NASA Successfully Test Fires Reusable Solid Rocket Motor

Test Evaluated Possible Performance Changes As Motor Ages

BBSNews 2008-05-02 -- NASA's Space Shuttle Program on Thursday successfully conducted a test firing of a space shuttle reusable solid rocket motor in Utah.

The test firing of Flight Verification Motor 2 evaluated possible performance changes as motors age. Space shuttle solid rocket motors are certified for flight for five years from their date of manufacture. At more than seven years of age, the four-segment motor tested Thursday is the oldest ever fired. The test further substantiates the certification that was established by NASA at the beginning of the shuttle program.

The test also provided important information for continued launches of the shuttle and development of the Ares I rocket, a key component of NASA's Constellation Program that will launch the Orion crew vehicle on missions to the moon.

The test measured external sound, or acoustics, to help define motor-generated external loads for Ares I. This valuable data will assist in the final design of the launch structure for Ares I rockets by engineers from NASA and ATK Launch Systems Group of Promontory, Utah.

Preliminary indications are that all test objectives were met. After final test data are analyzed, results for each objective will be published later this year.

"This test is an example of the aggressive testing program NASA pursues to assure flight safety," said David Beaman, manager of the Reusable Solid Rocket Booster Project office at NASA's Marshall Space Flight Center in Huntsville, Ala. "It also allows us to gather information on how motors with different ages perform."

The test provided a unique opportunity to compare performance data from two motors of different ages to validate midlife and full-life certification of their components. The segments tested Thursday were originally stacked at NASA's Kennedy Space Center in Florida in 2002 and returned to Utah in 2004. As a result of this test, engineers will better understand the effects of aging and exposure to different climates for extended periods of time.

Each space shuttle launch requires the power of two reusable solid rocket booster motors to lift the 4.5-million-pound shuttle vehicle. They burn for approximately 123 seconds and generate an average thrust of 2.6 million pounds. In Thursday's test, the motor generated 3.3 million pounds maximum thrust for two minutes, which is the same time each reusable solid rocket motor burns during a space shuttle launch.

The space shuttle reusable solid rocket motor is the largest ever to fly. It is the only solid rocket motor rated for human flight and the first designed for reuse. Two motors provide 90 percent of the thrust needed to launch the space shuttle.

The Reusable Solid Rocket Booster Project Office manages the tests. ATK Launch Systems Group, a unit of Alliant Techsystems Inc., manufactures space shuttle solid rocket motors.

More information about the Space Shuttle Program is available online.

More information about Constellation Program is also available online.