Revenue for ATK Aerospace fell 6 percent to $302 million in the company’s 2012 third quarter as sales to NASA’s human spaceflight program continued to slump.

For the quarter ended Jan. 1, operating income at ATK Aerospace shot up to $34.8 million, parent company Alliant Techsystems (ATK) reported Feb. 2. That is a 45.6 percent increase compared with the 2011 quarter, when the unit booked a $25 million charge to account for lower sales and profits in “a commercial aerospace structures program.”

ATK’s quarterly net income fell 30 percent to $70.2 million. Earnings per share were $1.51, down from $2.09 in the 2011 quarter. Total revenue was $1.11 billion, a decline of 1.1 percent, the company said.

Also on Feb. 2, ATK said it will change its corporate structure so that it will have three operating units instead of four. Changes will be effective April 1.

ATK will fold its Missile Products and Armament Systems business into a single operating unit called Defense Group. Michael Kahn, president of the Missile Products group, will lead the new Defense Group.

Also as part of the reorganization, the Aerospace Systems group will be renamed as the Aerospace Group. Blake Larson, current head of Aerospace Systems, will lead the Aerospace Group.

ATK’s Security and Sporting group, meanwhile, will be rebranded as the Sporting Group. Ronald Johnson, now president of the Security and Sporting division, will lead the restyled Sporting Group.

Finally, ATK on Jan. 30 appointed Neal Cohen as its full-time chief financial officer, according to a Feb. 2 filing with the Securities and Exchange Commission. Cohen will start with ATK on Feb. 13. He most recently was president and chief operating officer of Laureate Education in Baltimore and previously was chief financial officer of Northwest Airlines and US Airways.

Cohen succeeds John Shroyer, who left ATK on Aug. 4.