Motors Redesigned Following Challenger Disaster
Alliant Techsystems' Reusable Solid Rocket Motors (RSRM) passed
a major milestone this weekend, as they successfully powered NASA's
space shuttle Discovery and its crew during Sunday's launch. The
motors launched were the 100th flight set since the redesigned
RSRMs were first flown more than 20 years ago.
"The launch of the 100th flight set of NASA's twin boosters for
the Shuttle is another demonstration of ATK's commitment to safety
and mission success," said Mike Kahn, ATK Launch Systems Executive
Vice President and General Manager.
During Sunday's flight the boosters provided the main
thrust at liftoff, generating an equivalent of 15
million horsepower each and launching the shuttle to an altitude of
approximately 28 miles. After two minutes of flight, ATK's 16
Booster Separation Motors (BSMs) performed flawlessly. Four BSMs on
the forward skirt and four on the aft skirt of each booster fired
to jettison the boosters safely away from the shuttle orbiter and
external tank, enabling the rocket motors to parachute back down
through the Earth's atmosphere to be recovered and reused.
Over the past 20 years, ATK says both it and NASA have made
substantial investments in process automation, engineering
modeling, and inspection techniques that have enabled significant
improvements to flight safety margins, increased mission
reliability, and extended service life and reusability.
Current motors have had the benefit
of 27 full scale ground tests, including a successful five-segment
margin test performed in 2003, and numerous subscale and material
characterization tests that anchor complex analyses with hard
data.
"Transitioning the boosters and related critical skills to Ares
I will provide substantial benefit from all the experience and
progress gained over the years and enable significant risk
reduction to the program," said Kahn. "Our task is now to continue
our commitment to quality and success as we support the remaining
shuttle flights and prepare to launch Ares I-X and Ares I."
The RSRMs and BSMs will be used for the remainder of the Space
Shuttle Program with similar versions being used on NASA's Ares I,
the launch vehicle that will replace shuttle missions to the ISS as
well as conduct future lunar missions. ATK is the prime contractor
for the Ares I five-segment first stage.