A of the International Space Station. The tests were conducted by Lockheed Martin Vought Systems of Dallas, who built the radiator. This radiator, and three more like it, will be used to cool the electronic system and power storage batteries for the space station's solar power system. Three of the four units will also be used early on to cool the service module.

Speth, Randall C.↗
NASA NTRS2012

Three Canted Radiator Panels to Provide Adequate Cooling for Instruments on Slewing Spacecraft in LEO

Certain free-flying spacecraft in low Earth orbit (LEO) or payloads on the International Space Station (ISS) are required to slew to point the telescopes at targets. Instrument detectors and electronics require cooling. Traditionally a planar thermal radiator is used. The temperature of such a radiator varies significantly when the spacecraft slews because its view factors to space vary significantly. Also for payloads on the ISS, solar impingement on the radiator is possible. These thermal adversities could lead to inadequate cooling for the instrument. This paper presents a novel thermal design concept that utilizes three canted radiator panels to mitigate this problem. It increases the overall radiator view factor to cold space and reduces the overall solar or albedo flux absorbed per unit area of the radiator.

Choi, Michael K.↗
NASA NTRS1985

Four K refrigerators with a new compact heat exchanger

Two refrigerators have been developed which have nominal cpacities of 0.25M and 0.5W at 4.2K. These use standard two stage Displex sup R expanders and compressors combined with a new compact heat exchanger which is concentric with the expander cylinder. These refrigerators can be used to cool superconducting electronic devices by direct attachment to the 4K heat station, or they can be plugged into the neck of a liquid helium superconducting magnet cryostat where they can cool the radiation shields and reliquefy helium.

Longsworth, R. C.↗
NASA NTRS1958

X-15 conditioning and pressurization system

The cooling system for the X-15 airplane incorporates insulation partial protection against high-temperature effects plus liquid and gaseous nitrogen to control specifically environmental and equipment temperatures. Electronic-equipment cooling represents the largest load; however, other items to be considered are the pressure-suit ventilation, aerodynamic-heating effects, sensor-head cooling, and windshield antifogging. A review of various types of cooling systems indicates that an expendable, stored, cooling system is the most efficient for short-duration missions. This paper presents a description including a simplified schematic diagram of the subject system. (author)

Bouman, C P↗
NASA NTRS1983

Evolution of electron and proton temperatures in a flaring loop. I - A case of thermal heating of electrons

A temperature difference between electrons and protons produced in a flaring loop was investigated experimentally by adopting a one-fluid, two-temperature model instead of a single-temperature model. Consideration was given to the case in which flare energy is released in the form of heating of electrons located in the top part of the loop. In this case, a large temperature difference appears in the corona in the energy-input phase of the flare. When the material evaporated from the chromosphere fills the corona, the temperature difference in the loop begins to shrink rapidly from below. Eventually, in the loop apex, the proton temperature exceeds the electron temperature mainly due to cooling of the electrons by conduction down the loop and heating of the protons by compression of the ascending material. In the late phase of the flare (about 15 min from the flare onset), the temperature difference becomes less than 2 pct of the mean temperature of electrons and protons at every point in the loop.

Nagai, F.↗
NASA NTRS2001

Mars Pathfinder mechanically pumped cooling loop

A mechanically pumped single-phase cooling loop was successfully flown on the Mars Pathfinder (MPF) Spacecraft which safely landed on the Martian surface on July 4, 1997. One of the key technologies that enabled the mission to succeed was an active heat rejection system (HRS) used to cool the electronics on the spacecraft during its seven-month cruise from Earth to Mars.

spacecraft tehermal control pumped cooling loop↗
NASA NTRS1995

Wet/Dry Vacuum Cleaner

Vacuum cleaner collects and retains dust, wet debris, and liquids. Designed for housekeeping on Space Station Freedom, it functions equally well in normal Earth Gravity or in microgravity. Generates acoustic noise at comfortably low levels and includes circuitry that reduces electromagnetic interference to other electronic equipment. Draws materials into bag made of hydrophobic sheet with layers of hydrophilic super-absorbing pads at downstream end material. Hydrophilic material can gel many times its own weight of liquid. Blower also provides secondary airflow to cool its electronic components.

Reimers, Harold↗
NASA NTRS1993

Polytropic relationship in interplanetary magnetic clouds

High time-resolution data from the ISEE 3 and IMP 8 spacecraft are presented for the magnetic field and the proton and electron populations of a number of magnetic clouds, in order to investigate such clouds' thermodynamics and the relationship between their magnetic and thermodynamic structures. It is judged on the basis of these data that while the magnetic flield of the cloud expands, the ions are cooled. Hot electrons are trapped by the magnetic field in the magnetic cloud's core. These conditions are favorable for the generation of ion-acoustic waves.

Osherovich, V. A.↗
NASA NTRS1972

Heat pipe applications for the space shuttle.

Discussion of six specific applications for heat pipe (HP) devices on the space shuttle. These applications were chosen from 27 concepts formulated as part of a study to evaluate the potential benefits associated with HP use. The formulation process is briefly described along with the applications which evolved. The bulk of the discussion deals with the 'top' six - namely, HP radiators for waste heat rejection, an HP augmented cold rail, an HP circuit for electronic equipment cooling, modular heat sink for control of remote packages, an HP temperature control for compartments, and air-cooled equipment racks. The philosophy, physical design details, and performance data are presented for each concept along with a comparison with the baseline design where applicable.

Tawil, M.↗
NASA NTRS1972

Surface composition of magnetic neutron stars.

The relative abundances of seven constituent nuclei, He4, C12, O16, Ne20, Mg24, Si28, and Fe56, are calculated as a function of time for neutron star atmospheres within which exist magnetic fields of the order of 10 to the 13th G. The opacity, equation of state of the electrons, and cooling rate of the magnetic star are discussed, and it is shown to be a reasonable approximation to assume an atmosphere to be isothermal. The effects of particle diffusion are included in the nuclear reaction network. Computations are performed both for a constant mass atmosphere and for an atmosphere in which mass is being ejected. It is found that the final abundances are model-independent, as long as the initial model contains predominantly He4. The relative abundances are compared to the cosmic ray spectrum. For both the constant-mass and mass-loss atmospheres, nucleosynthesis proceeds virtually completely to Fe56. However the outermost layers of the envelope, in which no mass is being ejected, are composed almost entirely of He4 with trace amounts of Fe56. After the loss of about 10 to the 21st g, only Fe56 is ejected from atmospheres expelling mass.

Rosen, L. C.↗
NASA NTRS1974

Heat Pipe Technology: A bibliography with abstracts

This bibliography lists 149 references with abstracts and 47 patents dealing with applications of heat pipe technology. Topics covered include: heat exchangers for heat recovery; electrical and electronic equipment cooling; temperature control of spacecraft; cryosurgery; cryogenic, cooling; nuclear reactor heat transfer; solar collectors; laser mirror cooling; laser vapor cavitites; cooling of permafrost; snow melting; thermal diodes variable conductance; artery gas venting; and venting; and gravity assisted pipes.

Source record↗
NASA NTRS1977

Accelerated life tests of specimen heat pipe from Communication Technology Satellite (CTS) project

A gas-loaded variable conductance heat pipe of stainless steel with methanol working fluid identical to one now on the CTS satellite was life tested in the laboratory at accelerated conditions for 14 200 hours, equivalent to about 70 000 hours at flight conditions. The noncondensible gas inventory increased about 20 percent over the original charge. The observed gas increase is estimated to increase operating temperature by about 2.2 C, insufficient to harm the electronic gear cooled by the heat pipes in the satellite. Tests of maximum heat input against evaporator elevation agree well with the manufacturer's predictions.

Tower, L. K.↗
NASA NTRS1979

Low-altitude signatures of the boundary layers

Low altitude measurements reveal two distinct types of dayside boundary-layer plasmas. The first type is characterized by a proton distribution whose average energy decreases with increasing latitude and generally shows cool, unaccelerated electron fluxes. This type is observed only near noon and is correlated with southward interplanetary magnetic field (IMF). The second type is characterized by a 'V' signature in which the proton average energy first decreases then briefly increases as a function of latitude. The electron distribution in the latter case is hotter and often shows evidence of small scale acceleration regions. This type can be seen at all local times in the dayside and at noon is correlated with a northward IMF. It is suggested that the type 1 plasma is the low altitude signature of the plasma mantle and the type 2 plasma is the low altitude signature of the low latitude boundary layer.

Reiff, P. H.↗
NASA NTRS1982

Design, fabrication and test of liquid metal heat-pipe sandwich panels

Integral heat-pipe sandwich panels, which synergistically combine the thermal efficiency of heat pipes and the structural efficiency of honeycomb sandwich panel construction, were fabricated and tested. The designs utilize two different wickable honeycomb cores, facesheets with screen mesh sintered to the internal surfaces, and potassium or sodium as the working fluid. Panels were tested by radiant heating, and the results indicate successful heat pipe operation at temperatures of approximately 922 K (1200 F). These panels, in addition to solving potential thermal stress problems in an Airframe-Integrated Scramjet Engine, have potential applications as cold plates for electronic component cooling, as radiators for space platforms, and as low distortion, large area structures.

Basiulis, A.↗
NASA NTRS1982

The development and applications of charge-coupled devices for space astronomy

The developments in charge-coupled device technology over the past decade are reviewed, with emphasis on the relevance of these developments to astronomical applications. The characteristics and limitations of current commercial devices are described, and the future requirements on CCDs for space astronomy are summarized for the X-ray and near UV, optical, and infrared wavelength ranges. Emphasis is placed on the commonality of technological development which is called for, including the issues of quantum detection efficiency (photon entrance and depletion depth), charge transfer efficiency, modulation transfer function, output noise level, and array size. The system requirements on focal plane instrumentation for space astronomy are summarized, and shown to have much in common for the different wavelength bands. These requirements are discussed in terms of CCD mosaicing, cryogenic cooling, and electronics. The overlap in CCD developments in the defense, astronomical and commercial arenas is summarized.

Griffiths, R. E.↗
NASA NTRS1983

Design, fabrication and test of liquid metal heat-pipe sandwich panels

Integral heat-pipe sandwich panels, which synergistically combine the thermal efficiency of heat pipes and the structural efficiency of honeycomb sandwich panel construction, were fabricated and tested. The designs utilize two different wickable honeycomb cores, facesheets with screen mesh sintered to the internal surfaces, and potassium or sodium as the working fluid. Panels were tested by radiant heating, and the results indicate successful heat pipe operation at temperatures of approximately 922K (1200F). These panels, in addition to solving potential thermal stress problems in an Airframe-Integrated Scramjet Engine, have potential applications as cold plates for electronic component cooling, as radiators for space platforms, and as low distortion, large area structures.

Basiulis, A.↗
NASA NTRS1987

A new model of cometary ionospheres

The coupled continuity, momentum, and energy equations were solved for ionospheric conditions appropriate for Comet Halley at 1 AU. The numerical scheme used is such that any shock transition appears naturally in the solution and no a priori assumptions are necessary. Solutions were obtained for a number of different assumptions concerning electron heating rates, but all showed that the electron temperatures increase rapidly and significantly at a distance from the nucleus where collisional electron-neutral cooling becomes unimportant. This temperature increase is accompanied by a sharp increase in both the plasma pressure and its associated polarization electric field, causing the supersonic plasma flow to go subsonic. It is not clear at this time whether or not this sonic transition is accompanied by a shock.

Korosmezey, A.↗