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. The third operational mission,
Orb CRS-3, was not successful due to an
Antares failure during launch. The company decided to discontinue the Antares 100 series and accelerate the introduction of a new propulsion system. The Antares system was upgraded with newly built
RD-181 first stage engines to provide greater payload performance and increased reliability. In preparation for unberthing, Cygnus was grappled by
Canadarm2 on 2 June 2017. Early on 4 June 2017, the bolts securing Cygnus to the station were retracted, and Canadarm2 unberthed the spacecraft at 11:05UTC. Crew members aboard the station maneuvered Cygnus to its release attitude, and at 13:10UTC the vehicle was released from Canadarm2. One minute later, Cygnus began carrying out a series of departure burns to move it away from the ISS. Reentry for Cygnus is scheduled for 11 June 2017; as the vehicle begins breaking up in Earth's atmosphere, three probes will be released as part of the RED-Data2 experiment, collecting data on how high-temperature materials react to reentry, as well as helping to characterize how spacecraft break up on reentry. Orbital ATK announced on 11 June 2017 that the OA-7 mission had formally ended at 17:08UTC with the reentry and destruction of the S.S.
John Glenn. The spacecraft reentered east of
New Zealand over the
Pacific Ocean, disposing of approximately of trash and unneeded hardware. == Spacecraft ==