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Nunamaker, R. R.

Publications and source records attributed to Nunamaker, R. R..

10 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1975

Mission design of a Pioneer Jupiter Orbiter

The Mission analysis and design work performed in order to define a Pioneer mission to orbit Jupiter is described. This work arose from the interaction with a science advisory 'Mission Definition' team and led to the present mission concept. Building on the previous Jupiter Orbiter-Satellite Tour development at JPL a magnetospheric survey mission concept is developed. The geometric control of orbits which then provide extensive local time coverage of the Jovian system is analyzed and merged with the various science and program objectives. The result is a 'flower-orbit' mission design, yielding three large apoapse excursions at various local times and many interior orbits whose shape and orientation is under continual modification. This orbit design, together with a first orbit defined by delivery of an atmospheric probe, yields a mission of high scientific interest.

Friedman, L. D.↗
NASA NTRS1975

Analysis of a Jupiter swingby out-of-the-ecliptic mission

In addition to the outer planets, much interest is directed toward understanding the solar environment in which those planets and the earth have evolved. One means of obtaining some of the needed data is an out-of-the-ecliptic mission. Direct launch out of earth orbit does not allow acceptable solar latitudes to be achieved with existing launch vehicles. This paper presents the results of a study on using a Jupiter swingby to increase significantly the achievable solar latitudes. Latitudes above 60 deg can be achieved with an Atlas/Centaur/TE364-4 and a Pioneer-class spacecraft reduced in weight by about 50 kg. Jovian center-targeting contours have been generated, and a maximum achievable latitude has been determined as a function of launch year and spacecraft mass. Nominal trajectories are selected, and time histories of significant parameters are presented.

Manning, L. A.↗
NASA NTRS1975

Pioneer Jupiter Orbiter/Probe mission. I - Spacecraft system description

This paper discusses the Pioneer Jupiter Orbiter/Probe mission with emphasis on the orbiter spacecraft system. In this mission, the atmosphere of Jupiter will be investigated for physical and chemical structure by a probe which survives entry and transmits data while descending below the 10-bar level. The spacecraft deflects after probe separation to a nonimpacting approach trajectory, acts as a communications relay for data from the descending probe, and propulsively enters an orbit about Jupiter. As an orbiter, it explores the environment of Jupiter for three years, making in situ measurements of the particles and fields of the Jovian magnetosphere together with remote measurements (including images) of Jupiter and the Galilean satellites. The spacecraft system is logically based on the design of Pioneers 10 and 11 with modifications for these different mission requirements: antenna, receiver, and memory for the probe-spacecraft data link; a retropropulsion system for the high velocity-change requirements of orbit insertion; a data system consistent with the requirements of a line-scan imaging system; and an improved complement of radioisotope-thermoelectric-generator power sources to provide adequate power six years after launch.

Lassen, H. A.↗
NASA NTRS1975

Pioneer 10/11 mission results

The Pioneer 10/11 spacecraft and its scientific payload are described. The selected mission profiles and a summary of the scientific results are discussed. Results obtained during the traverse of the asteroid belt show that the particle concentration is less than had been theorized and does not present an appreciable hazard to future spacecraft passing through this previously unexplored region. Specific results from the Pioneer 10 mission and a 'first look' at the Pioneer 11 results from the 13 scientific instruments are presented. The particle and field phenomena measured within the Jovian radiation belt present a consistent picture which is, in general, an environment more severe and dynamic than that predicted by earth-based observations. Post-Jupiter trajectories for the Pioneer 10 and 11 missions are described.

Nunamaker, R. R.↗
NASA NTRS1973

Pioneer Venus mission plan for atmospheric probes and an orbiter.

The mission concept is described for a spin-stabilized spacecraft being designed to deliver an array of aerodynamic probes over the surface of Venus, and, on a second flight mission, to inject the spacecraft into a Venusian orbit. Large and Small Probes and the instrumented 'Bus' structure will enter the Venusian atmosphere and directly measure its characteristics. An orbiting configuration of the same basic Bus spacecraft will serve as a platform from which to examine the planetary environment, the outer atmosphere and its interaction with the solar wind, as well as surface topography. The orbital mission will extend over a complete revolution of the planet around the sun and around its own axis. Requirements for cost effectiveness and firm adherence within early cost projections are emphatic program guidelines which affect every major element of the mission plan and conceptual design.

Dyer, J. W.↗
NASA NTRS1970

Pioneer project - 1965-1970

Pioneer spacecraft flight missions, discussing interplanetary, solar-earth and deep space observations

Dickerson, L. W.↗