ATK Receives New Sole-source Contract for HELLFIRE Rocket Motors

Minneapolis, December 20, 2005 – ATK (NYSE: ATK) has received a contract valued at nearly $3 million to manufacture rocket motors for the Lockheed Martin (NYSE: LMT) HELLFIRE® II missile, the first year of a proposed five-year agreement between ATK and Lockheed Martin.

The total value of the agreement, if all options are exercised, exceeds $20 million. Work will be performed in Rocket Center, West Virginia and Orlando, Florida.

The rocket motors are expected to satisfy the requirements of the U.S. services as well as allied nations. Production is underway, and deliveries will begin in 2006.

The sole-source supplier of the HELLFIRE II rocket motors, ATK has manufactured over 35,000 motors since production began in 1987. In addition, ATK manufactures the copper liner for the main shaped-charge warhead for the high-explosive anti-tank (HEAT) HELLFIRE, the AGM-114K, as well as the metal augmented charge (MAC) warhead for the AGM-114N, or “thermobaric” warhead, which is just starting production.

HELLFIRE can be launched from rotary-wing aircraft, unmanned aerial vehicles, ground-based tripods, high-mobility multipurpose wheeled vehicles (HUMVEEs) and boats. HELLFIRE is effective against a wide variety of targets, including tanks, ships, bunkers and buildings; and its precision-strike semi-active laser guidance minimizes collateral damage.

More than 1,000 HELLFIRE II rounds of all four versions (HEAT, MAC, blast fragmentation and millimeter-wave Longbow) have been fired successfully in Afghanistan and Iraq.

ATK is a $3.1 billion advanced weapon and space systems company employing 15,000 people in 23 states. News and information can be found on the Internet at www.atk.com.

Headquartered in Bethesda, MD, Lockheed Martin employs 135,000 people worldwide and is principally engaged in the research, design, development, manufacture and integration of advanced technology systems, products and services.

News and information can be found online at http://www.lockheedmartin.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 and budgetary policies, the company’s competitive environment, the timing of awards and contracts, 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.

Contact Information

Bryce Hallowell

ATK Corporate Communications

Alliant Techsystems Inc.

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