The newspaper SpaceNews has a good article today covering the fallout of NASA's (budget-driven) decision to mothball its Advanced Stirling Radioisotope Generator (ASRG) program, which would have been the next-generation Plutonium-238 power sources for spacecraft. Lockheed, the main contractor on the project, is shrinking its team and transferring the hardware to NASA's Glenn Research Center in Ohio:
Lockheed Martin Space Systems is shrinking a team of 140 down to 25 now that NASA has canceled work on the Advanced Stirling Radioisotope Generator (ASRG), a next-generation nuclear battery for planetary missions that cannot rely on solar power.
It will cost about $2 million and the effort of 10 employees to close out the program, Bob LeRoy, Lockheed’s director of East Coast Operations.
Since 2008, NASA has spent $272 million on ASRG, Len Dudzinski, program executive for radioisotope power systems at NASA headquarters here, wrote in a Jan. 15 email to SpaceNews.
Most of that went toward Lockheed’s contract, which was worth about $304 million when a stop-work order arrived in December. The contract includes a $45 million extension and a $25 million cost overrun, both of which occurred in 2012, LeRoy said. For its money, NASA got a final design for the ASRG, plus a partially completed qualification unit, which will be shipped to NASA’s Glenn Research Center near Cleveland later this year.
The rest of the article (which you should read) goes on to say that NASA's Planetary Science Division will save approximately $55 million per year, which, probably not coincidentally, is about the same as the cost of maintaining the Department of Energy's plutonium-238 infrastructure. Starting this year, NASA must now reimburse the DOE for all of its costs to create, store, and purify plutonium-238.
NASA's single option for plutonium power on spacecraft is the heavier, less-efficient, but more reliable MMRTG (multi-mission radioisotope thermoelectric generator), currently in use on the Curiosity rover and Cassini spacecraft.