News Releases

ATK Receives $17.5 Million Contract for CASTOR 120® Motors

October 23, 2006

MINNEAPOLIS, Oct. 23 /PRNewswire-FirstCall/ — Alliant Techsystems (NYSE: ATK) has received a $17.5 million contract from Orbital Sciences Corporation (NYSE: ORB) for CASTOR 120 motors. The motors will be used on the Taurus XL launch vehicle and will support NASA’s Orbiting Carbon Observatory (OCO) and Glory earth science satellite missions scheduled for launch from Vandenberg Air Force Base, Calif. in 2008. ATK Launch Systems will perform the work at its Promontory, Utah, facility.

The CASTOR 120 is a medium-sized solid rocket motor that develops approximately 371,000-lbf average thrust during its 82-second burn time. The CASTOR 120 flew for the first time in 1997 as the first stage of an Athena I launch vehicle.

ATK is a $3.4 billion advanced weapon and space systems company employing approximately 15,000 people in 22 states. 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: 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.

  Media Contact:                        Investor Contact:

  George Torres                         Steve Wold
  Phone:  801-251-2819                  Phone:  952-351-3056
  E-mail:  george.torres@atk.com        E-mail:  steve.wold@atk.com

SOURCE: ATK

CONTACT: Media, George Torres, +1-801-251-2819, george.torres@atk.com ,
or Investors, Steve Wold, +1-952-351-3056, steve.wold@atk.com , both of ATK

Web site: http://www.atk.com/