Orbital ATK is among the two private companies that presently hold a contract with the US space agency NASA for flying unmanned cargo missions to the International Space Station (ISS). The formation of the company took place with a merger of Orbital Sciences Corp. and Alliant Techsystems (ATK).

Specialized in launching tiny satellites, Orbital Sciences was best known for the Cygnus cargo spacecraft launch to the ISS, and ATK gained prominence by making solid rocket boosters for the space shuttles. Since the merger in February 2015, Orbital ATK has been working on defense systems, flight systems and space systems.

Under the $1.9 billion deal of Dulles, Va.-based Company with the space agency, it has to fly eight unmanned cargo missions to the ISS with the help of its Antares rocket and Cygnus capsule.

On October 28, 2014, pre-merger, Orbital Sciences faced a setback when its one spacecraft exploded immediately post launch, probably because of suspect Russian engines in Antares rocket of Orbital. In December last year, the flights resumed with a United Launch Alliance Atlas V rocket. A cargo delivery in March this year marked the final launch on a ULA rocket.

ATK's rocket boosters have been safely transporting the space shuttles to orbit, leaving aside the case of catastrophic failure in 1986 as a result of which seven astronauts on board space shuttle Challenger lost their lives. After the disaster, ATK brought design changes in the boosters.

ATK was among the contractors that were part of the NASA's Constellation program, aiming to transport astronauts to the moon and further. ATK has created the first stage of the Ares 1 rocket in which the astronauts would go up.

The program was envisioned under President George W. Bush and shortly after President Barack Obama took office the program got cancelled.