Shuttle Discovery heads back to Earth

HOUSTON, Sept. 9 (UPI) -- Space shuttle Discovery's crew was to perform a flight control system check Wednesday while en route back to Earth, in preparation for a Thursday landing.

NASA said Discovery was scheduled to land at the Kennedy Space Center Thursday at 7:05 p.m. EDT.

During their STS-128 mission to the International Space Station, the shuttle crew completed all of their major objectives, including three spacewalks, transferring 17,000 pounds of cargo and delivering three major research facilities, the space agency said.

"Space shuttle Discovery undocked from the International Space Station Tuesday at 3:26 p.m. EDT.," NASA said in a statement. "Once safely separated from the orbiting complex by about 450 feet, pilot Kevin Ford conducted a fly-around of the space station using only the primary reaction control system steering jets. The smaller vernier jets were disabled before the shuttle docked to the station because of a small leak in one jet. A final separation burn occurred around 5:09 p.m."

NASA astronaut Tim Kopra is aboard the shuttle, returning to Earth after 44 days as a member of the space station's Expedition 20 crew, the space agency said. His replacement, astronaut Nicole Stott, is beginning a three-month stay in orbit.

Also aboard the shuttle are 2.5 tons of experiment specimens, used equipment and trash from the space station.