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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 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
NASA NTRS1983

Test for contamination of MgF2 - coated mirrors

Graphs show preflight and postflight reflectivities in percent for exposed and covered mirrors carried on the OSS-1 payload pallet during STS-3. No changes greater than 1.8 sigma were observed except for a fingerprint. Weak evidence for degradation at 1216 A and 1600 A was found in several samples. There was no difference between flight mirrors and control mirrors. Covered samples suffered more than samples exposed to the Sun, but the differences are barely significant. The exposed side of the flight mirrors were somewhat dusty. No evidence was found for permanent solar-induced or shuttle-induced deterioration. There also was no evidence on oil-pumped vacuum versus oil-free vacuum during coating.

Bunner, A. N.↗
NASA NTRS1983

Vehicle charging and potential on the STS-3 mission

An electron gun with fast pulse capability was used in the vehicle charging and potential experiment carried on the OSS-1 pallet to study dielectric charging, return current mechanisms, and the techniques required to manage the electrical charging of the orbiter. Return currents and charging of the dielectrics were measured during electron beam emission and plasma characteristics in the payload bay were determined in the absence of electron beam emission. The fast pulse electron generator, charge current probes, spherical retarding potential analyzer, and the digital control interface unit which comprise the experiment are described. Results show that the thrusters produce disturbances which are variable in character and magnitude. Strong ram/wake effects were seen in the ion densities in the bay. Vehicle potentials are variable with respect to the plasma and depend upon location on the vehicle relative to the main engine nozzles, the vehicle attitude, and the direction of the geomagnetic field.

Williamson, R.↗
NASA NTRS1983

STS-3/OSS-1 Plasma Diagnostics Package (PDP) measurements of the temperature pressure and plasma

Designed to withstand the thermal extremes of the STS-3 mission through the use of heaters and thermal blankets, the plasma diagnostics package sat on the release/engagement mechanism on the OSS-1 payload pallet without a coldplate and was attached to the RMS for two extended periods. Plots show temperature versus mission elapsed time for two temperature sensors. Pressure in the range of 10 to the -3 power torr and 10 to the -7 power torr, measured 3 inches from the skin of the package is plotted against GMT during the mission. The most distinctive feature of the pressure profile is the modulation at the obit period. It was found that pressure peaks when the atmospheric gas is rammed into the cargo bay. Electric and magnetic noise spectra and time variability due to orbiter systems, UHF and S-band transmitter field strengths, and measurements of the ion spectra obtained both in the cargo bay and during experiments are plotted.

Shawhan, S. D.↗
NASA NTRS1983

STS-3/OSS-1 Plasma Diagnostics Package (PDP) measurements of Orbiter transmitter and subsystem electromagnetic interference

The plasma diagnostics package receiver system is described to identify the various antennas and to characterize the complement of receivers which cover the frequency range of 30 Hz to 800 Hz and S-band at 2200 + or - 300 MHz. Sample results are presented to show the variability of electromagnetic effects associated with the orbiter and the time variability of these effects. The electric field and magnetic field maximum and minimum field strength spectra observed during the mission at the pallet location are plotted. Values are also derived for the maximum UHF transmitter and S-band transmitter field strengths. Calibration data to convert from the survey plots to actual narrowband and broadband field strengths are listed.

Shawhan, S. D.↗
NASA NTRS1983

Results of thermal environment measurements on the thermal cannister experiment and get away special enclosure

Because the OSS-1 pallet contained a variety of instruments with irregular surface geometry and properties which limited predictability, the total absorbed flux on thermal canister radiators was measured to determine heat rejection capability. The instrumentation and sensor cup design and locations for the thermal canister experiment are illustrated. Graphs show flux sensor history in hot and coal orbits. Kapton erosion is also considered. Results show that the flux levels measured in all STS attitudes are higher than predictions. In cold and moderate attitudes, flight results are a factor of two to three higher than predicts. In hot attitude, much better agreement occurred. It is concluded that in cold or moderate attitudes other sources may be contributing to added inputs (albedo, Earth shine, shuttle background). In hot attitude, smaller differences could be attributed to coatings assumptions or calculation uncertainty.

Ollendorf, S.↗
NASA NTRS1982

Spacelab-1: An early space station for science and technology

The scientific capabilities of the Spacelab manned pallet are reviewed, together with the implications of an expansion of the research effectiveness with a free-flying platform. The premier Spacelab flight will carry out earth observations with a metric camera and SAR, atmospheric studies will be performed with imaging spectrometers, and space plasma physics will be examined by injecting particle beams or VLF waves into the near-Shuttle environment. Radiance and spectrum data will be gathered of the sun and UV and X ray information will be recorded from the stars. Experimentation will also be carried out for on-board crystal growth, metallurgy, and glassy material production, as well as the response of biological systems to zero-g conditions and hard space radiation. The telemetry, time, crewmember participation, and on-board controls required for Spacelab operations are outlined. Missions for a space platform for studying the atmosphere/space interface are described.

Knott, K.↗
NASA NTRS1982

A solar flare X-ray polarimeter for the Space Shuttle

An instrument has recently been built and tested which is designed to measure the polarization of the hard (5-30 keV) X-ray emission from solar flares, and thereby to investigate the energy release mechanism and constrain flare models. In particular, these measurements will help to determine whether hard X-ray bursts are produced by nonthermal or by thermal electrons. The polarimeter makes use of the angular dependence of Thomson scattering from targets of metallic lithium. It has an energy resolution of a few keV, a time resolution of 5 s, and sufficient sensitivity to measure polarization levels (3 sigma) of a few percent in about 10 s for a moderate strength solar flare. The instrumental polarization has been directly measured and found to be within the design goal of approximately 1%. This polarimeter is scheduled to be flown as part of the OSS-1 pallet on an early Space Shuttle mission.

Lemen, J. R.↗
NASA NTRS1982

NASA-ESA Spacelab systems and programs; Proceedings of the Seminar, Washington, DC, April 23, 24, 1981

Topics discussed include the development status of the Space Shuttle and Spacelab, with attention to Spacelab subsystem performance capabilities and Shuttle-Spacelab flight operations; Spacelab data management and software for science applications, ESA and Space Shuttle pointing systems, and the Space Shuttle's Office of Space and Terrestrial Applications (OSTA)-1 payload. Also covered are the lessons learned from the first Spacelab mission, the pallet-only mode verification flight of the second Spacelab mission, the objectives of the Spacelab mission D1, its role in the German space program, and its implementation, the impact of Spacelab on space-based life sciences research, the high resolution, large area modular reflector array X-ray telescope to be used by Spacelab, and Space Shuttle contamination effects on UV coronagraphic observations.

Moore, J. W.↗
NASA NTRS1981

Moisture sounding at millimeter wavelengths /94/183 GHz/ at high altitudes

A moisture sounding radiometer at millimeter wavelengths has been developed for high altitude measurements onboard NASA's WB-57F aircraft. Three channels about the 183.3 GHz water vapor line permit measurement of the atmospheric water vapor profile. A single window channel at 94 GHz provides correction for clouds over the ocean and for surface emissivity variations over land. The instrument is an imaging radiometer operating under microprocessor control throughout each data flight. The system is contained within two packages integrated into the WB-57F pallet. A ground support system was used to perform a quick-look analysis of the data collected immediately following each flight.

Gagliano, J. A.↗
NASA NTRS1983

Alternate thermal control coolant fluid investigation for the NASA Space Transportation System

Although Freon 21 has been assumed to be the coolant fluid for both the Space Shuttle Orbiter's primary heat rejection system and Spacelab's pallet heat transport loop, the fluid's supplier has considered stopping its production. This fact, together with the recent determination that maximum allowable toxicity levels must be reduced by a factor of 100, has prompted NASA's present investigation of a Freon 21 replacement which would provide comparable heat transport/rejection capability without requiring the redesign of existing hardware. Systems performance was analytically evaluated for many fluids, together with tests establishing material compatibility with alternate fluids and the character of any synergistic effects. Test results have indicated that Freon 114 is a viable alternative for some of the systems in question.

Hueter, U.↗
NASA NTRS1982

Studies of beam plasma interactions in a space simulation chamber using prototype Space Shuttle instruments

In March, 1981, electron beam experiments were conducted in a large space simulation chamber using equipment destined to be flown aboard NASA's Office of Space Science-1 pallet (OSS-1). Two major flight experiments were involved. They include the Vehicle Charging and Potential (VCAP) experiment and the Plasma Diagnostics Package (PDP). Apparatus connected with VCAP included a Fast Pulse Electron Gun (FPEG), and a Charge and Current Probe (CCP). A preliminary view is provided of the results obtained when the electron emissions were held steady over relatively long periods of time such that steady state conditions could be obtained with respect to the electron beam interaction with the neutral gases and plasma of the vacuum chamber. Of particular interest was the plasma instability feature known as the Beam Plasma Discharge. For the present experiments the FPEG was used in a dc mode with a range of currents of 2 to 80 mA at a beam energy of 970 eV. Attention is given to the emissions of VLF and HF noise associated with the dc beam.

Banks, P. M.↗
NASA NTRS1983

Image motion compensation for the OSS-3/7 telescopes

The three telescope for the NASA Office of Space Science (OSS) Missions 3/7 will be clustered on the Instrument Point System (IPS). The IPS is to be mounted on a Spacelab pallet in the space shuttle orbiter. The three telescopes include the Ultraviolet Imaging Telescope (UIT), the Hopkins Ultraviolet Telescope (HUT), and the Wisconsin Ultraviolet Photopolarimetry Experiment (WUPPE). All three instruments have the ability to view from earth orbit stellar objects which are fainter than those which can be seen with ground-based telescopes. An Image Motion Compensation (IMC) system will be required for the appropriate conduct of the observations. The OSS-3/7 pointing problem is discussed, and a cost effective IMC system is proposed.

Shelton, H.L.↗
NASA NTRS1984

41-B tenth Space Shuttle mission

The manned maneuvering unit, two untethered ""spacewalks'', EVA timeline, shuttle pallet satellite, payloads (Palapa-B2, Westar 6), and a rehearsal rendezvous are discussed.

Source record↗
NASA NTRS1984

Photovoltaic concentrator pointing dynamics and plasma interaction study

The objectives of this experiment are to use the Space Technology Experiments Platform (STEP) system to demonstrate the viability of concentrator photovoltaic arrays by: (1) configuring a deployable mast on the STEP pallet with concentrator mass models and some active photovoltaic modules; (2) measuring the array pointing dynamics under normal rotation as well as disturbance conditions; (3) performing an array plasma interaction experiment to determine the steady-state plasma losses under various voltage conditions; and (4) providing active distributed control of the support truss to determine the improvement in dynamic response. Experiment approach and test control and instrumentation are described.

Stern, T. G.↗
NASA NTRS1984

A deployable structure and solar array controls experiment for STEP

A candidate configuration for a controls experiment on the Space Technology Experiments Platform (STEP) is described. The elements of the experiment are the mast, the solar array, and an articulation module between the two. The characteristic dimensions are very compatible for integration on a pallet such a STEP's proposed configuration. The controls' objective would be the measurement of orbiter interaction as well as the system identification of the appendages. The flight experiment configuration would also provide a test bed for various active vibration controls concepts. The instrumentation being considered would measure accelerations, strains, displacements, and temperatures. The deployable mast has eight elements defining a structural bay. Uniaxial measurements would be required to define loads at a cross section of the structure. Displacements due to thermal distortion of the mast and the local state of the solar concentrator may be measured by an optical ranging technique from the orbiter aft flight deck.

Nishimoto, T. S.↗
NASA NTRS1981

The development of a high-capacity instrument module heat transport system, appendixes

Data sheets provide temperature requirements for 82 individual instruments that are under development or planned for grouping on a space platform or pallet. The scientific objectives of these instrument packages are related to solar physics, space plasma physics, astronomy, high energy astrophysics, resources observations, environmental observations, materials processing, and life sciences. System specifications are given for a high capacity instrument module heat transport system to be used with future payloads.

Source record↗
NASA NTRS1983

Launch processing for Spacelab 1

The final integration of Spacelab payloads with the Shuttle is described. Attention is given to launch processing planning, schedules, quality control, and problem reports and configuration maintenance. Also covered are the integration and checkout of individual and combined experiments, mounting the end cones, attachment of the transfer tunnel, and inclusion of an extra experiments pallet. The entire Spacelab module was subjected to a full systems simulation before deliverance to the Orbiter bay. Modular parts that were transferred from building-to-building were placed in sealed containers filled with a purged atmosphere during transport.

Mcbrayer, R. O.↗