Reliability in long-life missions
Long life spacecraft design and reliability based on marine practices and advanced system technology project, considering grand tour outer planets mission
Draper, R. F.↗
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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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Investigation of space storable propellant acquisition devices. Volume 1 - Evaluation Final report, 24 Jul. 1969 - 15 Apr. 1970
Space storable propellant acquisition, pressurization, and tankage propulsion subsystems for Mars and Grand Tour missions
Source record↗
Investigation of space storable propellant acquisition devices. Volume 2 - Design and analysis Final report, Apr. - Aug. 1970
Space storable surface tension propellant acquisition system for Mars and Grand Tour missions
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A method of mapping Jupiter's gravitational potential by means of a proposed orbiting spacecraft
Jupiter gravitational potential mapping for Grand Tours spacecraft, discussing Jovian satellites effect on orbit and trajectory perturbations
Paul, C. K.↗
A Jupiter atmospheric entry mission
Jupiter atmospheric entry probe mission, discussing descent depths, atmospheric pressure and temperature effects, data return techniques and Grand Tour Missions
Carroll, P. C.↗
Onboard optical guidance instruments for outer planet spacecraft
Outer planets Grand Tour spacecraft onboard optical guidance instruments, discussing vidicon and image dissector systems designs
Stanton, R. H.↗
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.↗
The outer planets - What should the missions be
Mission analysis for multi-planet flyby and major satellites close encounter to determine solar system planetary evolution data, presenting Grand Tour trajectory parameters
Penzo, P. A.↗
Radioisotope thermoelectric generator optimization technique
Grand tour missions radioisotope thermoelectric generator power source, presenting optimization technique for hot thermocouple junction operation
Leonard, W. D.↗
Simplified interplanetary guidance using onboard optical measurements
Midcourse and planetary approach guidance by onboard optical measurements, noting application to earth-Mars trajectories and Grand Tour missions
Hamer, H. A.↗
Guidance and navigation requirements for unmanned flyby and swingby missions to the outer planets. Volume 1: Summary report
Unmanned spacecraft missions to the outer planets are of current interest to planetary scientists, and are being studied for the post 1970 time period. Flyby, entry and orbiter missions are all being considered using both direct and planetary swingby trajectory modes. The navigation and guidance requirements for a variety of missions to the outer planets and comets including both the three and four planet Grand Tours, are summarized.
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Behavioral, psychiatric, and sociological problems of long-duration space missions
In an attempt to isolate behavioral, psychiatric, and sociological problems expected on long- duration space missions, a literature search was conducted at the NASA Manned Spacecraft Center, Houston, Texas. Primary sources include short - term space flights, submarine tours, Antarctic expeditions, isolation-chamber tests, space-flight simulators, and hypodynamia studies. Various stressors are discussed including weightlessness and low sensory input; circadian rhythms (including sleep); confinement, isolation, and monotony; and purely psychiatric and sociological considerations. Important aspects of crew selection are also mentioned. An attempt is made to discuss these factors with regard to a prototype mission to Mars. However, it is concluded that more experimentation under actual space conditions are necessary before such a mission should be attempted.
Nick A Kanas↗
Simplified interplanetary guidance procedures using onboard optical measurements
Simplified guidance procedures have been developed which are based on preflight determination of the characteristics of perturbed trajectories. The results are devoted primarily to planetary approach guidance; however, some considerations for midcourse guidance are included. The methods are studied for an Earth-to-Mars trajectory but would be applicable to Grand Tour and other types of missions. Generally requiring only a single onboard optical angular measurement, the approach procedure predicts guidance corrections for the control of periapsis radius as well as orbital plane orientation. An error analysis has shown that the periapsis radius at Mars can be controlled to a 1 sigma accuracy of about 20 km if the guidance is performed 1/2 day before periapsis passage. If the guidance is performed at the Martian sphere of influence (2.2 days before periapsis), the error doubles because of the increased effect of measurement and maneuvering errors.
Hamer, H. A.↗
Power conditioning equipment for a thermoelectric outer planet spacecraft, volume 1, book 1
Equipment was designed to receive power from a radioisotope thermoelectric generator source, condition, distribute, and control this power for the spacecraft loads. The TOPS mission, aimed at a representative tour of the outer planets, would operate for an estimated 12 year period. Unique design characteristics required for the power conditioning equipment results from the long mission time and the need for autonomous on-board operations due to large communications distances and the associated time delays of ground initiated actions. The salient features of the selected power subsystem configuration are: (1) The PCE regulates the power from the radioisotope thermoelectric generator power source at 30 vdc by means of a quad-redundant shunt regulator; (2) 30 vdc power is used by certain loads, but is more generally inverted and distributed as square-wave ac power; (3) a protected bus is used to assure that power is always available to the control computer subsystem to permit corrective action to be initiated in response to fault conditions; and (4) various levels of redundancy are employed to provide high subsystem reliability.
Andrews, R. E.↗
Nuclear radiation interference and damage effects in charged particle experiments for extended space missions.
Demonstration that meaningful galactic and solar cosmic radiation measurements can be carried out on deep space missions. The radioisotopic thermoelectric generators (RTGs) which must be used as a source of power and perhaps of heat are a problem, but with proper separation from the experiments, with orientation, and with some shielding the damage effects can be reduced to an acceptable level. The Pioneer spacecraft are crucial in that they are targeted at the heart of Jupiter's radiation belts, and should supply the details of those belts. The subsequent Grand Tour opportunities can be selected for those periods which result in larger distances of closest approach to Jupiter if necessary.
Trainor, J. H.↗
Adaptive variable-length coding for efficient compression of spacecraft television data.
An adaptive variable length coding system is presented. Although developed primarily for the proposed Grand Tour missions, many features of this system clearly indicate a much wider applicability. Using sample to sample prediction, the coding system produces output rates within 0.25 bit/picture element (pixel) of the one-dimensional difference entropy for entropy values ranging from 0 to 8 bit/pixel. This is accomplished without the necessity of storing any code words. Performance improvements of 0.5 bit/pixel can be simply achieved by utilizing previous line correlation. A Basic Compressor, using concatenated codes, adapts to rapid changes in source statistics by automatically selecting one of three codes to use for each block of 21 pixels. The system adapts to less frequent, but more dramatic, changes in source statistics by adjusting the mode in which the Basic Compressor operates on a line-to-line basis. Furthermore, the compression system is independent of the quantization requirements of the pulse-code modulation system.
Rice, R. F.↗
On the writing of programming systems for spacecraft computers.
Consideration of the systems designed to generate programs for the increasingly complex digital computers being used on board unmanned deep-space probes. Such programming systems must accommodate the special-purpose features incorporated in the hardware. The use of higher-level language facilities in the programming system can significantly simplify the task. Computers for Mariner and for the Outer Planets Grand Tour are briefly described, as well as their programming systems. Aspects of the higher level languages are considered.
Mathur, F. P.↗
Viewing Phobos and Deimos for navigating Mariner 9.
A new on-board optical navigation data technique has been successfully demonstrated on Mariner 9. Science TV pictures of Phobos and Deimos against star fields were used in the real time navigation process to insert Mariner 9 into orbit about Mars. Real time and post flight evaluation results have shown that the satellite/star data taken by Mariner 9 was more accurate than preflight analysis indicated. In fact the orbital insertion phase of the mission could have been achieved using only optical data to determine encounter parameters. The use of a science TV camera to obtain this data was successfully demonstrated. Stars as dim as 9th magnitude were detected and measurement accuracies of 3 arc sec (1 sigma) were achieved. The success of the optical navigation techniques developed for Mariner 9 has placed a new class of demanding missions (e.g., multiple outer planet, satellite tour, etc) within realized navigation capability.
Duxbury, T. C.↗