Paula Cleggett-Haleim
Headquarters, Washington, D.C.                                                                         
July 26, 1991
(Phone:  202/453-1547)

Joanne L. Johnson
Department of Energy, Washington, D.C.
(Phone:  202/586-5806)


RELEASE:  91-119

NASA AND DOE SIGN SPACE NUCLEAR POWER AGREEMENT


     NASA Administrator Richard H. Truly and Secretary of Energy 
James D. Watkins today signed an interagency agreement on 
cooperation in areas relating to space isotope power.

     Today's agreement updates an earlier pact dating back to 
1965.  The present accord provides an "umbrella" set of 
principles that delineates the authorities and responsibilities 
of NASA and DOE on the research, technology development, design, 
production, delivery, spacecraft integration and launch support 
for radioisotope power systems.  Supplemental agreements will be 
signed for each specific NASA mission at the assistant secretary 
and associate administrator level.

     NASA and DOE have cooperated extensively on space missions 
since the beginning of the U.S. space program.  For example, DOE 
provided nuclear power sources (radioisotope thermoelectric 
generators, or RTGs) for the Apollo Lunar Surface Experiment 
Packages and the Viking Mars landers.  RTGs use the natural decay 
of Pu-238 to produce heat which is transformed into electrical 
power through thermoelectric devices.  A typical modern RTG 
produces about 300 watts of electrical power and will operate 
unattended at this level for many years.  Some have operated for 
more than 14 years.

     Deep space missions such as the Pioneers 10 and 11, launched 
in 1972 and 1973, are still operating near the edge of our solar 
system.  The Voyager spacecraft, launched in 1977, is still 
operational due to its being powered by RTGs.  The recently 
launched Galileo and Ulysses also used RTGs.  A total of 17 NASA 
flights used nuclear power systems -- all with an unparalleled 
safety record.

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