Shuttle Discovery Undocks From Space Station

This story was updated at 5:12 p.m. EDT.

Space shuttle Discovery cast off from the International Space Station Tuesday and began the trip back to Earth, wrapping up nearly nine days of joint work by 13 astronauts aboard both spacecraft.

Discovery undocked from the space station at about 3:26 p.m. EDT (1926 GMT) as the two spacecraft flew 220 miles (354 km) over western China near the Mongolian border.

?Houston and station from Discovery, physical separation,? astronaut Tim Kopra said from the shuttle as it backed away from the orbiting laboratory. Kopra is returning to Earth on the shuttle to end a two-month flight to the space station.

Sturckow and his crew launched to the station Aug. 28 on a 13-day mission to deliver vital supplies, science gear and a new crewmember for the space station?s six-person crew. They performed three spacewalks to retrieve old experiments from the station, replace a massive coolant tank and swap out broken components.

?Alright, you guys, Godspeed, you?re on your way home,? said station astronaut Michael Barratt.

Before leaving the station, shuttle pilot Kevin Ford flew Discovery on a victory lap around the orbiting lab while his crewmates took photographs. Astronauts on the station also watched as Discovery circled their spacecraft.

?Those were great views of that magnificent spaceship as it flew under us,? Barratt said. ?We were all glued to the windows.?

Skywatchers in the United States and southern Canada have several opportunities over the next two days to spot the shuttle and station, weather permitting.

NASA officials also said Tuesday that the space station will not have to dodge a piece of space junk left over from a Chinese anti-satellite test in 2007. The orbital trash was expected to zip by the space station twice early Wednesday at a comfortable distance of about 15 miles (25 km) of the outpost.

Station supply run

Altogether, the astronauts delivered 18,548 pounds (8,413 kg) of supplies to the space station and are returning about 5,223 pounds (2,369 kg) of trash and surplus items back to Earth.

The nearly 11-year-old space station is now 84 percent complete and weighs about 711,000 pounds (322,504 kg), NASA officials said Tuesday. Astronauts have compared the interior living space of the station's nine rooms to the passenger cabin of a jumbo jet.

The shuttle also ferried NASA astronaut Nicole Stott to the station, where she replaced Kopra on the orbiting laboratory?s six-person crew. Stott is beginning a three-month stay at the space station with two big chores already on her plate.

Later this month, Stott will use the station?s robotic arm to capture Japan?s first-ever unmanned cargo ship and attach it to an Earth-facing berth on the orbiting lab. JAXA, Japan?s space agency, will launch the new spaceship on Thursday. It is expected to arrive at the station Sept. 17.

Stott will also help build the station?s new $5 million treadmill, which is named after TV comedian Stephen Colbert and was delivered to the station in more than 100 pieces.

Colbert won the naming rights for a new space station room in an online NASA poll earlier this year, but the space agency named the module Tranquility - the Apollo 11 moon base - to honor the 40th anniversary of the first manned moon landing. NASA named the new station treadmill the Combined Operational Load Bearing External Resistance Treadmill, or COLBERT, as a consolation prize.

Later tonight, Discovery astronauts plan to take one last look at their spacecraft?s heat shield to check for new damage from space junk or micrometeorites. The standard survey will take hours, but is identical to one performed just after launch that found the heat shield panels on Discovery?s wing edges and nose cap in fine shape.

Discovery is due to land Thursday at 7:05 p.m. EDT (2305 GMT) on a NASA runway at the Kennedy Space Center in Florida.

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SPACE.com is providing complete coverage of Discovery's STS-128 mission to the International Space Station with Managing Editor Tariq Malik and Staff Writer Clara Moskowitz in New York. Click here for shuttle mission updates and a link to NASA TV.