ATK Solar Arrays, Thermal Technology, Diaphragm Tank and CoilABLE Boom Assist the Mars Phoenix Mission

Alliant Techsystems (NYSE:ATK) announces that the Ultraflex Solar Arrays deployed and now provide power to the Mars Phoenix Lander. This is the first flight for this unique solar array technology developed by ATK’s Goleta, California facility. Each Ultraflex array unfolded like an oriental fan into a circular shape 2.1 meters in diameter and will generate 770 watts of power from sunlight at the distance Earth is from the sun. Since Mars is approximately 1.5 times farther from the sun, the solar arrays will produce less than half the power possible on Earth.

Launched in August 2007, the Phoenix Mars Mission is the first in NASA’s Scout Program. Phoenix is designed to study the history of water and habitability potential in the Martian arctic’s ice-rich soil.

Also on board the Phoenix Lander is a CoilABLE boom which will deploy the Surface Stereo Imager camera. At release, strain energy stored in the stowed, coiled boom structure lifts the camera payload, weighing 4.5 times the weight of the boom, to a height about 27 inches above the lander deck. The deployed structure is a straight, three-sided truss capable of supporting the camera even if the lander is tilted on a 21 degree slope after landing. This boom design shares heritage with the boom which deployed a similar camera on the Mars Pathfinder lander in 1997.

In addition ATK produced both a Dual Bore Heat Pipe Assembly and a diaphragm tank to support the Phoenix Mars Lander Program. The Dual Bore Heat Pipe contained complex mechanical bending configurations and efficient heat transport and conductance capability that supported the heat removal from the Cruise Stage electronics to the Cruise Stage radiator. ATK is proud to supply so many critical pieces of this important NASA mission.

ATK is a premier aerospace and defense company with more than 17,000 employees in 21 states and $4.5 billion in revenue. News and information can be found on the Internet at www.atk.com .

Certain information discussed in this press release constitutes 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: changes in governmental spending, budgetary policies and product sourcing strategies; the company’s competitive environment; the terms and timing of awards and contracts; and economic conditions. ATK undertakes no obligation to update any forward-looking statements. For further information on factors that could impact ATK, and statements contained herein, please refer to ATK’s most recent Annual Report on Form 10-K and any subsequent quarterly reports on Form 10-Q and current reports on Form 8-K filed with the U.S. Securities and Exchange Commission.