Space Exploration: Power Sources for Deep Space Probes

Pursuant to a congressional request, GAO reviewed the use of nuclear power systems for the Cassini spacecraft and other space missions, focusing on: (1) the processes the National Aeronautics and Space Administration (NASA) used to assess the safety and environmental risks associated with the Cassini mission; (2) NASA's efforts to consider the use of a non-nuclear power source for the Cassini mission; (3) the federal investment associated with the development of non-nuclear power sources for deep space missions; and (4) NASA's planned future nuclear-powered space missions.