BAIKONUR, Kazakhstan -- A Russian rocket carrying a new Russian-US crew to the international space station lifted off from the Baikonur cosmodrome early today.
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 US space shuttles; this is Shargin's first space flight.
The Soyuz TMA-5 lifted off from the bleak steppes of Kazakhstan and was due to dock with the station in two days.
Since the mid-1970s, Soviet and Russian space crews always have included a cosmonaut with previous pilot experience to ensure a smooth ride. The tradition now has been broken 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.
The grounding of the US 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 US 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 today'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 postponed it 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 said yesterday.
After arriving at the station, the crew will attempt 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 US 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.
Yesterday, the cosmonauts said they were confident that their mission would be completed as planned.
''I have flown shuttles three times . . . and I would very much like to fly a Soyuz, which would be a new adventure for me," Chiao said. ''Both ships are very good, very reliable."
Russian space officials played down the lack of Soyuz experience. ''We have logged many hours in a simulator and got prepared for all regular and emergency regimes," Sharipov said.
Chiao, who got married just over a year ago, said he had a mascot from his shuttle missions to take on the Soyuz, but added that the most important personal item during the mission would be his wedding ring.
Responding to a question in an official Russian questionnaire about what he would secretly bring to the station, Chiao jokingly said that he would take a good scotch or brandy.