ATK Alliant Techsystems Inc. (now known as Northrop Grumman Innovation Systems) was an American aerospace, defense, and sporting goods company that was based in Arlington, Virginia. The company was founded in 1990 and was known for its work in the development and production of a wide range of products, including missiles, space systems, military and law enforcement equipment, and sporting goods.
ATK was known for its work in the development of advanced technologies, including propulsion systems, composite materials, and energetic materials. The company was also involved in the production of a number of high-profile products, including the Solid Rocket Boosters used on the Space Shuttle, the Mars rover Curiosity's descent stage, and the Orbital Sciences Corporation's Antares rocket.
In 2015, ATK merged with Orbital Sciences Corporation to form Orbital ATK, which was later acquired by Northrop Grumman in 2018 and rebranded as Northrop Grumman Innovation Systems.