Orbital Sciences has confirmed that Sunday morning, Sept. 22, 2013, around 1:30 a.m. EDT, its Cygnus spacecraft established direct data contact with the International Space Station (ISS) and found that some of the data received had values that it did not expect, causing Cygnus to reject the data. This mandated an interruption of the approach sequence. Orbital has subsequently found the causes of this discrepancy and is developing a software fix. The minimum turnaround time to resume the approach to the ISS following an interruption such as this is approximately 48 hours due to orbital mechanics of the approach trajectory.
Cygnus launched Sept. 18, 2013, aboard an Antares rocket at 10:58 a.m. EDT from NASA’s Wallops Flight Facility in Virginia after a 24 hour delay due to poor weather preventing its roll-out to the launch pad.
It has several demonstration objectives it must complete before NASA approves its capture by the Canadarm2 and its berthing to the Harmony node. The Cygnus has already achieved three of its demonstration objectives during its first two days in orbit. The vehicle first demonstrated its position and control ability, or its ability to orient itself in space; second, the vehicle turned off its engines and operated while in free drift; third, Cygnus conducted a demonstration abort maneuver.
When Cygnus meets its final demonstration objective of pointing a tracking laser at a reflector on the Kibo laboratory it will move to its capture point about 10m from the station. Cygnus will turn off its thrusters, operating in free drift, and Expedition 37 Flight Engineer Luca Parmitano will maneuver the Canadarm2 to grapple and capture the new resupply craft. After capture, Parmitano will operate the Canadarm2 to move Cygnus and attach it to the Harmony node. The hatches to Cygnus are planned to be opened following leak checks and power connections.