Spaceflight Insider

Orbital ATK aiming for second half of September for RTF of Antares

Orbital ATK OA 6 Cygnus spacecraft approaches the International Space Station. NASA photo posted on SpaceFlight Insider

Photo Credit: NASA

Upon the completion of a stage test conducted at Pad-0A at the Mid-Atlantic Regional Spaceport this past May, Orbital ATK, based in Dulles, Virginia, has announced that it could conduct the inaugural flight of its Antares 230 rocket as early as the second half of September of this year (2016).

According to a release issued by Orbital ATK and re-posted by NASA: “Orbital ATK is currently working with NASA to target a window in the second half of September for the launch of the OA-5 mission. A more specific launch date will be identified in the coming weeks.”

Meanwhile, Orbital ATK also has been working on checking out the launch vehicle to ensure it is ready to support the mission. NASA has stringent safety requirements for any vehicle visiting the International Space Station, and the OA-5 Cygnus that Antares is tasked with sending aloft must also be reviewed before being given the green light to travel to and be berthed with the ISS.

OA-5 mission profile image credit Orbital ATK posted on SpaceFlight Insider

Cargo Resupply Mission Overview. (Click to enlarge) Image Credit: Orbital ATK

NASA, Orbital ATK, and the space agency’s other commercial partners must coordinate their comings and goings to the orbiting laboratory. This is necessary to guarantee that the proper amount of supplies and the correct experiments are sent to the ISS at the appropriate times.

At present, the OA-5 “Enhanced” Cygnus is set to carry some 5,290 lbs (2,400 kg) of cargo, crew supplies, and experiments to the ISS. Orbital ATK’s CRS agreement stipulates that the company must transport some 63,273 lbs (28,700 kg) of cargo, in total, to the space station.

If everything goes as planned, this will mark the sixth Cygnus spacecraft that will be sent to the ISS. So far, five of the soda-can shaped vessels have already ventured to the ISS. Three via Antares rockets and two via United Launch Alliance Atlas V 401 rockets.

While the two flights out of Cape Canaveral’s Space Launch Complex 41 (one of the launch sites of ULA’s Atlas V) were successful, Orbital ATK has worked to return to the business of launching its Antares rockets from Virginia Space’s Mid-Atlantic Regional Spaceport Pad 0A on Wallops Island, Virginia, at NASA’s Wallops Flight Facility.

One of the changes that should be seen during the flight of OA-5 will be the new rocket engines that Antares will use. Rather than rely on the AJ26 rocket engines that are thought to have caused the loss of the Orb-3 mission, Orbital ATK has transitioned to two RD-181 rocket engines.

After the Antares 230 sends Cygnus to low-Earth orbit, the S.S. Alan G. Poindexter (the name given to this specific Cygnus) will be maneuvered to a low parking orbit before venturing toward the space station.

Like the cargo version of SpaceXs Dragon spacecraft, the OA-5 Cygnus will not dock with the ISS. Rather, it will be captured by the Expedition 48/49 crew who will be on board the space station and berth it to the ISS.

After the crew has removed the cargo and replaced it with waste and items to be disposed of, it will depart the station and begin what has been called “secondary missions”.

Like OA-6 (which launched on March 23, 2016), OA-5 will continue research being conducted to see how flames spread in the microgravity environment. On the prior flight of a Cygnus to the ISS, Orbital ATK’s spacecraft was used as a platform to carry out. the Spacecraft Fire Experiment (Saffire-I).

OA-5 should also see the deployment of Spire Cubesats via a NanoRack deployer. These miniature spacecraft will be used to aid in weather forecasting. Both this and Saffire-II will be conducted after the OA-5 Cygnus has departed the station.


Jason Rhian spent several years honing his skills with internships at NASA, the National Space Society and other organizations. He has provided content for outlets such as: Aviation Week & Space Technology,, The Mars Society and Universe Today.

⚠ Commenting Rules

Post Comment

Your email address will not be published. Required fields are marked *