Coursing accurately to the giant outer planets and their moons
Course correction requirements for ballistic grand tours and outer planet missions, considering trajectory disturbances by random nongravitational forces
Hamilton, T. W.↗
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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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A comparison of passage conditions at the outer planets for several flyby trajectory modes
Jupiter swingbys and multiplanet Jupiter swingby trajectory modes for outer planet missions, comparing in terms of passage conditions
Norman, S. M.↗
Thermionic reactor systems for electric propulsion
Thermionic reactor electric spacecraft propulsion system for unmanned outer planets missions, investigating voltage and radiator temperature effects on weight
Mondt, J. F.↗
Challenges in developing an approach guidance instrument for the outer planets
Onboard approach guidance instrument for Grand Tour to outer planets missions reducing fuel for corrective maneuvers by estimating trajectories
Stanton, R. H.↗
Performance testing and evaluation of a high temperature silicon germanium thermoelectric generator
Performance tests of high temperature silicon- germanium alloy thermoelectric generator for outer planet mission spacecraft
Stapfer, G.↗
The design of a source to simulate the gamma-ray spectrum emitted by a radioisotope thermoelectric generator
A simulated source was designed to duplicate the gamma spectrum of a uniform cylindrical 2200-watt Pu02 radioisotope thermoelectric generator containing 81% Pu-238 and 1.2 ppm Pu-236. Gamma rays from the decay of Pu-238, Am-241, Pu-239, and the 0-18(alpha,n)Ne-21 reaction were catalogued in broad energy groups. Two 46- and one 22-mc Th-228 sources provided simulation at various times in the life of the fuel capsule up to 18 years, which covers the time span of an outer planet mission. Emission from Th-228 represents the overwhelming contribution of the gamma spectrum after the first few years. The sources, in the form of 13-inch rods, were placed in a concentric hole in a cylinder of depleted uranium, which provided shielding equivalent to the self-shielding of the fuel capsule. The thickness of the U-238 cylinder (0.55cm) was determined by Monte Carlo calculations to insure that the spectrum emerging from the simulated source matched that of the fuel capsule.
Reier, M.↗
Jupiter trapped radiation belts
Previously developed models for trapped electron radiation belts and trapped proton radiation belts in the Jovian magnetosphere are described. The spatial distribution of flux and the L shell dependence of the characteristic energy are displayed for both models. Based on these models, the fluence accumulated by a Jupiter flyby spacecraft is given in terms of the equivalent 3-MeV fluence for electrons and the equivalent 20-MeV proton fluence. Finally, some impacts of these fluences on outer planet missions are described.
Beck, A. J., Jr.↗
Conclusion
A set of models was established for the Jupiter electron and proton trapped radiation belt which could be used in the determination of outer planets mission spacecraft design requirements. Two models each for the electron and proton components evolved: a nominal or best estimate model, and an upper limit model. The models are described by presenting the assumptions that were agreed to be then best basis for the models at this time, and then describing the models which were structured in the time available. The discussion which took place at the final session is also presented.
Beck, A. J., Jr.↗
Outer planet satellite ephemeris development.
Discussion of the possible effectiveness of an earth-based ephemeris development program for the outer planet natural satellites. Technologies for obtaining and reducing photographic plates are available and new satellite theories needed for data processing are being developed. It is shown that satellite ephemeris accuracies could be reduced to hundreds of km by the end of the 1970s. An earth-based program would have great benefits to future outer planet missions requiring this level of accuracy.
Duxbury, T. C.↗
Development and investigation of particle detectors in support of outer planet definition studies
Research is reported in support of the definition phase of the Outer Planets Missions. The definitions studies are discussed along with the investigations of the triple-grooved solid-state detectors.
Vogt, R. E.↗
A foldable 4.27 meter (14 foot) spacecraft antenna
The problems and solutions associated with the design, fabrication, and testing of a large, lightweight, radial-rib, folding, spacecraft antenna reflector are discussed. The antenna reflector was designed as a highly efficient communications system for outer-planet missions extending as far as approximately 59.839 x 10 to the 11th power meters (40 astronomical units) from the sun. The methods used to obtain a lightweight precision rib surface, the evaluation and fabrication of the metallic reflector mesh surface, and the surface-evaluation techniques used on the assembled antenna reflector are included.
Starkey, D. J.↗
Planetary quarantine. Space research and technology
The impact of satisfying satellite quarantine constraints on outer planet missions and spacecraft design are studied by considering the effects of planetary radiation belts, solar wind radiation, and space vacuum on microorganism survival. Post launch recontamination studies evaluate the effects of mission environments on particle distributions on spacecraft surfaces and effective cleaning and decontamination techniques.
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Planetary quarantine: Space research and technology
The impact of satisfying satellite quarantine constraints on current outer planet mission and spacecraft designs is considered. Tools required to perform trajectory and navigation analyses for determining satellite impact probabilities are developed.
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Atmospheric entry probes for outer planet exploration. Outer planet entry probe technical summary
The use of unmanned space probes for investigating the conditions existing on and around the outer planets of the solar system is discussed. The subjects included in the report are: (1) the design of a common entry probe for outer planet missions, (2) the significant trades related to the development of a common probe design, (3) the impact of bus selection on probe design, (4) the impact of probe requirements on bus modifications, and (5) the key technology elements recommended for advanced development. Drawings and illustrations of typical probes are included to show the components and systems used in the space probes.
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Planetary quarantine: Space research and technology
The impact of satisfying satellite quarantine constraints on current outer planet mission and spacecraft designs is considered. Tools required to perform trajectory and navigation analyses for determining satellite impact probabilities are developed.
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Outer planet Pioneer imaging communications system study
The effects of different types of imaging data compression on the elements of the Pioneer end-to-end data system were studied for three imaging transmission methods. These were: no data compression, moderate data compression, and the advanced imaging communications system. It is concluded that: (1) the value of data compression is inversely related to the downlink telemetry bit rate; (2) the rolling characteristics of the spacecraft limit the selection of data compression ratios; and (3) data compression might be used to perform acceptable outer planet mission at reduced downlink telemetry bit rates.
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Design of the Mariner Jupiter/Saturn 1977 telemetry system
In 1977 NASA will launch two spacecraft to perform scientific investigations of the Jupiter and Saturn planetary systems. The science payload includes a total of ten instruments to support both the interplanetary-cruise and planetary-encounter phases. These will be the first launches of a new generation of Mariner-class spacecraft designed for outer-planet missions. The telemetry-system design for these missions was especially challenging because of extreme communication ranges (1.5 billion km), high data-rate requirements (up to 115.2 kbit/sec), and more stringent data-quality requirements than previous Mariner missions. The present paper discusses the evolution and design of the Mariner Jupiter/Saturn 1977 telemetry system and presents the performance anticipated therefrom.
Wood, G. E.↗
Planetary quarantine, supporting research and technology
The impact of satisfying satellite quarantine on current outer planet mission and spacecraft designs was determined and the tools required to perform trajectory and navigation analyses for determining satellite impact probabilities were developed.
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