X0306 4 2015-02-09 1 0000820736 ORBITAL SCIENCES CORP /DE/ ORB 0001045863 THOMPSON JAMES R JR C/O ORBITAL SCIENCES CORPORATION 45101 WARP DRIVE DULLES VA 20166 1 0 0 0 Common Stock 2015-02-09 4 D 0 281078 D 0 D Common Stock 2015-02-09 4 D 0 1385 D 0 I By Spouse Represents 277,748 shares of common stock disposed of pursuant to the Transaction Agreement among Alliant Techsystems, Inc. (renamed Orbital ATK, Inc.) ("Orbital ATK"), Vista Merger Sub Inc., Vista Outdoor Inc. (formerly known as Vista SpinCo Inc.) and Orbital Sciences Corporation ("Orbital") (the "Transaction Agreement"), pursuant to which each share of Orbital common stock was converted into 0.449 shares of Orbital ATK common stock and cash payable in lieu of fractional shares and 3,330 Restricted Stock Units disposed of pursuant to the Transaction Agreement whereby each Restricted Stock Unit of Orbital was converted into 0.449 Restricted Stock Units of Orbital ATK with the same vesting schedule, resulting in 124,708 shares of Orbital ATK common stock and 1,495 Restricted Stock Units of Orbital ATK, each at a market value of $63.94 based on the opening price per share of Orbital ATK common stock on the first trading day following the Merger. Represents 1,385 shares of common stock disposed of pursuant to the Transaction Agreement, pursuant to which each share of Orbital common stock was converted into 0.449 shares of Orbital ATK common stock and cash payable in lieu of fractional shares of Orbital ATK common stock, resulting in 621 shares of Orbital ATK common stock at market value of $63.94 per share based on the opening price per share of Orbital ATK common stock on the first day of trading following the Merger. /s/ James S. Black II, Attorney-in-Fact 2015-02-11