Antares (), known during early development as Taurus II, is an expendable launch system developed by Orbital Sciences Corporation (now part of Northrop Grumman) and the Yuzhnoye Design Bureau to launch the Cygnus spacecraft to the International Space Station as part of NASA's COTS and CRS programs. Able to launch payloads heavier than 8,000 kg (18,000 lb) into low Earth orbit, Antares is currently the largest rocket operated by Northrop Grumman. Antares launches from the Mid-Atlantic Regional Spaceport and made its inaugural flight on April 21, 2013.NASA awarded Orbital a Commercial Orbital Transportation Services (COTS) Space Act Agreement (SAA) in 2008 to demonstrate delivery of cargo to the International Space Station. For these COTS missions Orbital intends to use Antares to launch its Cygnus spacecraft. In addition, Antares will compete for small-to-medium missions. Originally designated the Taurus II, Orbital Sciences renamed the vehicle Antares, after the star of the same name, on December 12, 2011.

Out of 16 total launches, Antares has suffered one failure. During the fifth launch on October 28, 2014, the rocket failed catastrophically, and the vehicle and payload were destroyed. The rocket's first-stage engines were identified as the cause for the failure. A different engine was chosen for subsequent launches, and the rocket had a successful return to flight on October 17, 2016.