Aeronautics and Space Report of the President FY 1995 Activities

Executive Summary

Department of Energy (DoE)

In FY 1995, DoE continued its work in the fabrication of three General Purpose Heat Sources-Radioisotope Thermoelectric Generators (GPHS-RTG) and 157 Radioisotope Heater Units (RHU) for NASA's upcoming Cassini mission to Saturn. DoE took delivery in 1995 of 4.2 kilograms of Russian-produced Plutonium-238 (Pu-238) to supplement its existing inventory; this material can be used to fuel smaller, more efficient spacecraft for future planetary exploration missions. DoE agreed to provide three Lightweight Radioisotope Heater Units (LWRHU) from its inventory (these are actually spares from the Galileo and Ulysses missions) for NASA's upcoming launch of the Mars Pathfinder spacecraft. For NASA's Pluto Express mission, DoE studied advanced converter technologies to provide high efficiency and lightweight power sources.

DoE staff also supported the Defense Nuclear Agency in managing the Topaz international program. Developed by the Russians, the Topaz is a nuclear reactor power source for spacecraft; unlike RTGs, it has moving parts like a ground nuclear powerplant. In conjunction with the Jet Propulsion Laboratory (JPL) and the Air Force, DoE explored the use of bimodal (power/propulsion) space reactor systems, especially in support of NASA's New Millennium spacecraft program. Finally, DoE's Sandia and Los Alamos National Laboratories continued to provide nuclear explosion sensors for integration onto DoD GPS and defense support program spacecraft.

Table of Contents Previous Forward

Curator: Lillian Gipson
Last Updated: September 5, 1996
For more information contact Steve Garber, NASA History Office,