WASHINGTON - NASA has signed a $975 million contract extension with Pratt and Whitney Rocketdyne Inc., of Canoga Park, Calif., to maintain the agency's fleet of space shuttle main engines until the orbiter is retired in 2010.

The contract began on April 1, 2006. It is scheduled to conclude Sept. 30, 2010. The $975 million contract extension brings the total value of the cost-plus-award/incentive fee contract to slightly more than $2.05 billion.

Pratt and Whitney Rocketdyne supports the Shuttle Propulsion Office at NASA's Marshall Space Flight Center in Huntsville, Ala.; the Space Shuttle Program Office at NASA's Johnson Space Center in Houston; and the Space Operations Mission Directorate at NASA Headquarters in Washington. The contract includes maintenance and refurbishment of existing shuttle main engines at NASA's Kennedy Space Center, Fla.

Each space shuttle is powered by three of the sophisticated engines, the world's only reusable rocket engines. During launch, each of the 7,750-pound engines burns liquid hydrogen and liquid oxygen, fed from the shuttle's external tank. Each engine generates approximately 400,000 pounds of thrust, which works with the shuttle's twin solid rocket boosters to power the spacecraft to orbit.

For more information about NASA's Space Shuttle Program, visit:

http://www.nasa.gov/shuttle