Virginia based-Orbital Sciences has 3,600 employees and a 27-year track record in manufacturing satellites and ground and launch services, and providing engineering support. Its Pegasus launcher, dropped from a carrier aircraft, is the first winged vehicle to reach Mach 8 and has been used to launch small satellites since 1996. Orbital's Minotaur rockets have orbited 30 satellites from eight launches.

The first five-stage Minotaur V contract was signed recently with the US Air Force, to deliver a payload to lunar orbit in 2012.

Taurus II is designed to deliver up to 5,000kg (11,000lb) to low-Earth orbit. It uses Aerojet's version of the Russia's NK-33 liquid oxygen, kerosene engines fuelled by a Ukrainian-built core stage tank combined with an Alliant Techsystem's Castor 30 solid rocket motor upper stage. The Cygnus Advanced Manouvering Spacecraft can deliver 2,000kg in payload with its hypergolic fuelled service module and Thales Alenia Space-provided cargo module.

Orbital won $170 million from NASA after a recompetition last year of the Commercial Orbital Transportation Services (COTS) demonstration programme when Rocketplane Kistler's involvement ceased. Orbital's COTS proposal is based on a Taurus II rocket and Cygnus. In December 2008 Orbital won a $1.9 billion International Space Station resupply contract from NASA for eight flights from 2011 to 2015 and to dispose of waste.

Source: Flight International