Alliant Techsystems’ (NYSE: ATK) Reusable Solid Rocket Motors (RSRMs) once again performed flawlessly as they ignited at 2:28 p.m. EST, launching the Space Shuttle Atlantis on its mission to resupply the International Space Station (ISS) and conduct the final crew rotation for the shuttle program.

Standing at 149 feet tall and 12 feet in diameter, the two solid rocket boosters each produced more than 15 million horsepower and 3.3 million pounds of maximum thrust as they safely launched the crew on their journey to the ISS. The cases from the two boosters for this mission have collectively flown on 60 previous shuttle missions.

After the flight, the RSRMs were jettisoned from the orbiter and external tank by ATK’s 16 Booster Separation Motors (BSMs). Each booster has eight BSMs: four on the forward skirt and four on the aft skirt. The separation motors propelled the RSRMs to a safe distance from the shuttle orbiter, enabling the spent boosters to parachute down through the Earth’s atmosphere where they splashed down into the ocean and were recovered for reuse.

“There is always a sense of pride as we demonstrate the reliability and performance of the solid rocket motors at every launch,” said Blake Larson, ATK Space Systems President. “We are now manufacturing the final motor for the shuttle program, which makes this a bittersweet time for us; we recognize this great program is coming to an end, but we know that Ares I will provide the same reliability with a great increase in crew safety.”

Utilizing data from a robust test program and from the recovered shuttle boosters after each flight has provided ATK and NASA with a wealth of information and understanding of the performance of human-rated solid rocket motors. This information enables the company to constantly improve its techniques and processes to increase the safety and mission reliability that will carry forward into the Ares I program. The shuttle’s four-segment rocket motor recently served another important role in the Ares I program when it successfully launched Ares I-X on October 28, providing important data to be used in finalizing the design of the Ares I launch vehicle.

“The success of Ares I-X directly correlates to the extensive knowledge and understanding we have gained over the life of the shuttle program,” said Mike Kahn, ATK Space Systems executive vice president. “As we continue ground and flight tests for the Ares I program, the heritage and reliability gained from the shuttle program will translate into the safest, most reliable launch vehicle ever flown.”

The remaining shuttle flights will be supported by ATK’s rocket motors, while the second Ares I five-segment first stage motor and updated BSM motors are being manufactured and prepared for testing. As the replacement for the space shuttle, the Ares vehicle will support missions to the ISS while enabling U.S. space exploration for decades to come. ATK is the prime contractor for the first stage.

ATK is a premier aerospace and defense company with more than 18,000 employees in 22 states, Puerto Rico and internationally, and revenues of approximately $4.8 billion. News and information can be found on the Internet at www.atk.com.