The voyager spacecraft encountered all of the giant planets: voyagers 1 & 2 both flew past jupiter in march and july 1979, and encountered saturn in november 1980 and august 1981, with voyager 2…

This is a grant award from the National Aeronautics and Space Administration (NASA) to the University of Colorado Office of Contracts and Grants. The $298,260 grant will fund an effort to re-analyze and archive data from the Voyager spacecraft's Plasma Science (PLS) instrument, which measured ions and electrons during the Voyager missions' encounters with the giant planets from 1979 to 1989. The key objectives are to archive the complete magnetospheric data sets from Saturn, Uranus, and Neptune, provide analysis software, and validate the data and software through plasma modeling. This effort aims to further scientific understanding of the outer planets' magnetospheres using the Voyager data. The award has no set-aside designation and is not associated with a larger contract vehicle.

The voyager spacecraft encountered all of the giant planets: voyagers 1 & 2 both flew past jupiter in march and july 1979, and encountered saturn in november 1980 and august 1981, with voyager 2 moving on to uranus in january 1986 and ending with neptune in september 1989. The voyager plasma science (PLS) instrument comprised four faraday cups on each spacecraft which measured ions and electrons with energy-per-charge between 10 and 5950 volts. PI fran bagenal (CU) was supported by a jdap grant to RE-analyze the voyager PLS data at jupiter which resulted in 3 publications and archiving of the data and analysis routines. The plan is to archive the complete magnetospheric data sets from saturn, uranus and neptune including the measured currents in all modes of operation of the instrument, and pointing information. We also propose to provide a general magnetospheric analysis code and will archive a version of the most general analysis code, along with the data and pointing information. To validate and verify the code, this proposal plans to to fit a large number of spectra at saturn, using modern knowledge about the chemical composition based on cassini observations and physical chemistry models. IT will also revisit the data analysis for uranus and neptune to include spacecraft charging, non-maxwellian distribution functions, and the effects of electron feed through into the ION plasma measurements. The following will be archived at PDS: currents as a function of energy for every spectrum from the two voyager saturn encounters currents as a function of energy for every spectrum from the voyager 2 uranus and neptune encounters documented and validated software to read and analyze these spectra to produce plasma parameters complete plasma parameters from the saturn, uranus, and neptune encounters, derived from the spectral data using the above software.