Mineralogical investigations of Mars.
Martian surface minerological study of present state and past processes from rock analyses by unmanned spacecraft instruments to test planetary models
Oconnor, J. T.↗
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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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Development and application of a system model for spacecraft sterilization Final report
Mathematical model for analyzing spacecraft sterilization requirements for planetary quarantine
Source record↗
Magnetometers for space research
Operational characteristics of spacecraft magnetomers for measuring planetary and interplanetary magnetic fields
Ness, N. F.↗
Simplified technique for estimating navigational accuracy of interplanetary spacecraft
Navigational accuracy of two way Doppler tracking of interplanetary spacecraft during heliocentric and planetary encounter trajectory phases
Bollman, W. E.↗
Thermal analysis of the 14-foot deployable parabolic antenna
Thermal analysis of deployable parabolic antenna for Outer Planetary Explorer program, discussing spacecraft spin and radioisotope thermoelectric generators effect
Kay, S.↗
Gas-powered reentry body erection mechanism
The design, analysis, testing, and flight of the supersonic planetary entry decelerator 2 spacecraft are described. The vehicle was launched in a folded condition and deployed to its required configuration following exit from the atmosphere. This concept was selected primarily because it allows utilization of existing launch vehicle systems in the most economical manner possible.
Muraca, R. J.↗
Guide to the use of Mariner images
Planetary imaging from unmanned spacecraft, almost exclusively done by digital systems, is examined. The Mars Mariner 9 television camera, representative of such systems, is considered. Each image consists of 700 lines, each containing 832 picture elements, or pixels. Each pixel contains nine binary bits of information capable of displaying 512 discrete brightness levels. Several problems inherent in television systems are discussed. These include nonuniform target response, residual images, noise, and blemishes. These defects can be removed to some extent by decalibration of the image. The final product is geometrically corrected for camera distortion and photometrically corrected. Several versions of the decalibrated images are available. The most generally useful are the geometrically corrected images with enhanced contrast. The Mariner 10 imaging of Mercury is briefly discussed.
Saunders, R. S.↗
The JPL orbit determination software system
The Jet Propulsion Laboratory (JPL) orbit determination software system is described. Consisting of a set of computer programs, this system has been developed at JPL for the primary purpose of determining the flight path of deep-space mission spacecraft in NASA's planetary program. Secondary uses include science studies in celestial mechanics and extraterrestrial atmospherics. Attention is given to such features as the capability for processing 30 data types from up to 15 tracking stations, and for precise navigation to natural satellites of outer planets. In addition, the system contains models for such conditions as mascons, atmospheric drag, attitude control, and finite motor burns, to provide for extensive solve-on capabilities.
Ekelund, J. E.↗
Computing Long-Term Orbital Motions
Drifts and lifetimes predicted. Long-term Orbit Predictor (LOP) is trajectory-propagation computer program used as analysis tool for studies of lifetimes of orbiting spacecraft. Used for any planetary orbiting missions. LOP written in FORTRAN 77.
Kwok, J. H.↗
Design considerations for the beamwaveguide retrofit of a ground antenna station
A primary requirement of the NASA Deep Space Network (DSN) is to provide for optimal reception of very low signal levels. This requirement necessitates optimizing the antenna gain to the total system operating noise level quotient. Low overall system noise levels of 16 to 20 K are achieved by using cryogenically cooled preamplifiers closely coupled with an appropriately balanced antenna gain/spillover design. Additionally, high-power transmitters (up to 400 kW CW) are required for spacecraft emergency command and planetary radar experiments. The frequency bands allocated for deep space telemetry are narrow bands near 2.1 and 2.3 GHz (Ka-band), 7.1 and 8.4 GHz (X-band), and 32 and 34.5 GHz (Ka-band). In addition, planned operations for the Search for Extraterrestrial Intelligence (SETI) program require continuous low-noise receive coverage over the 1 to 10 GHz band. To summarize, DSN antennas must operate efficiently with low receive noise and high-power uplink over the 1 to 35 GHz band.
Veruttipong, T.↗
Technological status and future challenges of deep space optical communication
An account is given of the concepts, techniques, and system design features that may be used to realize an optical communications link for future planetary missions. Such a spacecraft subsystem would encompass a 10-30 cm aperture optical telescope for both transmitting and receiving. Uplink from a laser, in the form of pulsed ranging signals or command information, will be extracted by a tracking detector; downlink data, as well as detected ranging pulses, will be properly formatted and used to modulate the downlink laser. The optical receiving station may be either on the ground or in earth orbit.
Lesh, James R.↗
Laboratory evaluation and application of microwave absorption properties under simulated conditions for planetary atmospheres
Radio absorptivity data for planetary atmospheres obtained from spacecraft radio occultation experiments and earth-based radio astronomical observations can be used to infer abundances of microwave absorbing atmospheric constituents in those atmospheres, as long as reliable information regarding the microwave absorbing properties of potential constituents is available. The key activity for this grant year has continued to be laboratory measurements of the microwave and millimeter-wave properties of the simulated atmospheres of the outer planets and their satellites. A Fabry-Perot spectrometer system capable of operation from 32 to 41 GHz was developed. Initially this spectrometer was used to complete laboratory measurements of the 7.5 to 9.3 mm absorption spectrum of ammonia. Laboratory measurements were begun at wavelengths near 3.2 mm, where a large number of observations of the emission from the outer planets were made. A description of this system is presented.
Steffes, Paul G.↗
Spectra of van der Waals complexes (dimers) with applications to planetary atmospheres
Spectral features observed in the atmosphere of Titan by the Voyager IR experiment have been attributed to weakly bound complexes of N2 and H2, dominant and minor constituents, respectively. The abundance of H2-N2 dimers there was computed. Current calculations include quantitative spectral line positions and intensities for N2-Ar and CO2-CO2 relating to Titan and Earth, and to Mars and Venus, respectively. This work suggests applications to spectra of planetary atmospheres obtained in spacecraft missions.
Fox, Kenneth↗
The importance of batteries in unmanned missions
The planetary program has historically used batteries to supply peak power needs for mission specific applications. Any time that additional power has been required in order to meet peak power demands or those applications where only limited amounts of power were required, batteries have always been used. Up until the mid to late 70's they have performed their task admirably. Recently, however, we have all become aware of the growing problem of developing reliable NiCd batteries for long mission and high cycle life applications. Here, the role rechargeable batteries will play for future planetary and earth observing spacecraft is discussed. In conclusion, NiCds have been and will continue to be the mainstay of the power system engineers tools for peak power production. Recent experience has tarnished its once sterling reputation. However, the industry has stood up to this challenge and implemented wide ranging plans to rectify the situation. These efforts should be applauded and supported as new designs and materials become available. In addition, project managers must become aware of their responsibility to test their batteries and insure quality and mission operating characteristics. Without this teamwork, the role of NiCds in the future will diminish, and other batteries, not as optimum for high performance applications (low mass and volume) will take their place.
Klein, John W.↗
Interagency telemetry arraying for Voyager-Neptune encounter
The reception capability of the Deep Space Network (DSN) has been improved over the years by increasing both the size and number of antennas at each complex to meet spacecraft-support requirements. However, even more aperture was required for the final planetary encounters of the Voyager 2 spacecraft. This need was met by arraying one radio astronomy observatory with the DSN complex in the United States and another with the complex in Australia. Following a review of augmentation for the Uranus encounter, both the preparation at the National Radio Astronomy (NRAO) Very Large Array (VLA) and the Neptune encounter results for the Parkes-Canberra and VLA-Goldstone arrays are presented.
Brown, D. W.↗
The Galileo Venus encounter
Galileo's instruments obtained a broad range of planetary measurements during the spacecraft's Venus encounter on February 10, 1990. The instrumentation brought to bear encompassed UV spectra, limb haze studies, and particles-and-fields experiments. These data, in conjunction with ground-based observations conducted during the encounter, have yielded accurate information on the Venus plasma environment, cloud patterns, and the possibility of interpreting certain impulsive events as lightning.
Johnson, Torrence V.↗
The mass of massive rover software
A planetary rover, like a spacecraft, must be fully self contained. Once launched, a rover can only receive information from its designers, and if solar powered, power from the Sun. As the distance from Earth increases, and the demands for power on the rover increase, there is a serious tradeoff between communication and computation. Both of these subsystems are very power hungry, and both can be the major driver of the rover's power subsystem, and therefore the minimum mass and size of the rover. This situation and software techniques that can be used to reduce the requirements on both communication and computation, allowing the overall robot mass to be greatly reduced, are discussed.
Miller, David P.↗
Development of a Space-Rated Proton Exchange Membrane Fuel Cell
Power systems for human spacecraft have historically included fuel cells due to the superior energy density they offer over battery systems depending on mission length and power consumption. As space exploration focuses on the evolution of reusable spacecraft and also considers planetary exploration power system requirements, fuel cells continue to be a factor in the potential system solutions.
Hoffman, William C., III↗