National Aeronautics and Space Administration

Office of the Administrator

Washington, DC 20546-0001

April 29, 2008

The Honorable Samuel W. Bodman

Secretary of Energy

Washington, DC 20585

Dear Mr. Secretary:

NASA requires the Department of Energy (DOE) to maintain the Radioisotope Power System (RPS) related facilities in an operational readiness status with the capability to provide NASA with current and future fueled RPS assemblies. As required by the National Space Policy of 2006 and the Atomic Energy Act of 1954 (as amended), the Atomic Energy Commission is “… the exclusive owner of all production facilities …” for special nuclear materials and as such we must emphasize that DOE must “… maintain the capability and infrastructure to develop and furnish nuclear power systems for use in United States Government Space systems …” NASA will pay for the special nuclear material used for our missions, but we are prohibited from directly funding production facilities or infrastructure required when the DOE has an appropriation for the same.

All NASA missions are subject to budget authority and Agency priorities. Likewise, NASA missions considering RPS must go through the National Environmental Policy Act review. However, for DOE planning purposes, NASA provides the following projected mission requirements:

Projected NASA Science Missions

Approved Missions

Projected Launch Year

Power Req’m (We)

Pu238 Usage (kg)1

Mars Science Lab




Outer Planets Flagship 1





 The Mars Science Lab and the Outer Planet Flagship I are designed to use the Multi Mission Radioisotope Thermoelectric Generator technology. The rest of the missions assume the use of Advanced Stirling Radioisotope Generator technology, significantly reducing the quantity of Pu238 required to meet the power requirement.

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