Press Release

ATK Rocket Motors Launch Shuttle Discovery on Mission to International Space Station

By SpaceRef Editor
August 13, 2001
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ATK (Alliant Techsystems) said two reusable solid rocket
motors (RSRM) manufactured by its Aerospace Group helped launch NASA’s Space
Shuttle Discovery on a mission to the International Space Station from Cape
Canaveral Air Force Station, Fla., on Aug. 10.

Manufactured by ATK Thiokol Propulsion Company, Promontory, Utah, the
Space Shuttle RSRM is the largest solid rocket motor ever flown and the first
designed for reuse.

Paul Ross, senior group vice president, Aerospace, said the addition of
Thiokol Propulsion, which was acquired by ATK in April 2001, expands the
company’s solid rocket propulsion capabilities to encompass systems for
commercial, military, and civilian use.

“Our propulsion products range from boosters and staging motors for space
launch vehicles such as the Delta family, Pegasus®, Taurus®, Athena,
Atlas, H-IIA, and Titan IV B — to systems for key strategic programs like the
Trident II Fleet Ballistic Missile, Minuteman III, and the administration’s
national missile defense initiative,” said Ross.
“We also serve the
propulsion needs of the military, providing systems for Navy ballistic missile
defense programs and tactical missiles fired from aircraft and ships.
Rounding out our portfolio are the RSRMs for NASA’s Space Shuttle — the
cornerstone of America’s civilian space program.
All together, it’s a product
offering that makes ATK the aerospace industry’s leading supplier of
high-quality solid propulsion systems.”

Gerald Smith, president, ATK Thiokol Propulsion Company, said the
reusability of the Shuttle RSRM case is one of the most important cost-saving
factors in the nation’s Space Transportation System.

“Each RSRM case consists of 11 steel sections, each designed to perform
safely and predictably for up to 20 launches or static tests,” said Smith.
“Portions of the case used in the current mission (STS-105) were used as early
as the second Space Shuttle flight in November 1981, and as recently as STS-91
in July 1998.
All together, portions of the cases have flown on 40 Space
Shuttle missions and have been used in four static test firings.”

Other key facts about the Space Shuttle RSRM:

  • The RSRMs provide 71 percent of thrust at liftoff and during
    first-stage ascent.

  • From ignition to end of burn, each RSRM generates an average thrust of
    2.6 million pounds and burns for approximately 124 seconds.

  • Each motor is just over 126 feet long and 12 feet in diameter. The
    entire booster — including nose cap, frustum, and forward and aft
    skirts — is approximately 149 feet long.
    Of the motor’s total
    approximate weight of 1.25 million pounds, propellant accounts for
    approximately 1.1 million pounds.

  • By the time the 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.

  • With safety, quality, and reliability as their primary objectives, ATK
    Thiokol Propulsion Company engineers direct approximately 110,000
    quality control inspections on each RSRM flight set.

Highlighting the 13-day Discovery mission is the rotation of the
International Space Station crew, the third flight of an Italian-built
Multipurpose Logistics Module delivering additional scientific racks,
equipment, and supplies for the Space Station, and two space walks.
The
mission will involve three crews:
the four-member crew of Discovery, the
three members of the Expedition Three crew to be launched to the Space
Station, and the three members of the Expedition Two crew returning to Earth
aboard Discovery.

ATK is a $1.6 billion aerospace and defense company with leading positions
in propulsion, composite structures, munitions, and precision capabilities.
The company, which is headquartered in Hopkins, Minn., employs approximately
9,600 people and has two business segments:
Aerospace and Defense.
ATK news
and information can be found on the Internet at http://www.atk.com

SpaceRef staff editor.