Separate Meeting Held At The Same Times As Orbital's

The stockholders of Alliant Techsystems have approved the issuance of ATK common stock, par value $0.01 per share, to Orbital Sciences Corporation ("Orbital") stockholders in connection with the previously announced merger between ATK's Aerospace and Defense Groups and Orbital.

ATK and Orbital held separate, special stockholder meetings in conjunction with the proposed transaction. As previously announced, ATK intends to spin off its Sporting Group into Vista Outdoor Inc. ("Vista Outdoor") and immediately thereafter complete the merger. During Orbital's special stockholder meeting, Orbital stockholders voted to approve the merger.

Approximately 97 percent of the votes cast at ATK's special meeting of stockholders voted in favor of the issuance of shares, which represented approximately 77 percent of the total number of outstanding shares of ATK common stock as of December 16, 2014, the record date for the special meeting.

"We are very pleased with the resounding approval from our stockholders," said Mark DeYoung, ATK President and Chief Executive Officer (CEO) and future Chairman and CEO for Vista Outdoor. "The affirmation and confidence from our investors support the vision to create two strong, independent companies with leadership in their core markets. I want to thank our stockholders for their support of this vision and strategy. The favorable shareholder vote allows us to now move forward and finalize this transformational and value-creating transaction. We anticipate closing both the spin-off and the merger on February 9."

The share issuance proposal is described in detail in ATK's and Orbital's definitive joint proxy statement/prospectus, which was filed with the Securities and Exchange Commission on December 17, 2014.

FMI: www.atk.com