Software, vehicle congestion delay Cygnus docking at Space Station

After an apparently flawless launch last week, Orbital Sciences' Cygnus capsule was supposed to have docked on the International Space Station over the weekend. It didn't happen. Apparently, some of the data being sent down to Earth from the vehicle wasn't formatted properly, and it took a couple of days to devise a fix and get it in place. The delay pushed the window for docking too close to the arrival of a new crew, set to lift off from Baikonur Cosmodrome on Wednesday afternoon (Eastern US time). So Orbital's first rendezvous with the Station will have to wait until Saturday at the earliest.

According to NASA, Orbital technicians spent yesterday validating the software patch that fixes data formatting issues, which would clear it for rendezvous with the Station. However, NASA has several tests of its own that Cygnus must clear before being allowed to approach the Station. These include demonstrations of various control capabilities, including a simulated abort of the approach procedure. Cygnus has cleared a few of those hurdles, but there are still a few left to do.

By the time Cygnus is fully cleared, it will be too close to the Soyuz launch time for NASA's comfort. The Russian craft will be bringing three new crew members who will transition from Expedition 37 to 38.