After a successful docking, the crews of the Space Shuttle Discovery and the International Space Station are working side-by-side some 350 kilometers above the Earth.

With broad smiles, the crews exchanged greetings and then set about connecting cables and other equipment between Discovery and the space station, so that the two vessels can operate as one. Much work lies ahead, including the unloading of several tons of supplies and equipment brought by the shuttle, perhaps most importantly a new oxygen generator. At least two space walks are planned. One Discovery crewmember, Mission Specialist Thomas Reiter of Germany, will stay behind when the shuttle departs.

Earlier, having "chased" the space station for two days at speeds exceeding 28,000 kilometers per hour, Discovery performed a 360-degree "backflip" rotation before docking with the space station. It was a carefully choreographed maneuver that NASA officials described as "perfect" in execution.

At a press briefing, Shuttle Flight Director Tony Ceccacci was asked how he feels about the mission so far.

"Extremely pleased," he said. "I am very happy with how things are going. Today, talking to the crew, you can see them on TV. They are all pumped up [energized] and ready to go. And I think they are going to be on an adrenaline rush until touchdown on [re]entry day."

The summersault executed by Discovery prior to docking allowed space station crewmembers to take pictures of the orbiter's underbelly, to check for possible damage to heat-resistant tiles. The procedure is part of an exhaustive in-mission safety review process implemented after the 2003 Space Shuttle Columbia disaster. Columbia broke up upon re-entry to Earth's atmosphere, and heat-shielding tiles damaged during lift-off were blamed for the tragedy.

Wednesday, Discovery's crew used the orbiter's robotic arm to take photographs of the shuttle's wings and nose cap. NASA officials say nothing of major concern has been detected.

Among the primary goals for Discovery's mission is to demonstrate that major safety concerns stemming from the Columbia disaster have been addressed, and that the shuttle program can go forward with a series of missions in support of the completion of the International Space Station by a target date of 2010. At that point, the shuttle fleet is to be retired.