A grinning multinational crew of three floated through the open hatches of the International Space station on Tuesday to join the trio already on board the experimental science lab spinning around Earth.

The Soyuz capsule carrying NASA's Sunita Williams and Japan's Akihiko Hoshide along with the Russian captain Yury Malenchenko had docked to the ISS hours earlier after taking off from Russia's Baikonur base in Kazakhstan.

The mission tested the reliability of Russia's once-vaunted space programme following a spate of accidents in the past year.

But the Soyuz -- a Soviet-developed rocket and capsule system used for both difficult docking operation and returning safely to Earth -- extended a perfect manned mission record that stretches back to 1967.

A visibly delighted Hoshide came through the catch first and was warmly embraced by Russian cosmonauts Gennady Padalka and Sergei Revin as well as NASA's Joseph Acaba -- on board since mid-May.

The hatches opened at 0723 GMT on the 37th anniversary of the historic docking of the US Apollo and Soviet Soyuz craft in what at the height of the Cold War represented the first vital piece of international cooperation in space.

"It feels great. It is just like a homecoming," Malenchenko told Russia's ground control in a traditional live teleconference conducted from the station's communication centre.

"We can see right away that some things have changed. But (the station) is in great shape and the crew looks great," said the Russian. "We are happy to be here."

Malenchenko is by far the most experienced of the new arrivals with a space travel career stretching back to 1994.

Hoshide first began training for a possible flight to the ISS in 1999 and helped set up Japan's Kibo laboratory on board the station on his only previous mission in 2008.

Williams for her part is a former US naval aviator who was once deployed to Iraq and spent almost 200 days on board the ISS in 2006-2007.

The full crew will immediately assume a hectic scheduled that includes preparations for the arrival of two Russian cargo vessels and one each from the European Space Agency and the Japan Aerospace Exploration Agency.

The Soyuz is the workhorse of Russian spaceflight that today represents the world's last human link to the 14-year-old orbiter following the launch of the last US space shuttle in July 2011.

But the system was temporarily grounded last year amid a spate of launch accidents affecting Russian cargo craft and satellites.

The head of the Roscosmos space agency said Tuesday that Russia was also coming under pressure to give up one of its three reserved seats on board the station to other international partners whom he did not name.

Agency chief Vladimir Popovkin stressed however that Russia's underfunded exploration programme intended to keep all its spots despite the financial reward giving one up would bring.

"We have no such desire," Interfax quoted Popovkin as saying.