Antares, known during early development as Taurus II, is an expendable launch system developed by Orbital Sciences Corporation. Able to launch payloads heavier than 5,000 kg (11,000 lb) into low-Earth orbit, it made its inaugural flight on April 21, 2013.[4] Designed to launch the Cygnus spacecraft to the International Space Station as part of NASA's COTS and CRS programs, Antares is the largest rocket operated by Orbital Sciences.
NASA awarded to 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.[8] On December 12, 2011, Orbital Sciences renamed the launch vehicle "Antares" from the previous designation of Taurus II, after the star of the same name.[9]
Antares made four successful launches to orbit in its first five attempts. On October 28, 2014, an Antares rocket exploded just after liftoff, completely destroying the vehicle and badly damaging launch pad 0 at the Mid-Atlantic Regional Spaceport.
http://en.wikipedia.org/wiki/Antares_(rocket)