Successful test leads way for safer Shuttle solid rocket motor

Allard Beutel
Headquarters, Washington June 10, 2004
(Phone: 202/358-4769)

June Malone
Marshall Space Flight Center, Huntsville, Ala.
(Phone: 256/544-0034)

RELEASE: 04-190

SUCCESSFUL TEST LEADS WAY FOR SAFER SHUTTLE SOLID ROCKET
MOTOR

NASA's Space Shuttle program successfully fired a full-
scale Reusable Solid Rocket Motor today, testing
modifications that will enhance the safety of the Space
Shuttle.

A slightly different propellant grain was tested. The new
design improves flight safety by decreasing the risk of
cracks in the propellant during storage and transportation,
according to Jody Singer. Singer is manager of NASA's
Reusable Solid Rocket Motor Project, Space Shuttle Propulsion
Office, Marshall Space Flight Center, Huntsville, Ala.

"Even though the modification is only a slight change from
what we have flown on the Shuttle, it still requires a
rigorous certification and verification process that includes
testing," said Mike Rudolphi, manager of the Space Shuttle
Propulsion Office. "NASA has long adhered to the maxim, 'Test
what we fly; fly what we test,'" added Rudolphi. "This test
is one in a series of tests performed to ensure this
modification will perform as we expect," he said.

The propellant grain modification is one of 76 test
objectives. Twenty-four of the objectives allow the Project
Office to reevaluate materials, components and manufacturing
processes in use, such as nozzle bondlines, liner-to-housing
bondlines, internal insulation, pressure transducers, and
solvents.

The test will also provide information on a proposed safety
enhancement to the motor's nozzle. A new bolted assembly on
the nozzle's joint 5 is being tested for strength.

The full-scale stationary test was performed at ATK Thiokol
Propulsion Division, an Alliant Techsystems Inc., company in
Promontory, Utah. ATK Thiokol manufactures the Space
Shuttle's Reusable Solid Rocket Motor.

Static firings of flight support motors are part of the
ongoing verification of components, materials and
manufacturing processes required by the Space Shuttle
program. Flight support motors are tested annually to
evaluate, validate and qualify any proposed improvements or
changes to the motor. The two-minute test duration is the
same length of time that the motors perform during Space
Shuttle flights. The motor is one of the four Shuttle
propulsion elements.

Data from the test will be analyzed and the results for each
objective provided in a final report. The flight support
motor's metal case segments and nozzle components will be
refurbished for reuse.

This is the second test motor firing in less than a year for
the Reusable Solid Rocket Motor Office. A five-segment
engineering test motor demonstrated in October 2003 pushed
the motor to its limits so engineers could validate the
safety margins of the four-segment motor used to launch Space
Shuttles.

At 38.4 meters (126 feet) long and 3.6 meters (12 feet)
diameter, the Space Shuttle's Reusable Solid Rocket Motor is
the largest solid rocket motor ever flown and the first
designed for reuse. The motor has four 30-foot segments
filled with propellant. During liftoff, each motor generates
an average thrust of 1.2 million kilograms (2.6 million
pounds).

For information about NASA's work to return Space Shuttles to
safe flight on the Internet, visit:

http://www.nasa.gov/news/highlights/returntoflight.html


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Jacques :-)

www.spacepatches.info