Minneapolis, September 23, 2004

ATK (NYSE: ATK) has completed its acquisition of the PSI Group following regulatory review from the Federal Trade Commission. The PSI Group is a leader in the design and manufacture of components for military and commercial space-based applications, including global positioning, navigation and communication satellites, satellite bus structures, struts, reflectors and deployable mast booms. The acquisition strengthens ATK's advanced space systems portfolio and positions it to capture emerging opportunities in spacecraft integration and satellite technology. The company expects to increase its content on missions while expanding into new advanced space technology roles. The $165 million purchase price represents approximately eight times PSI's anticipated full year earnings before income, taxes, depreciation and amortization (EBITDA). ATK is raising its FY05 earnings per share guidance to $3.90 to $4.00 per share. Previous guidance was $3.85 to $3.95 per share. In addition, the company is increasing its FY05 sales guidance to $2.75 billion from $2.7 billion. With planned pre-payments in excess of $100 million, ATK now expects FY05 year-end debt to be less than $1.15 billion. ATK is a $2.4 billion advanced weapon and space systems company employing 13,500 people in 23 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.

Tuesday, July 27, 2004
Alan Jones, ABLE Engineering Company
Contact: pajones@aec-able.com
Tel: (805) 685-2429

Goleta, CA - ABLE Engineering, Inc. (ABLE) will build 6 more GPS IIF Mod Solar Array Assemblies for The Boeing Company (Boeing) under a recently awarded contract. These mark the 4th through 9th solar arrays ABLE will build for Boeing to power GPS IIF Mod satellites. To support Boeing's recurring production needs, ABLE plans to build 12 flight units over the next 4 years. ABLE and Boeing have recently upgraded the solar array design in both size and photovolatic technology to provide over 2.6kW to power the enhanced capabilities of the current GPSIIF mission.

Similar ABLE deployable solar arrays have flown on board multiple commercial and government missions, including Indostar, Deep Space 1, BSAT-2A, 2B, and 2C, and Galaxy XII, XIV, and XV. ABLE designs and fabricates several solar array technologies and is a leading independent supplier of deployable space structures and solar arrays.

ABLE is a wholly-owned subsidiary of Pressure Systems, Inc (PSI). The PSI family of companies consist of three dedicated space components and subsystems suppliers, and includes PSI, the leading independent designer and manufacturer of titanium propellant and pressurant tanks for the space industry; PCI, the leading producer of advanced structural composite assemblies for spacecraft; and ABLE, the major supplier of space deployable structures, spacecraft mechanisms, and solar array systems. The principal owner of PSI, Windward Capital Partners, is a privately owned, New York based investment firm.

ATk