A Russian rocket carrying two cosmonauts and an American astronaut to the international space station lifted off from the Baikonur cosmodrome on Thursday.
For Russians Salizhan Sharipov and Yuri Shargin and American Leroy Chiao, it was the first mission in a Soyuz spacecraft - breaking the nearly 30-year tradition of having at least one crewman with previous experience in piloting the capsule.
Chiao and Sharipov both have flown U.S. space shuttles, while Shargin is a rookie.
The Soyuz TMA-5 lifted off from the bleak steppes of Kazakhstan at 7:06 Moscow time and is due to dock with the station two days later.
Since the mid-1970s, Soviet and Russian space crews always have included a cosmonaut with previous pilot experience to ensure a smooth ride. That practice has been changed because several veteran cosmonauts have resigned in recent years and the space agency hasn't had enough seats on recent Soyuz missions to train their replacements, said Yuri Grigoryev, a spokesman for Russia's Cosmonaut Training Center.
"It's not a problem. We simply need to adapt to new conditions," he said.
Russian space officials have played down the lack of Soyuz experience, and the crew said Wednesday that thorough training had compensated for it.
"We have logged many hours in a simulator and got prepared for all regular and emergency regimes," Sharipov said.
Soyuz spacecraft are guided by autopilot on their approach to the station and during the docking, but the crew is trained to operate it manually in case of computer failure.
"We hope that the docking will be conducted in automatic mode, but the crew is ready to switch to manual controls if the need arises," Sharipov said.
Nikolai Moiseyev, a deputy director of Russia's Federal Space Agency, scoffed at a question about the crew's lack of Soyuz experience. "Yuri Gagarin's flight was also his first," he snapped, referring to the Russian who in 1961 became the first man to fly in space. "Our training methods are reliable and give us full confidence."
The grounding of the U.S. shuttle fleet following the Feb. 1, 2003, Columbia disaster has left Russian spacecraft as the sole link to the 16-nation station. One of three seats on the latest Soyuz missions was assigned to a U.S. astronaut.
In order to earn some extra cash, the underfunded Russian space agency has also sold several seats to European astronauts or space tourists.
Initial plans for Thursday's mission had envisaged including a space tourist, Russian millionaire businessman Sergei Polonsky, who said he was ready to pay some $20 million for a 10-day ride in space. Polonsky was eventually jettisoned from the mission after officials said he was too tall for the tiny Soyuz capsule.
Polonsky was replaced by Shargin, a Russian military officer who is to return to Earth 10 days later with the station's current crew, Russian Gennady Padalka and American Mike Fincke, who are ending a six-month mission.
The mission's launch has been delayed twice because of technical malfunctions. It initially was set for last Saturday, but officials pushed it back after the accidental detonation of one of the explosive bolts used to separate the ship's various components.
The launch had to be delayed again when a tank with hydrogen peroxide burst because of a sudden change in pressure, said Yuri Semyonov, the head of the RKK Energia company, which built the Soyuz.
Semyonov said the faulty equipment had been replaced and neither of the two glitches could affect flight safety.
"We are fully confident that the ship is ready, and we don't have any concerns," Semyonov told reporters Wednesday.
After arriving at the station, a crucial task for the crew will be to fix a broken generator that makes oxygen from waste water. Previous repair efforts have failed, and the new crew is bringing spare parts.
Oxygen supplies on the station are running out, and U.S. space officials have warned that if Russians fail to launch the next Progress cargo ship by late December to replenish them, the station could temporarily be abandoned.
During the six-month mission, the new crew also is set to conduct experiments to research new AIDS vaccines, study plant growth and conduct at least two space walks.
By Vladimir Isachenkov