A Russian-U.S. crew returned to Earth from the international space station Sunday in a pinpoint landing on the Kazakhstan steppe, and NASA's chief said the United States wanted to continue the joint relationship on future missions to Mars (search).

Russian rockets and the non-reusable Soyuz (search) space craft have been the only way NASA can get to the space station and back since the U.S. shuttle fleet was grounded after the Columbia burned up on re-entry in February 2003, killing all seven astronauts aboard.

The bell-shaped Soyuz TMA-4, carrying Russian cosmonauts Gennady Padalka and Yuri Shargin and American astronaut Mike Fincke (search), parachuted down to the landing site, some 55 miles north of the Kazakh town of Arkalyk, at 4:36 a.m. (8:36 p.m. EDT Saturday).

The return marked Padalka's and Fincke's first experience with gravity after a six-month stay on the orbital outpost. Shargin spent eight days on the station after arriving Oct. 16 with the station's new two-man crew, Russian Salizhan Sharipov and American Leroy Chiao.

Search crews took just 14 minutes to reach the Soyuz capsule after its landing, compared with the average 90-minute search after nighttime arrivals, said Vasily Tsibliyev, head of the Cosmonauts' Training Center at Star City, outside Moscow.

The Soyuz's return flight "was another successful effort for a continuous presence on the international station," O'Keefe said at Russian mission control outside Moscow.

NASA Administrator Sean O'Keefe praised the Russian space agency workers, especially the helicopter-based search and rescue crews, for their "tremendous professionalism."

He also said America wants to further that cooperation by drawing on the Russian space program's extensive experience in long duration flights when NASA embarks on missions beyond the moon and to Mars.

"The first international partner we see to collaborate with most is our colleagues Rosaviakosmos, given the vast experience they have had in long duration space flights," O'Keefe said. Rosaviakosmos is the Russian space agency.

Russian cosmonauts own all the space endurance records, set on the Mir space station. Cosmonaut Valeriy Polyakov spent 438 days aboard the Mir for the all-time record. Earlier, Vladimir Titov and Musa Manarov spent 366 days in space.

The longest American stay in space was 188 days by astronaut Shannon Lucid aboard the Mir in 1996.

The longest American stay at a U.S. space station was 84 days aboard Skylab in 1973 by astronauts Gerald Carr, Edward Gibson and William Pogue.

After being helped out of the capsule by the search team, the three fliers sat in chairs, sipping hot drinks and bundling in blankets, and then underwent brief medical checks in a nearby tent before flying to Star City.

The Soyuz spacecraft, the workhorse of Russia's cash-strapped space program, boasts a stellar safety record.

But minor glitches occasionally occur. Earlier this month, the crew arriving at the space station had to turn off the autopilot, apply the brakes and manually connect the Soyuz to the docking point after an unidentified problem prompted the craft to approach the station at dangerously high speed.

In May 2003, the first time American astronauts returned on the Soyuz, a computer malfunction sent the crew on a dive so steep their tongues rolled back in their mouths. The crew landed so far off target that more than two hours elapsed before rescuers knew the men were safe.

Now the Soyuz is outfitted with satellite phones and a global positioning satellite system. Russia also requests that the former Soviet republic of Kazakhstan close off a large area of its airspace before the scheduled landing.

NASA has said that shuttles should be flying again by early summer.