(Sen) - Orbital Sciences Corporation (Orbital, NYSE:ORB) is planning to roll out its Antares rocket Monday 1 October to the launchpad at NASA's Wallops Flight Facility in Virginia, in readiness for its first flight due to take place in the next couple of months.

The Antares flight is a test under NASA's Commercial Orbital Transportation Services (COTS) program under which the space agency is working with commercial companies to deliver cargo to the International Space Station (ISS).

Orbital, which operates a number of smaller launch vehicles, has been developing the Antares rocket and the Cygnus spacecraft that will one day be loaded with cargo for the space station. 

Before Orbital can start supplying the space station for real it must prove it is a safe and reliable transport system, which means it will have to pass phase 1 of COTS, development and demonstration. Phase 1 consists of two demonstartion flights - the first is for Antares to put the Cygnus freighter into orbit and for the cargo ship to return safetly to Earth. The second flight - currently set for December 2012 - will see Cygnus attempt to berth with the ISS in the same way SpaceX did with its Dragon spacecraft in May this year.

If the demonstration phase goes according to plan, Orbital will be cleared to begin delivering supplies to the space station under its Commercial Resupply Services (CRS) contract with NASA. Awarded in December 2008, the company has an agreement with NASA to resupply the orbiting complex 8 times. Orbital anticipates making its first cargo supply in 2013.

llustration of Orbital's Antares rocket on the launchpad at NASA Wallops. Credit: Orbital Sciences Corporation

The Antares launch vehicle can carry over 5 tonnes to Low Earth Orbit, while the Cygnus spacecraft will be capable of delivering 2.7 tonnes of pressurized cargo to the space station. Antares is a two stage vehicle with the launcher's design accommodating an optional third stage. In developing the rocket Orbital has drawn from its engineering experience and launch technologies that have been utilised successfully on its others launchers, Pegasus, Taurus and Minotaur.

NASA's COTS program is part of its strategy of using private companies to deliver cargo and astronauts to low-Earth orbit, in particular the International Space Station. COTS was created in 2006 and SpaceX was selected as its first partner under the program. Another company, Rocketplane-Kistler (RpK), was also selected in 2006 but the agreement with RpK was later terminated after it failed to complete financial and technical milestones. A second competition was held to select a new funded commercial partner which resulted in the selection of Orbital in February 2008.

Whilst Orbital prepares for its first demonstration flight, SpaceX's Falcon 9 rocket is scheduled to launch its Dragon cargo ship on October 7 to fulfil the first of 12 resupply missions under its NASA contract.