Shuttle crew enters space station

The space walkers had to avoid numerous obstacles

The seven crew members on the space shuttle Atlantis have entered the International Space Station (ISS) ahead of schedule.

Earlier two of them - American astronaut Edward Lu and Russian cosmonaut Yuri Malenchenko - performed a gruelling space walk lasting more than six hours to connect cables.

The crew members opened a series of 12 hatches, to give them access to all areas of the station.

The pressure had to be equalised on either side of each hatch before they could be opened.

Malenchenko reading a manual in the Unity module

The crew of five Americans and two Russians will shortly begin transferring supplies for their three colleagues who will arrive at the ISS in November, for the first long-term stay on board.

The material includes office supplies, dictionaries, an exercise machine and a toilet.

New modules

The ISS is almost twice the size it was the last time astronauts visited it in May.

In late July, the Russian service module Zvezda was added. It is the cornerstone of Russia's contribution to the ISS, serving as the early living quarters for the station.

International Space Station

Project costing $60bn

16-nation partnership

Due for completion 2006

ISS to have six research labs

First permanent crew arrives early November

Three vehicles bringing parts - US shuttle, Russian Soyuz and Proton rockets

More than 40 space flights needed

The space shuttle Atlantis docked with the ISS on Sunday, taking an extra 2.16 tonnes of supplies for the three men who will arrive in November.

The ISS, costing $60bn, is due to be completed in 2006.

On Monday the two space walkers scaled the 42m (140 ft) exterior of the space station. Mission controllers said it was like working on the 11th storey of a 13-storey building - with the earth 368 km (230 miles) below.

Tethered to the shuttle for safety, the space walkers travelled further away from the shuttle than any other tethered astronauts have done while performing a space walk.

Russian technique

They also had mini jetpacks for added safety. Only Malenchenko had made a space walk before.

For the first time, the US space agency Nasa adopted the Russian method of space walking, using a pair of tethers as rock climbers do.

Most of the men's time was spent connecting cables that will allow Zvezda to receive power from US solar-power panels once they are assembled on future missions.

The crew of Atlantis will spend a week transferring supplies to the Zvezda.

Nasa says there is roughly 250 cubic metres (8,800 cubic feet) of living space at the moment, about the same as a comfortable apartment.