ATK to Provide at Least Nine Orion Motor Flight Sets – Options Could Enhance Total Contract Value
ATK Motors Support Missile Defense and Access to Space Missions

Alliant Techsystems (NYSE: ATK) has received a $49 million contract from Orbital Sciences Corporation (NYSE: ORB) to provide at least nine flight sets of Orion solid rocket motors. If options in the contract are exercised, the total value would increase. Orion motors are used on a variety of launch vehicles including Ground Based Missile Defense’s Orbital Boost Vehicle, as well as Minotaur, Pegasus and Taurus(R) launch vehicles.

The flight set motors range in size from 38 to 50 inches in diameter, and four to 33 feet in length. Each flight set consists of a minimum of three stages. Work under the contract will be performed by ATK at its facility in Salt Lake City, Utah. Deliveries are expected to be complete by 2011.

ATK’s Orion motors have a 100 percent mission success rate. They first flew in 1990 on a Pegasus(R) launch vehicle. In 2007, ATK delivered its 100th flight set.

“The proven performance and versatility of the family of Orion motors helps ensure mission success for critical programs that aid in scientific research and the defense of this country,” said Bill Condas, Vice President, ATK Strategic and Defense Systems.”

ATK is a premier aerospace and defense company with more than 17,000 employees in 21 states and approximately $4.6 billion in revenue. News and information can be found on the Internet at http://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: assumptions related to the future use of redesigned booster separation motors; 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.