Astronomers push for more Pu-238 funding

Last month, NASA officials offered a bit of good news about plans to restart production of plutonium-238 (Pu-238), the isotope used in radioisotope thermoelectric generators (RTGs) that power some NASA deep space missions, including the recently-launched Mars Science Laboratory. In a hearing about the future of NASA’s planetary exploration program, NASA’s Jim Green said the agency was moving ahead with plans to restart production in cooperation with the Department of Energy (DOE), using $10 million allocated in the final FY12 appropriations bill for that purpose.

The original intent was to split the costs of Pu-238 production evenly between NASA and DOE, but Congress has failed to provide any money for that purpose in the separate DOE funding bill, saying that DOE funds should not be used for a program that primarily benefits NASA. This week, as House and Senate conferees work on an omnibus spending bill for various government agencies, including DOE, the American Astronomical Society (AAS) is making one final push to win DOE funding for Pu-238 production. In an “action alert” issued earlier this week, AAS asked its members to contact Sens. Dianne Feinstein (D-CA) and Lamar Alexander (R-TN), the chair and ranking member, respectively, of the energy and water appropriations subcommittee, and ask them to add Pu-238 funding. The AAS notes than even if production is restarted immediately, there will be a five-year gap in Pu-238 supplies. Any additional delay, the organization warns, “will push back the proposed planetary space missions that would require Pu-238. We cannot afford to delay production any longer.”