Pu-powered space probes face uncertain future

Journal Article · Sat Oct 01 04:00:00 EDT 1994 · Nuclear News

OSTI ID:146812

When fragments of comet Shoemaker-Levy 9 crashed into the gas clouds of Jupiter in July, the only representatives of humankind with a good view were a trio of spacecraft, Voyager 2, Galileo, and Ulysses. Radioisotope thermoelectric generators (RTGs) supplied by the Department of Energy provided the power to run the observing instruments on these spacecraft, but now that source of power-and all deep-space missions-may be in jeopardy. Despite the fact that the recently passed congressional appropriations bill increased funding for the RTG program by nearly 20 percent, from $51 million in 1994 to $61 million in 1995, rumors persist that the program is in danger of being discontinued. Peter Ulrich, chief of the Flight Programs Branch of the Solar System Exploration Division of the Office of Space Science at NASA, was confident that the program would stay alive through NASA`s next mission. RTGs will be on board the Cassini spacecraft scheduled to blast off in 1997 for an exploration of Saturn and its rings and moons. RTG`s use the heat produced by the alpha decay of plutonium-238 to heat a thermocouple, which generates electricity. Cassini is designed to carry three RTGs, producing a total of 750 W of electricity initially, decreasing to about 600 W by the time it reaches Saturn seven years after launch. The RTGs on Cassini will carry a total of about 70 lb of plutonium oxide. RTGs have no moving parts. They are simple, rugged, and reliable. According to Ulrich, {open_quotes}It`s really a very well-matched power source for something like a remote mission.{close_quotes} The political situation is less clear, though. {open_quotes}What I hear unofficially is funding looks dime,{close_quotes} said the DOE spokesperson, {open_quotes}and the lights are being turned off for these missions.{close_quotes} If that happens, the lights will go out on NASA`s deep-space missions to other parts of our solar system.

• OSTI ID: 146812
• Journal Information: Nuclear News, Journal Name: Nuclear News Journal Issue: 13 Vol. 37; ISSN NUNWA8; ISSN 0029-5574
• Country of Publication: United States
• Language: English

Related Subjects

07 ISOTOPE AND RADIATION SOURCES
30 DIRECT ENERGY CONVERSION
66 PHYSICS
AVAILABILITY
FINANCING
NESDPS Office of Nuclear Energy Space and Defense Power Systems
PLANNING
PLUTONIUM 238
POLITICAL ASPECTS
RADIOISOTOPE BATTERIES
SPACE FLIGHT
SPACECRAFT POWER SUPPLIES
THERMOELECTRIC GENERATORS