Cygnus CRS Orb-5, also known as Orbital Sciences CRS Flight 5, is the sixth planned flight of the Orbital Sciences'unmanned resupply spacecraftCygnus, its fifth flight to the International Space Station. Orbital and NASA jointly developed a new space transportation system to provide commercial cargo resupply services to the International Space Station (ISS). Under the Commercial Orbital Transportation System (COTS) program, Orbital designed and built Antares™, a medium-class launch vehicle; Cygnus™, an advanced maneuvering spacecraft, and a Pressurized Cargo Module which is provided by Orbital's industrial partner Thales Alenia Space. The COTS demonstration mission was successfully conducted in September 2013, and Orbital commenced operational ISS cargo missions under the Commercial Resupply Service (CRS) program with two missions in 2014.
Orbital will fulfill its commitment to deliver cargo to the ISS by the end of 2016. The company has contracted with United Launch Alliance for an Atlas V launch of Cygnus in late 2015 from Cape Canaveral, FL, with an option for a second Atlas V launch in 2016 if needed. The Antares propulsion system will be upgraded with newly-built RD-181 first stage engines to provide greater payload performance and increased reliability. The company has targeted Antares-launched CRS missions for the first, second and fourth quarters of 2016. This particular mission is known as Orb-5.
The design, manufacture and test of Antares occurs at Orbital locations in Dulles, VA and Chandler, AZ, with vehicle assembly and testing at its launch site at the Wallops Flight Facility on Virginia's Eastern Shore. Production and integration of Cygnus spacecraft is performed in Dulles, VA. The Cygnus service module is mated with the pressurized cargo module at the launch site, and mission operations are conducted from control centers in Dulles and Houston.
This is the fifth of eight flights by Orbital Sciences under the Commercial Resupply Services contract with NASA. This will be the third flight of the Castor 30XL second stage, and the second flight of the Enhanced sized Cygnus PCM. The mission is expected to launch in the summer of 2016.
Because of the explosion in the orb-3 mission. The Antares rocket has been replaced with the Atlas V while Orbital develops a new main propulsion system for their Antares rocket, which is expected to fly again starting in the first quarter of 2016.