Discovery docks with international space station

HOUSTON - The space shuttle Discovery docked flawlessly with the International Space Station 341km above the earth overnight to begin an eight-day stay on a mission critical to the future of both spacecraft.

With flight commander Steve Lindsey at the helm, Discovery gently linked up with the station in a delicate space dance performed as they sailed along at 28,000km/h.

The shuttle crew will deliver more than 2272kg of equipment and supplies to the station before their scheduled departure on July 14 and drop off German astronaut Thomas Reiter for a six-month stay.

Also, shuttle crew members Piers Sellers and Michael Fossum will perform spacewalks that include repairs to a broken station transport system needed to complete construction of the half-finished US$100 billion ($168 billion) space outpost.

Before docking, Lindsey manoeuvred the shuttle through a slow back-flip while station astronauts Jeff Williams and Pavel Vinogradov photographed heat-resistant tiles on Discovery's belly that protect it during the scorching return to Earth.

The photos are part of the ongoing inspection process that began at Discovery's launch from Florida on Tuesday and has turned up no apparent significant damage to the spacecraft.

Nasa officials hope the clean bill of health so far indicates they have solved the problem of falling foam from shuttle fuel tanks that caused the Columbia disaster in 2003 and appeared again in the first post-Columbia shuttle flight last summer.

Another accident or serious problem could ground the shuttle fleet permanently before its planned retirement in 2010.

That, in turn, would mean the space station construction, which depends on the shuttle transport capabilities and has been on hold since Columbia, could not be finished.

Nasa hopes to fly 16 shuttle missions to complete the station before the spacecraft it has flown since 1981 is phased out.

A few pieces of foam, which insulate the tanks from ice formation, shook loose from the fuel tank as Discovery ascended toward space on Tuesday, but they were small in comparison to the 756g chunk that broke a hole in Columbia's wing heat shield.

Nasa engineers said sensors and cameras had picked up several possible debris impacts on the shuttle during launch and a small protrusion of gap-filling material on a wing, but nothing that raised great concern to this point.

"Overall, the tank performance was really outstanding," flight director John Shannon told reporters.

Columbia disintegrated as it returned to Earth because its broken heat shield allowed fiery gases to enter its structure. The seven astronauts on board were killed.

Since then, Nasa has spent US$1.3 billion on safety upgrades trying to prevent another shuttle disaster.

Reiter's arrival at the station marks the first time it has had a full three-man crew since May 2003. The crew was cut back to two after the Columbia accident to save on supplies.

Reiter, who previously made a six-month flight on the Russian Mir space station, also becomes the first resident station crew member who is neither American or Russian.

Williams and Vinogradov have been on the space station for 99 days.

- REUTERS