Press Release

Pratt & Whitney Rocketdyne’s Space Shuttle Main Engines Power Final Flight to International Space Station

By SpaceRef Editor
July 11, 2011
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In an awesome display of technology and immense power that capped a 30-year legacy of boosting orbiters into space, three Space Shuttle Main Engines (SSMEs) today successfully powered the launch of Space Shuttle Atlantis on the program’s final flight to the International Space Station (ISS). The SSME is the only fully reusable high-performance rocket engine rated for human spaceflight, having delivered the majority of U.S. astronauts into space since its maiden Mission STS-1 on April 12, 1981. Pratt & Whitney Rocketdyne is the SSME prime integrator since program inception and is a United Technologies Corp. (NYSE:UTX) company.

“Pratt & Whitney Rocketdyne congratulates NASA and the countless men and women who dedicated their careers to this unprecedented program,” said Jim Maser, president, Pratt & Whitney Rocketdyne. “Their work helped carry astronauts into orbit to assemble a space station whose experiments not only advanced technologies on Earth, but forever enhanced our lives in health and medicine, transportation, public safety, computers, agriculture and environmental resources.”

“This is a proud day for us, knowing that our Space Shuttle Main Engines laid a strong foundation of safety, performance and innovation for continued space exploration,” said Jim Paulsen, SSME program manager, Pratt & Whitney Rocketdyne. “We are ready to support NASA’s journey and look forward to working with the agency in the next generation of space exploration.”

Atlantis launched from NASA’s Kennedy Space Center with a crew of four on Mission STS-135, which will carry the Raffaello multipurpose logistics module packed with supplies and spare parts for the station. The orbiter will also deliver a system that will be used to investigate the potential for robotically refueling existing spacecraft, and return a failed ammonia pump module to help NASA better understand the failure mechanism and improve pump designs for future systems.

The Space Shuttle Main Engines have boosted every shuttle launch since the program began in 1981, allowing astronauts from 14 different countries to travel to the ISS to conduct scientific experiments that forever changed life on earth. Scientific experiments conducted in space now commonplace include everything from smoke detectors and firefighter gear, to cardiac pacemakers and breast-cancer screening technology, to de-icing systems for airplanes. Also developed in space are nutrients now found in 90 percent of infant formulas sold worldwide.

The SSME is the world’s most reliable and highly tested large rocket engine ever built, and operates under extreme temperatures ranging from -423 degrees Fahrenheit to 6,000 degrees Fahrenheit -half the surface temperature of the sun. Even though the SSME weighs one-seventh as much as a locomotive engine, its high-pressure fuel pump alone delivers as much horsepower as 28 locomotives, while its high-pressure oxidizer pump delivers the equivalent horsepower for 11 more. If water instead of fuel were pumped by the three SSMEs, an average family-sized swimming pool could be drained in 25 seconds. The SSMEs have powered all 135 launches over the course of the shuttle program, totaling 57.6 hours of flight time and another 246.7 hours of accumulated ground testing.

During its distinguished 33-mission career, Atlantis helped deliver planetary probes to Venus and Jupiter, as well as components vital for the construction of the ISS. Atlantis has also flown on historic human flights, including the 100th U.S. manned space flight; the first U.S. shuttle-Russian Space Station Mir docking and joint on-orbit operations; and the first on-orbit change-out of shuttle crew. Atlantis was the first orbiter to introduce the most advanced versions of the SSME, the Block II configuration and advanced health management into operational service. After Atlantis returns from mission STS-135, it will be decommissioned and displayed at the Kennedy Space Center.

To hear directly from some of the people who have dedicated their lives to the success of the SSME program, go to:

Pratt & Whitney Rocketdyne, a part of Pratt & Whitney, is a preferred provider of high-value propulsion, power, energy and innovative system solutions used in a wide variety of government and commercial applications, including the main engines for the space shuttle, Atlas and Delta launch vehicles, missile defense systems and advanced hypersonic engines. Pratt & Whitney Rocketdyne is headquartered in Canoga Park, Calif., and has facilities in Huntsville, Ala.; Kennedy Space Center, Fla.; West Palm Beach, Fla.; and Stennis Space Center, Miss. For more information about Pratt & Whitney Rocketdyne, go to

Pratt & Whitney is a world leader in the design, manufacture and service of aircraft engines, space propulsion systems and industrial gas turbines. United Technologies, based in Hartford, Conn., is a diversified company providing high technology products and services to the global aerospace and commercial building industries.

SpaceRef staff editor.