With a roar and a rush of water vapor, the Space Shuttle’s Main Engines (SSME) reached a significant milestone on Wednesday Jan 21. The system surpassed one million seconds of successful testing and launch firings during a successful flight-acceptance test at NASA’s Stennis Space Center in Mississippi.
The engine that was tested is scheduled for use on STS-121, the mission following the Space Shuttle’s Return to Flight. The test ran for eight-and-a-half minutes, the length of time it takes the Space Shuttle to achieve orbit.
“This one millionth-second test is a testimony to the NASA and contractor team that developed, tested and continues to improve the SSME to safely take humans to low Earth orbit,” said NASA’s Miguel Rodriguez, director of the Propulsion Test Directorate at Stennis. “Personally, it is an honor to be part of this great program,” he added.
The one million seconds of performance have been accrued through more than 826,000 seconds in the test stand during development, certification and acceptance testing, and almost 174,000 seconds of flight time during 113 Space Shuttle missions.
The Main Engine that flies today has gone through major upgrades and is safer, stronger and more reliable than the one that flew on STS-1 in 1981. Reaching this milestone is a historic moment for the Space Shuttle Program,” said Michael Rudolphi, Space Shuttle Propulsion Manager.
Developed in the 1970s, the SSME is the world’s most sophisticated reusable rocket engine. Each is 14 feet long, weighs about 7,000 pounds and is seven-and-a-half feet in diameter at the end of its nozzle. It generates almost 400,000 pounds of thrust.
Rigorous testing is used to verify that an engine is ready to fly and is critical to any flight program. In 1998, engineers developed and tested a new main combustion chamber, which improved the SSMEs reliability by reducing operating temperature and pressures. A new high-pressure fuel turbo pump was also developed and implemented for its first flight in July 2001 on STS-104.
The Rocketdyne Propulsion and Power division of The Boeing Co. of Canoga Park, Calif., manufactures the SSMEs. Pratt and Whitney, a United Technologies Company, of West Palm Beach, Fla., builds the high-pressure turbo pumps and NASA’s Marshall Space Flight Center in Huntsville, Ala., manages the SSME project for the Space Shuttle Program.