Orbital ATK

A merger of Orbital Sciences Corporation and the defense and aerospace divisions of Alliant Techsystems (ATK) was announced on April 29, 2014.

The two companies had collaborated on several previous projects, including the use of 400 ATK rocket motors in Orbital's launch vehicles.

[9] Based in Chandler, Arizona,[4] the Flight Systems Group includes the Pegasus, Minotaur, and Antares launch vehicles as well as solid-propulsion and aerostructures programs.

[2] The company also operates a Lockheed L-1011 TriStar wide body jetliner, which is named Stargazer and is used to air launch Pegasus rockets carrying payloads into space.

The division also produces fuzing and warheads for both tactical missiles and munitions; precision metal and composite structures for medium and large-caliber ammunition, military aircraft, ground vehicles, and missile systems; load, assembly, and pack (LAP) of medium caliber munitions; and propellants and powders for the canister and commercial markets.

Antares rocket launches the Orb-2 mission.
A GEM 40 solid rocket motor being prepared for integration with a Delta II launch vehicle
The spacecraft Cygnus transporting cargo to the ISS on behalf of NASA .