The Cygnus service module for the OA-4 CRS mission. Photo: Orbital ATK.

[Via Satellite 10-16-2015] Orbital ATK has delivered the service module for its Cygnus spacecraft to NASA’s Kennedy Space Center for the next International Space Station (ISS) cargo mission, scheduled to launch on Thursday, Dec. 3. The Cygnus spacecraft will be assembled at Kennedy and launched aboard a United Launch Alliance (ULA) Atlas 5 rocket in lieu of Orbital ATK’s Antares, which is being refitted with RD-181 engines in place of the twin AJ-26s previously used.

The OA-4 Commercial Resupply Services (CRS) mission serves as the first flight of the enhanced variant of the Cygnus spacecraft, capable of delivering more than 7,700 pounds of cargo to astronauts on board the ISS. It is also the first mission to use Orbital ATK’s lightweight UltraFlex space solar arrays, produced by the company’s space components division.
The service module, which houses the spacecraft’s avionics, electrical, propulsion and communications systems, will integrate with an extended Pressurized Cargo Module (PCM) already in place at the Kennedy Space Center. The PCM enables larger cargo deliveries to the station. Orbital ATK has a second Atlas 5 mission scheduled to depart from Kennedy in the spring of 2016, followed two CRS missions with the upgraded Antares from Wallops Flight Facility in Virginia.

“With OA-4 set to launch in December and at least three additional missions to the Space Station planned in 2016, we remain solidly on schedule to meet our CRS cargo requirements for NASA,” said Frank Culbertson, president of Orbital ATK’s Space Systems Group.