ATK Successfully Conducts First Five-Segment Space Shuttle Motor Test

ATK (Alliant Techsystems)
yesterday successfully conducted the first static test firing of a
five-segment Space Shuttle reusable solid rocket motor (RSRM).

The test conducted by ATK Thiokol Propulsion, Promontory, Utah, was part
of an ongoing safety program to verify materials and manufacturing processes,
by ground testing motors with specific test objectives. This five-segment
motor, also considered a margin test motor, pushed various features of the
motor to its limits so engineers could validate the safety margins of the
four-segment motor currently used to launch Space Shuttles. The static firing
was also a test designed to demonstrate the ability of the five-segment motor
to perform at thrust levels in excess of 3.6 million pounds, approximately 10
percent greater than the four-segment motor.

“This test demonstrated ATK’s unique ability and expertise in the design
and production of the RSRM,” said Jeff Foote, group vice president, Aerospace.
“It is yet another visible commitment by NASA and ATK to ensure the highest
quality safety standards and mission success for future Space Shuttle
flights.”

Foote said that in addition to validating safety margins by over-testing
many RSRM attributes, the static firing also demonstrated the capability of
the five-segment motor to increase Space Shuttle payload capacity by 23,000
pounds, or enable a safe abort to orbit in the event of loss of thrust from
the main engines.

The five-segment motor generated an average thrust of 3.1 million pounds
and burned for approximately 128 seconds. The current four-segment
configuration generates an average 2.6 million pounds of thrust and burns for
approximately 123 seconds. The new motor measures 12 feet in diameter and is
153.5 feet long – 27.5 feet longer than the four-segment motor.

The static test allowed ATK to verify and validate numerous performance
characteristics, processes, materials, components, and design changes that
were incorporated into the five-segment RSRM. The test had 67 objectives and
employed 633 instrumentation channels to collect data for evaluation.
Preliminary results indicate that the motor met or exceeded all objectives.

The Space Shuttle RSRM is the largest solid rocket motor ever flown and
the first designed for reuse. The reusability of the RSRM case and nozzle
hardware is an important cost-saving factor for the nation’s space program.
Each Space Shuttle launch currently requires the boost of two RSRMs. By the
time the twin RSRMs have completed their task, the Space Shuttle orbiter has
reached an altitude of 24 nautical miles and is traveling at a speed in excess
of 3,000 miles per hour.

ATK Thiokol Propulsion is the world’s leading supplier of solid-propellant
rocket motors. Products manufactured by the company include propulsion systems
for the Delta, Pegasus®, Taurus®, Athena, Atlas, H-IIA, and Titan IV B
expendable space launch vehicles, NASA’s Space Shuttle, the Trident II Fleet
Ballistic Missile and the Minuteman III Intercontinental Ballistic Missile,
and ground-based missile defense interceptors.

ATK is a $2.2 billion aerospace and defense company with strong positions
in propulsion, composite structures, munitions, precision capabilities, and
civil and sporting ammunition. The company, which is headquartered in Edina,
Minn., employs approximately 12,200 people and has three business groups:
Precision Systems, Aerospace, and Ammunition and Related Products. ATK news
and information can be found on the Internet at www.atk.com .