Three astronauts returned to Earth Monday, following a 166-day mission, bringing the Olympic torch back from the International Space Station after a historic space walk.

The trip completes the most ambitious leg of Russia's unparalleled torch relay in the run-up to the Winter Olympic Games in Sochi next February.

Russian cosmonaut Fyodor Yurchikhin, NASA US astronaut Karen Nyberg and Italian colleague Luca Parmitano, descended in the Soyuz capsule to touch down at 0249 GMT on the frosty steppes of Kazakhstan.

The torch, kept unlit throughout its space journey due to safety precautions, was securely wrapped during the descent, and an employee of Russia's space agency Roscosmos took it out of the packaging. "Here's the torch!" he said, holding it up to the cameras before handing it to veteran space traveller and Soyuz captain Yurchikhin who sat smiling wrapped up in a blue blanket resting near the Soyuz.

He took off his gloves and briefly held up the heavy 1.8 kilogramme and nearly metre-long torch posing for pictures and talking to the medical staff.

After a few minutes Nyberg and Parmitano, who had completed his first space voyage, were also extricated from the craft, which had landed on its side.

The trio sat briefly in the sunshine surrounded by medical staff as well as flags of Russia and the Sochi Olympic Games, before they were taken to the heated medical tent for initial tests and changing out of their launch suits.

The capsule completed a "flawless descent" and touched down exactly on time in a "bullseye landing," a NASA TV commentator said. "The crew is feeling well," Roscosmos said in a statement.

A team of three Russians, two Americans, and a Japanese astronaut remain aboard the ISS which, before Monday's return, had been crammed with nine people who hosted a rare conference from space last week.

Russia sent the torch on its four-day space mission last Thursday and even covered the rocket in Olympic insignia.

Cosmonauts Oleg Kotov and Sergey Ryazansky on Saturday took it for a spacewalk posing spectacularly against the backdrop of the ISS and the Earth and completing a relay torch handover that was viewed live worldwide and even shown on screens at New York's Times Square.

The space-travelling torch will be the one which lights the Olympic cauldron in the Black Sea resort Sochi marking the start of the Winter Games on February 7, authorities said.

Russia has put together an impressive Olympic relay, sending the torch through all of its regions and as far as the North Pole on a nuclear-powered icebreaker.

The relay, a no-expense-spared event that has seen participation by many government officials, celebrities, and Olympic champions, will also take the torch to the world's deepest freshwater lake Baikal and Europe's highest mountain peak Elbrus.

Following Sochi's winning bid, promoted by President Vladimir Putin, Russia will host its first Olympic event since the 1980 Summer Games in Moscow, which were boycotted by a number of Western nations over the Soviet invasion of Afghanistan

Although a spacewalk with a torch was unprecedented, other Olympic torches have travelled to space on US space shuttle voyages ahead of the 1996 Summer Games in Atlanta and the 2000 Games in Sydney. (AFP)