The space shuttle Atlantis successfully docked on Wednesday with the International Space Station and the hatch separating the crews was opened for the traditional welcoming ceremony, NASA said.

The shuttle and its six astronauts left Florida's Kennedy Space Centre without a hitch on Monday on an 11-day voyage to deliver a 20 000-pound haul of spare parts to the ISS.

The shuttle's final approach towards the orbiting station was manually completed by the commander Charlie Hobaugh as the two spacecraft hurtled towards each other at 28 000 kilometres an hour.

Just before docking two minutes later than planned at 4.51pm GMT, soaring 354 kilometres above Australia at the time, Atlantis approached the space station at a quarter of a centimetre per second, NASA said.

Atlantis is carrying assorted gyroscopes, ammonia tanks and other equipment too large to be launched into space aboard any other vehicle, NASA said.

With only five launches left before the 2010 retirement of the shuttle fleet, NASA officials said the parts were essential for extending the life of the space station.

"This flight is all about spares; basically, we're getting them up there while we still can," said mission director Brian Smith ahead of the mission. "You'll see this theme in some of the flights that are going to come after ours as well."