Space shuttle Discoveryunhitched today from the orbital outpost its astronauts called home for nine days, readying itself for the long, dangerous journey back to Earth.
There were hugs and handshakes as Discovery'sastronauts said their goodbyes to the astronaut and cosmonaut who live aboard the international space station. The crews then closed the hatches between the ship and orbiting lab.
Before the spacecraft left for good, Discovery'sastronauts planned to fly a farewell loop around the station, then fire the shuttle's jets to reposition the spacecraft and prepare for the voyage home.
Discovery'sastronauts are scheduled to complete their 13-day mission on Monday when the first shuttle to return to space since the 2003 Columbiatragedy is set to land in Florida.
"We are so happy to have spent the time up here," Discovery'scommander Eileen Collins told the station's two crew members, who have been there since April. "These are memories that we will have forever."
Discovery'sseven astronauts spent a day longer than originally planned aboard the station to bring over additional supplies - such as paper, laptop computers and surplus food and batteries.
Discoveryis the first shuttle to visit the station since 2002.
Since the Columbiatragedy, unmanned Russian cargo ships have carried supplies to the station, where two-person crews rotate every six months using Russian Soyuz rockets.
The rockets don't have near the capacity of the shuttle, which is needed to complete construction of the station.
Nasa officials, meanwhile, said they were looking into whether a small crack in the foam on Discovery'sfuel tank may have caused a 1lb section of insulation to break off during its climb to orbit.
The piece of foam, which was reminiscent of the one that doomed Columbia, did not hit Discovery. However, the large piece of foam did cause the space agency to suspend future flights until it can prevent shedding of similar pieces from the external tanks, which are used to fuel shuttle launches.
The agency also is considering whether there could have been a mistake in the foam's application, whether the foam was defective or was handled by too many people, or if the tank had been damaged during its shipment to Florida from the Louisiana plant where it was manufactured.
Nasa has already spent $1.4 billion dollars and two and a half years working on the problem.
So far, space agency officials say Discovery'smission has been a success. The crew completed its goals: the resupply of the space station, bringing home the station's rubbish and intense inspections of Discoveryfor damage.
AP