ATK – Mayflower Team Selected for Navy Guided Extended Range Munitions Contract

Minneapolis, MN – May 11, 2004 – ATK’s (Alliant Techsystems, NYSE: ATK) Ballistic Trajectory Extended Range Munition (BTERM) II, an extension of the earlier Autonomous Naval Support Round (ANSR), captured the highly competitive award for development of the Navy five-inch Extended Range Munition (ERM). With a value of $30 million, the contract calls for ATK to perform a 16-month demonstration of an innovative extended range, low cost, gun launched projectile capable of operation in the Mk 45 Mod 4 and Mod 2 naval gun systems.

ATK’s teammates on ERM are The C.S. Draper Laboratory, Cambridge, Mass., Custom Analytical Engineering Systems (CAES), Cumberland, Md., and Mayflower Communications, Burlington, Mass.

ERM is ATK’s third advanced weapon development win in less than a year, following the earlier Advanced Anti-Radiation Guided Missile (AARGM) and Precision Guided Mortar Munition (PGMM) program awards. ATK’s fourth competitor for a precision systems prime award – the Mid Range Munition (MRM) – was successfully tested last month. That award decision is expected later this year.

ATK is a $2.3 billion advanced weapon and space systems company employing 13,200 people in 21 states. 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 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.