Sunday, May 29, 2011

Endeavour set for last, unique station departure

Six Endeavour astronauts are in their final hour docked at the International Space Station before departing to begin a two-day journey home to Kennedy Space Center and Endeavour's final landing.

Endeavour's 12th and final undocking from the station will be like no other.

After flying a customary lap around the outpost and retreating about 20,000 feet (less than four miles), the orbiter will re-approach the station to test a prototype rendezvous and docking system being developed for the Orion spacecraft.

During the unprecedented "re-rendezvous," Endeavour will come within about 300 feet behind and 1,000 feet below the station, mimicking the trajectory Orion would fly.

Orion is being developed for deep space missions and as a backup for trips to the space station that are expected to be made by commercial carriers.

Endeavour is scheduled to push away from the outpost at 11:55 p.m. EDT.

Within about 25 minutes, pilot Greg Johnson will lead the orbiter through its final lap around the outpost from a distance of about 400 feet, a maneuver performed so astronauts can take pictures and video of the station's exterior condition.

The test of the system called STORRM -- short for Sensor Test for Orion Rel-Nav Risk Mitigation -- begins at 1:36 a.m., with Endeavour reaching its closest point two hours later.

Endeavour's engines will fire to finally separate it from the station and begin the trip home at 4:38 a.m.

Hatches between the station and shuttle were closed and the two crews -- six on Endeavour and three remaining on the station -- said their goodbyes this morning before going to sleep.

The Endeavour crew awoke for the last time docked at the station at 7:27 p.m. EDT to the song “Slowness” by the Tucson, Ariz.-based band Calexico, played for commander Mark Kelly.

No comments: