Cygnus On Track for First Arrival at Space Station Sunday Morning

Orbital Sciences Corporation’s Cygnus cargo spacecraft is on track for arrival at the International Space Station (ISS) tomorrow morning, Sunday, September 22.

The spacecraft has been making a series of orbital maneuvers since launch on Wednesday to catch up with the ISS and get ready for berthing.  (Strictly speaking this is berthing rather than docking since the spacecraft is grappled by a robotic arm operated by ISS astronauts who then install the spacecraft onto the docking port, rather than the spacecraft  itself maneuvering directly into the docking port.  Berthing is used for SpaceX’s Dragon and Japan’s HTV cargo spacecraft as well.)  This afternoon, Cygnus is about 400 kilometers (248 miles) behind and 4 kilometers (2.5 miles) below the ISS.

NASA TV will begin coverage of rendezvous and berthing operations at 4:30 am Eastern Daylight Time (EDT) Sunday morning.  At about 7:25 am EDT, NASA astronaut Karen Nyberg will use Canadarm2 to grapple Cygnus, followed by installation onto the Node 2 docking port about 90 minutes later.

A press conference is scheduled for 1:00 pm EDT.

Cygnus is delivering about 1,300 pounds (589 kilograms) of cargo to the ISS crew.  Today there are three aboard — Nyberg, European Space Agency astronaut Luca Parmitano, and Russian cosmonaut Fyodor Yurchikhin, but they will be joined by another three in a few days (September 25).

This is Orbital’s demonstration mission under NASA’s Commercial Orbital Transportation Services (COTS) program.  It was the second launch of the Antares rocket and the first launch of Cygnus.   If all goes according to plan with this mission, Orbital will launch its first Commercial Resupply Services (CRS) flight in December.  Orbital is under contract to NASA for eight CRS missions to the ISS during the next couple of years.