International Space Station: Nasa Prepares to Install Japanese Lab

Nasa astronauts are today preparing for their first spacewalk after the shuttle Discovery successfully docked with the international space station.

Michael Fossum and Ronald Garan face a six and a half hour spacewalk this afternoon to prepare the bus-sized Japanese science lab, Kibo, for installation.

The two astronauts will also replace a bearing unit on the station's starboard side, which has suffered from increased vibrations and power usage since autumn last year.

Before docking, the commander, Mark Kelly, put the shuttle into a gentle 17,500mph back flip, allowing cameras on the station to take pictures of the ship's heat-resistant underbelly. This has been standard procedure since damaged tiles on the Columbia shuttle led to its destruction on re-entry in 2003.

On Monday, Nasa said Discovery's launch had caused unprecedented damage at Cape Canaveral. A section of the brick and concrete flame trench lining was flung more than 500 meters, causing damage to a perimeter fence. The flame trench deflects the blast from the rocket's engine and is regularly inspected.

The mission marks a milestone for the Japanese space program. Kibo - meaning hope - is larger than any other science module on the space station and contains facilities to conduct experiments on space medicine, biology, materials production, biotechnology and communications. Once installed, Japanese astronauts will be entitled to more seats on board future shuttle missions to the station.

The existing three members of the international space station welcomed the shuttle's arrival. They have been waiting for a pump and other spare parts needed to fix their only toilet. In the absence of gravity, the toilet uses air from fans to propel waste into a container. But last month, the crew reported the fan had stopped working after a loud bang.