ATK (Alliant Techsystems)
solid propulsion and composite technologies supported the
successful launch yesterday of an Orbital Sciences Corporation
air-launched Pegasus® XL rocket from Vandenberg Air Force Base, Calif. The
rocket carried the Scientific Satellite (SciSat-1) Atmospheric Chemistry
Experiment spacecraft into space for NASA and the Canadian Space Agency.

ATK’s Orion solid propulsion motors provided power for all three stages of
the air-launched vehicle. The motors, which have flown on all Pegasus rockets
since its first mission in 1990, are manufactured in Magna, Utah. The
composite payload fairing, filament-wound solid rocket motor cases, and the
interstage that form the Pegasus vehicle’s main structure were produced by ATK
in Clearfield, Utah, while the composite bus structure of the satellite
payload was fabricated at ATK’s San Diego facility.

“ATK’s significant contribution to commercial, military, and scientific
space exploration is a source of great pride to the company and we were
pleased with yet another successful launch of our proven propulsion and
composite structures technology,” said Jeff Foote, group vice president,
Aerospace.

Since its maiden flight in 1990, Orbital’s Pegasus rocket has conducted 35
missions and launched more than 70 satellites — becoming the world’s standard
for affordable and reliable small launch vehicles. The SciSat-1 mission was
the 21st consecutive successful launch of the Pegasus system.

Orbital’s L-1011 aircraft carries the rocket to approximately 40,000 feet
over the ocean, where it is released in a horizontal position before igniting
its first-stage Orion motor. The composite payload fairing separates
approximately 110 seconds into flight, following second-stage ignition.
Approximately ten minutes into the flight, the third-stage Orion motor
completes its burn, placing the satellite payload into orbit.

ATK is the world’s leading supplier of solid-propellant rocket motors.
Products include propulsion systems for the Delta, Pegasus, Taurus®, Atlas,
H-IIA, and Titan IV 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 has revolutionized the composites industry through 40 years of
innovation and manufacturing excellence. The company produces structures for
space launch vehicles, satellites, spacecraft, and commercial and military
aircraft.

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 12,000 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 .

Certain information discussed in this press release may constitute
forward-looking statements as defined in the Private Securities Litigation
Reform Act of 1995. Although ATK believes that the expectations reflected in
such forward-looking statements are based on reasonable assumptions, it can
give no assurance that its expectations will be achieved. Forward-looking
information is subject to certain risks, trends and uncertainties that could
cause actual results to differ materially from those projected. Among those
factors are: unforeseen delays in NASA’s Space Shuttle program, changes in
governmental spending and budgetary policies, economic conditions, equity
market returns, the company’s competitive environment, the timing of awards
and contracts, the outcome of contingencies, including litigation and
environmental remediation, program performance, and sales projections. ATK
undertakes no obligation to update any forward-looking statements. For
further information on factors that could impact ATK, and statements contained
herein, reference should be made to ATK’s filings with the Securities and
Exchange Commission, including quarterly reports on Form
10-Q, current reports on Form 8-K and annual reports on Form 10-K.