U.S. House Science, Space, and Technology Committee Chairman Lamar Smith (R-Texas) today announced the release of a report by the Government Accountability Office (GAO) on U.S. production of plutonium 238 (Pu-238), a critical component of certain spacecraft power systems. GAO recommended that the Department of Energy (DOE), which oversees production of Pu-238, undertake steps to ensure production meets NASA’s needs for future missions.
Chairman Smith: “Assessing NASA’s needs and DOE’s capabilities is important for planning future missions. GAO issued three recommendations to DOE, all of which DOE indicated they would immediately implement. We will monitor DOE’s action and hope they will enable NASA to complete future missions.”
Space Subcommittee Chairman Brian Babin (R-Texas): “I appreciate GAO’s diligent report. As the recent Cassini mission’s success proves, radioisotope power systems are critical to advancing our nation’s exploration of space. Radioisotope production enables us to explore the outer planets and rove on other worlds. GAO’s report highlights many of the challenges facing NASA and DOE. I look forward to working with the administration to ensure that NASA’s future is just as bright as its past.”
Chairman Smith and Rep. Babin sent GAO a letter in October 2015 asking GAO to “examine NASA’s establishment of deep space power requirements and DOE’s plans for the resumption of Pu-238 production.” A copy of the letter can be found here.
The GAO report is available on the GAO website.
The Subcommittee on Space today held a hearing titled “Powering Exploration: An Update on Radioisotope Production and Lessons Learned from Cassini.” The purpose of the hearing is to evaluate NASA and DOE’s efforts to reconstitute the production of Pu-238. Pu-238 is used in radioisotope thermonuclear generators that provide electrical power for spacecraft that cannot use solar energy, but production ceased in the 1980s. With the recent end of NASA’s Cassini mission to Saturn, which used Pu-238 to enable its scientific discoveries, the hearing evaluated current efforts to reconstitute Pu-238 production and understand the science that it makes possible.
In 2015, the committee requested that GAO review NASA and DOE’s efforts to reconstitute domestic production of Pu-238. GAO released the results of its review at the hearing.
Key Takeaways of the GAO Report:

Future NASA missions may be at risk if Pu-238 production does not meet minimum projections, NASA opts to launch an additional mission using Pu-238 power supplies, or

Pu-238 is needed for national security or other non-NASA operations.

DOE has begun producing small quantities of Pu-238. The production identified key challenges that DOE is responding to.

DOE concurred with the report’s three recommendations:

First, DOE is in the process of developing a plan to more effectively measure progress with Pu-238 production. Second, DOE will work with NASA to “identify, assess, and develop plans to address known challenges” to the program. Third, as part of the plan to measure progress, DOE intends to track comprehensive programmatic risks in the program.

With the three recommendations, GAO believes that DOE will be better able to produce Pu-238 and manufacture the power supplies in accordance with NASA’s needs.