Board of Directors ATK Officers Corporate Information Ronald R. Fogleman(2) Non-Executive Chairman of the Board, ATK. President, B Bar J Cattle and Consulting Company, a consulting firm. Mark W. DeYoung President and Chief Executive Officer Corporate Headquarters 1300 Wilson Boulevard, Suite 400 Arlington, Virginia 22209-2307 Telephone: 703-412-5960 E-mail: alliant.corporate@atk.com Roxanne J. Decyk(2,3) Former Executive Vice President of Global Government Affairs, Royal Dutch Shell plc. Mark W. DeYoung Director, President and Chief Executive Officer, ATK. Neal S. Cohen Executive Vice President and Chief Financial Officer Steven J. Cortese Senior Vice President Washington Operations Ronald P. Johnson Senior Vice President and President Sporting Group Martin C. Faga(2,3) Retired President and Chief Executive Officer of the MITRE Corporation, a not-for-profit systems engineering firm. Michael A. Kahn Senior Vice President and President Defense Group April H. Foley(1) Former United States Ambassador to Hungary. Jeff D. Kubacki Senior Vice President and Chief Information Officer (3) Tig H. Krekel Chairman and founding partner, Hudson Group, LLC, an advisory services firm. Douglas L. Maine(1,3) Former Chief Financial Officer, International Business Machines Corporation (IBM). Roman Martinez IV(1) Private investor. Former Managing Director, Lehman Brothers, an investment banking firm. Mark H. Ronald(1) Former Chairman of the Board, BAE Systems Inc., the wholly-owned U.S. subsidiary of BAE Systems plc, a British aerospace and defense company. William G. Van Dyke(1,3) Former Chairman and CEO, Donaldson Company, Inc., a provider of filtration systems and replacement parts. (1) Audit Committee (2) Nominating and Governance Committee (3) Personnel and Compensation Committee Blake E. Larson Senior Vice President and President Aerospace Group Deborah Moeschel Vice President and General Counsel Jay Tibbets Senior Vice President of Business Development Christine A. Wolf Senior Vice President Human Resources Annual Meeting of Stockholders The Annual Meeting of Stockholders will be held at Corporate Headquarters at 9:00 a.m. on August 7, 2012. Common Stock ATK common stock is listed on the New York Stock Exchange under ATK and in stock tables under AlliantTech. During FY12, approximately 66 million shares were traded. The closing stock price ranged from a low of $50.12 to a high of $75.97. Independent Registered Public Accounting Firm Deloitte & Touche LLP 50 South Sixth Street Suite 2800 Minneapolis, Minnesota 55402-1538 Transfer Agent and Registrar Stockholder inquiries should be directed to Transfer Agent/Registrar Computershare Shareowner Services 480 Washington Boulevard Jersey City, New Jersey 07310-1900 Telephone: 866-865-6322 Website: www.bnymellon.com/shareowner/ equityaccess Investor and Media Inquiries Inquiries from investors should be directed to Steve Wold, Vice President, Investor Relations and Corporate Finance Telephone: 952-351-3056 E-mail: Steve.Wold@ATK.com Inquiries from the media should be directed to Amanda Covington, Vice President, Corporate Communications Telephone: 703-412-3231 E-mail: Amanda.Covington@ATK.com Company Website The ATK website at www.ATK.com includes biographies of directors and executive officers, as well as information on the company’s corporate governance guidelines, and the charters of the committees of the Board of Directors. Forward-Looking Statements Certain information discussed in this 2012 Annual Report to Stockholders 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 these factors are: assumptions related to the profitability of current commercial aerospace structures programs; uncertainties related to the development of NASA’s new Space Launch System; demand for commercial and military ammunition; changes in governmental spending, budgetary policies, including the impacts of potential sequestration under the Budget Control Act of 2011, and product sourcing strategies; the company’s competitive environment; risks inherent in the development and manufacture of advanced technology; risks associated with the diversification into new markets; assumptions regarding the company’s long-term growth strategy; assumptions regarding the growth opportunities in international and commercial markets; increases in commodity costs, energy prices, and production costs; the terms and timing of awards and contracts; program performance; program terminations; changes in cost estimates related to relocation of facilities; the outcome of contingencies, including litigation and environmental remediation; actual pension asset returns and assumptions regarding future returns, discount rates and service costs; capital market volatility and corresponding assumptions related to the company’s shares outstanding; the availability of capital market financing; changes to accounting standards; changes in tax rules or pronouncements; economic conditions; and the company’s capital deployment strategy, including debt repayment, dividend payments, share repurchases, pension funding, mergers and acquisitions—including the related costs and any integration thereof. 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.