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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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NASA NTRS1983

Plasma diagnostics package assessment of the STS-3 orbiter environment and systems for science

Primary objectives of the Plasma Diagnostics Package (PDP) on STS-3 as part of the OSS-1 'Pathfinder' payload were to measure aspects of the Orbiter's induced environment and to utilize Orbiter crew and subsystems in the conduct of scientific investigations. Instrumentation temperatures were found to be within predicted limits, payload bay pressure varied from ambient up to 0.001 torr with thruster firings, EMI levels were found to be below worst case estimates, and V x B motional potentials were observed to vary + or - 5 V with respect to Orbiter ground. These parameters exhibited orbit-period modulation. Payload bay plasma varied in density and composition from ambient to a rarefied mixture with Orbiter-produced H2O(+). Energetic electrons and ions with energies up to 10's of eV were observed occasionally. Primary and vernier thrusters induce a momentary perturbation to the electron density, to the pressure and to the electric field with low energy ions and electrons occasionally produced. With the PDP on the RMS, both automode and manual modes were used to seek sources of EMI, to characterize the Orbiter's plasma wake and to measure beam-plasma phenomena.

Shawhan, S. D.↗

NASA NTRS1983

Ultraviolet spectroscopy and the composition of cometary ice

A brief description of the nature of comets and of their interactions with their environments is given. Past observations are discussed, and particularly the data obtained for the West and Bradfield comets are compared. Far-ultraviolet observations are discussed in terms of the possibility of detecting the more volatile species such as H2O, CO2 and CO, which all have signatures in the ultraviolet spectral region. The comets observed by the International Ultraviolet Explorer are listed with the corresponding data. The space missions to be made in 1985-1986 are mentioned and these are the Giotto spacecraft mission, and the OSS-3 observatory that will fly aboard the Space Shuttle.

Feldman, P. D.↗

NASA NTRS1982

Approaches to environmental verification of STS free-flier and pallet payloads

This paper presents an overview of the environmental verification programs followed on an STS-launched free-flier payload, using the Tracking and Data Relay Satellite (TDRS) as an example, and a pallet payload, using the Office of Space Sciences-1 (OSS-1) as an example. Differences are assessed and rationale given as to why the differing programs were used on the two example payloads. It is concluded that the differences between the programs are due to inherent differences in the payload configuration, their respective mission performance objectives and their operational scenarios rather than to any generic distinctions that differentiate between a free-flier and a pallet payload.

Keegan, W. B.↗

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

Results from a 'small box' realtime molecular contamination monitor on STS-3

On the basis of early estimates of the Shuttle induced environment, Scialdone (1979) concluded that in the vicinity of the cargo, the cargo would have the largest influence on the environment. As a contamination control device, realtime monitors can indicate safe operational periods for sensitive attached payloads. It was, therefore, decided to develop the OSS-1/Contamination Monitor Package (CMP) experiment which was seen as a forerunner of an operational monitor. A description of the CMP is provided, taking into account four actively temperature controlled quartz crystal microbalances (TQCM). The TQCM temperatures could be varied from -60 C to +80 C. The sensor consisted of a matched pair of quartz crystals. The crystals were designated as a sensor and reference crystal. Results obtained during the STS-3 mission are discussed. These results show the feasibility and advantages of a small real-time contamination monitor.

Triolo, J.↗

NASA NTRS1984

Development of baseline random vibration environment criteria for Shuttle pallet payload subsystems

This paper presents a statistical evaluation of measured random vibration response data obtained from the Office of Space Science-1 (OSS-1) pallet payload. The data were measured during the acoustic test simulation (September 1980) and the ascent phase of the flight of STS-3, Orbiter 102 (launched from the Kennedy Space Center on March 22, 1982). Acoustic test efficiency factors are evaluated based on the Dynamic, Acoustic and Thermal Environments (DATE) instrumentation as the source of the measured vibration data. Test efficiency correction to test data is applied in the extrapolation of non-DATE acoustic test data to increase sample population size for improved statistical evaluation. For baseline criteria evaluation and development, data are grouped in accordance with the payload zone in which the component is mounted.

On, F. J.↗

NASA NTRS1983

Effects of chemical releases by the STS-3 Orbiter on the ionosphere

The Plasma Diagnostics Package, flown aboard STS-3 as part of the first Shuttle payload (OSS-1), recorded the effects of various chemical releases from the Orbiter. Changes in the plasma environment was observed during flash evaporator system releases, water dumps and maneuvering thruster operations. During flash evaporator operations, broadband Orbiter-generated electrostatic noise was enhanced and plasma density irregularities were observed to increase by 3 to 30 times with a spectrum which rose steeply and peaked below 6 Hz. In the case of water dumps, background electrostatic noise was enhanced at frequencies below about 3 kHz and suppressed at frequencies above 2 kHz. Thruster activity also stimulated electrostatic noise with a spectrum which peaked at approximately 0.5 kHz. In addition, ions with energies up to 1 keV were seen during some thruster events.

Pickett, J. S.↗

NASA NTRS1982

An experiment proposed and set up by the readers will be flying on board the Shuttle; these are the rules of the game; the experiments of others

The 400th round trip ticket to space via the space shuttle is booked in the name of an Italian journal. Students from that country are offered an opportunity to propose an experiment for NASA's Get Away Special program. The dimensional characteristics of the container, as specified by NASA, are given as well as limitations of weight, volume, diameter, and height for the experiment. The types of experiments in the OSS-1 payload and their operation are described.

Pazzano, P.↗

NASA NTRS1983

Development of baseline random vibration criteria for STS pallet payloads

On, F. J.↗

NASA NTRS1984

Measurements of electromagnetic interference on OV102 Columbia using the plasma diagnostics package

The third Space Shuttle mission's OSS-1 payload included 30 Hz-800 MHz and S-band receivers which assessed the intentional (transmitter) and unintentional (subsystem) EMI levels. It was noted that, at the pallet location, the UHF voice downlink transmitter field strengths did not exceed 0.1 V/m. At the remote manipulator system, the figure was 0.5 V/m. Below 300 kHz, the magnetic field noise was 30 dB pT + or - 20 dB, while the electric field noise was broadband and variable over at least 60 dB, depending on thruster firings and Orbiter attitude. This noise may have been generated by the Orbiter's interaction with the ambient plasma.

Shawhan, S. D.↗

NASA NTRS1985

Suprathermal plasma observed on STS-3 Mission by plasma diagnostics package

Artificially produced electron beams were used extensively during the past decade as a means of probing the magnetosphere, and more recently as a means of actively controlling spacecraft potential. Experimentation in these areas has proven valuable, yet at times confusing, due to the interaction of the electron beam with the ambient plasma. The OSS-1/STS-3 Mission in March 1982 provided a unique opportunity to study beam-plasma interactions at an altitude of 240 km. On board for this mission was a Fast Pulse Electron Generator (FPEG). Measurements made by the Plasma Diagnostics Package (PDP) while extended on the Orbiter RMS show modifications of the ion and electron energy distributions during electron beam injection. Observations made by charged particle detectors are discussed and related to measurements of Orbiter potential. Several of the PDP instruments, the joint PDP/FPEG experiment, and observations made during electron beam injection are described.

Paterson, W.↗

NASA NTRS1985

Research of advanced techniques for X-ray detectors and telescopes with applications to rockets and the LAMAR facility

A program for the development of high throughput instrumentation for X-ray astronomy based upon focusing optics is being carried out by the Smithsonian Astrophysical Observatory. The instrumentation is applicable to investigations requiring large area focusing optics for direct imaging or dispersive spectroscopy. The long range goals of this program are the development of telescopes and gratings for future major X-ray astronomy facilities, including additions to the LAMAR OSS-2/SHEAL experiment after the initial flights. Tests of the devices and their more immediate utilization in scientific investigations can be carried out with SPARTAN payloads deployed and retrieved by the Space Shuttle. However, the present backlog of approved SPARTAN missions is longer than the three-year duration of the program described in this program. Laboratory studies and breadboarding of instrumentation are discussed.

Gorenstein, P.↗

NASA NTRS1985

Effects of chemical releases by the STS 3 orbiter on the ionosphere

Pickett, J. S.↗

NASA NTRS1985

AE and DE mass spectrometer observations relevant to the shuttle glow

Recent work suggested that NO2 may be responsible for the observed continuum glow near surfaces of the space shuttle. The observations of atomic nitrogen (N) are reported at shuttle altitudes using mass spectrometers, giving special attention to the surface reactions of N relevant to the production of NO2 on spacecraft surfaces. Data from two semi-open sources mass spectrometers, the OSS instruments on the Atmosphere Explorer-C and -D satellites, and the closed source Neutral Atmospheric Composition Spectrometer (NACS) on the Dynamic Explorer-2 satellite are presented to show the similar behavior of NO in each case and the contrasting behavior of NO2. Although signals of NO and NO2 are highly dependent on surface temperature and surface composition, it appears that direct exposure of ion source surfaces to rammed gas is a necessary condition for the production of large amounts of NO2. Evidence that elevated surface temperatures can significantly reduce the production of NO2, likely by causing more rapid desorption of NO from these surfaces, is presented.

Engebretson, M. J.↗

NASA NTRS1984

Spacelab transitioning to Space Station

The availability of Shuttle and Spacelab makes it possible to fly a new class of scientific instruments. Thus, larger and heavier instruments can be employed, while the return of instruments after a mission provides an opportunity for instrument reconditioning and improvement in preparation for the next flight. In addition, the Shuttle provides a basic pointing capability with its Reaction Control System (RCS) which adjusts the attitude of the entire Shuttle in the desired direction. As part of Spacelab, the European Space Agency (ESA) developed an Instrument Pointing System (IPS). Early mission results are discussed, taking into account the first scientific payload carried on the Shuttle (OSTA-1), the OSS-1 payload, Spacelab 1, Spacelab 2, the Astro payload, Sunlab, and OSTA-3. Future missions are also considered, giving attention to the Solar Optical Telescope (SOT), the Shuttle Infrared Telescope Facility (SIRTF), and the Pinhole Occulter Facility (POF). It is pointed out that a number of the instruments being developed can be modified for operation on the Space Station.

Benson, R. H.↗

NASA NTRS1986

Development of the instruments for the Gamma Ray Observatory

The Gamma Ray Observatory (GRO) is to be launched in 1988 by the STS. The GRO will feature four very large instruments: the Oriented Scintillation Spectrometer Experiment (OSSE), the Imaging Compton Telescope (COMPTEL), the Energetic Gamma Ray Experiment Telescope (EGRET) and the Burst and Transient Source Experiment (BATSE). The instruments weigh from 900-1200 kg each, and required the development of specialized lifting and dolly devices to permit their assembly, manipulation and testing. The GRO is intended a{s a tool for studying discrete celestial objects such as black holes, neutron stars and other gamma-ray emitting objects, scanning for nucleosynthesis processes, mapping the Galaxy and other, high energy galaxies in terms of gamma rays, searching for cosmological effects and observing gamma ray bursts. The instruments will be sensitive from the upper end mof X-rya wavelengths to the highest energies possible. Details of the hardware and performance specifications of each of the instruments are discussed.

Madden, J. J.↗

NASA NTRS1986

A review of the findings of the plasma diagnostic package and associated laboratory experiments: Implications of large body/plasma interactions for future space technology

The discoveries and experiments of the Plasma Diagnostic Package (PDP) on the OSS 1 and Spacelab 2 missions are reviewed, these results are compared with those of other space and laboratory experiments, and the implications for the understanding of large body interactions in a low Earth orbit (LEO) plasma environment are discussed. First a brief review of the PDP investigation, its instrumentation and experiments is presented. Next a summary of PDP results along with a comparison of those results with similar space or laboratory experiments is given. Last of all the implications of these results in terms of understanding fundamental physical processes that take place with large bodies in LEO is discussed and experiments to deal with these vital questions are suggested.

Murphy, Gerald B.↗

NASA NTRS1988

A prototype combinatorial scheduler for space-borne observational instruments

A prototype scheduler has been developed for observations to be carried out by the NASA Gamma Ray Observatory. The purpose of the scheduling system is to provide an automated method to determine optimized schedules conforming to all scheduling guidelines. Strategies used in creating COMPTEL/EGRET schedules and in scheduling OSSE targets are examined. It is concluded that the hybrid scheduler creates optimal schedules, or very nearly optimal schedules, and reduces the estimated scheduling time by 18 or 19 orders of magnitude, from about 10 to the 14th years to as few as 561 seconds.

Gilstrap, Lewey O.↗