DESIGN MODIFICATIONS FOR INCREASING THE BOM AND EOM POWER OUTPUT AND REDUCING THE SIZE AND MASS OF RTG FOR THE PLUTO MISSION

A companion paper analyzed the effect on source modules for three specific fuel options, and compared the predicted power output with JPL's latest goals for the Pluto Fast Flyby (PFF) mission. The results showed that a 5-module RTG cannot fully meet JPL's goals with any of the available fuels; and that a 6-module RTG more than meets those goals with Russian fuel, almost meets them with U.S. (Cassini-type) fuel, but still falls far short of meeting them with the depleted fuel from the aged (1982) Galileo spare RTG. The inadequacy of the aged fuel was disappointing,because heat source modules made from it already exist, and their use in PFF could result in substantial cost savings. The present paper describes additional analyses which showed that a six-module RTG with the aged fuel can meet JPL's stipulated power margin with a relatively simple design modification, that a second design modification makes it possible to recover all of the mass and size penalty for going from five to six heat source modules, and that a third modification could raise the EOM power margin to 16%. There are four copies in the file. Cross Reference ESD Files FSC-ESD-217-94-531 (CID #8572)