Spacecraft require electrical energy. This energy must be available in the outer reaches of the solar system where sunlight is very faint. It must be available through lunar nights that last for 14 days, through long periods of dark and cold at the higher latitudes on Mars, and in high-radiation fields such as those around Jupiter. Radioisotope power systems (RPSs) are the only available power source that can operate unconstrained in these environments for the long periods of time needed to accomplish many missions, and plutonium-238 (238Pu) is the only practical isotope for fueling them.
Plutonium-238 does not occur in nature. The committee does not believe that there is any additional 238Pu (or any operational 238Pu production facilities) available anywhere in the world.The total amount of 238Pu available for NASA is fixed, and essentially all of it is already dedicated to support several pending missions—the Mars Science Laboratory, Discovery 12, the Outer Planets Flagship 1 (OPF 1), and (perhaps) a small number of additional missions with a very small demand for 238Pu. If the status quo persists, the United States will not be able to provide RPSs for any subsequent missions.
National Research Council. 2009. Radioisotope Power Systems: An Imperative for Maintaining U.S. Leadership in Space Exploration. Washington, DC: The National Academies Press.
Sign in to access your saved publications, downloads, and email
preferences.
Former MyNAP users: You'll need to reset your password on your first
login to MyAcademies. Click "Forgot password" below to receive a reset
link via email. Having trouble?
Visit our FAQ page
to contact support.
Members of the National Academy of Sciences, National Academy of
Engineering, or National Academy of Medicine should log in through their
respective Academy portals.
Register
Register
Thank You
Thank You
Thank you for creating a MyAcademies account!
Enjoy free access to thousands of National Academies' publications, a
10% discount off every purchase, and build your personal library.
Forgot Password
Forgot Password
Enter the email address for your MyAcademies (formerly MyNAP) account to
receive password reset instructions.
Reset Requested
Reset Requested
We sent password reset instructions to
your email
. Follow the link in that email to create a new password. Didn't receive
it? Check your spam folder or
contact us
for assistance.
We sent a verification link to your email. Please check your inbox (and
spam folder) and follow the link to verify your email address. If you
did not receive the email, you can request a new verification link below