The 10 space station and shuttle astronauts gather in the Destiny laboratory module for the change-of-command ceremony. Photo: NASA TV/Spaceflight Now

After an interruption to check and reset an errant smoke alarm in the Russian Zarya module, the combined crews videotaped the ceremony and downlinked it to mission control.

"I'm happy to say the material and working condition of the lab, including the robotics workstation and the robotics system, is in excellent condition and soon to be even better," said outgoing U.S. flight engineer Daniel Bursch. "Good luck to Expedition 5 and I hope your journey is as rewarding and fulfilling as it was for me."

Expedition 4 crewmate Carl Walz told the incoming station fliers "the airlock systems are all operating very well and also the Soyuz (lifeboat) is in great shape. We wish you all the best on your voyage here in the future."

Onufrienko then wished Mir-veteran Korzun good luck, saying "now, I'm ready to be relieved."

"I relieve you of command, sir," Korzun replied. "And I want to tell you for us, it will be a good time and we will be very happy to repeat the same phrase as the previous crew. But most of all, we hope we can add something, S1 and P1."

He was referring to a pair of huge solar array truss segments that will be delivered to the station during his crew's tenure. With those comments, someone rang the ship's bell in the Destiny laboratory module and the two crews exchanged hugs and handshakes.

Onufrienko, Walz and Bursch were launched to the station Dec. 5. Assuming an on-time landing aboard the shuttle Endeavour on June 17, the Expedition 4 crew will have logged 193 days 17 hours and 20 minutes off the planet, a new U.S. space endurance record.

Korzun and his two crewmates, NASA biochemist Peggy Whitson and cosmonaut Sergei Treschev, plan to remain aboard the outpost until mid October when they will be replaced by a fresh crew. The space station has been continuously manned by three-person crews since Nov. 2, 2000. As of today, that works out to 585 straight days.

Today's change-of-command ceremony was strictly a formality. Korzun and company have been officially in charge since Friday. That's when the custom seatliners and pressure suits would need for an emergency descent to Earth in the station's Soyuz lifeboat were transferred from Endeavour to the station.

The official start of the Expedition 5's tenure aboard the station was logged at 6:55 p.m. Friday. Whitson is sleeping in the U.S. Destiny laboratory module while her two Russian crewmates are bunking in a pair of staterooms in the Zvezda command module at the other end of the station.

For his part, Korzun downplays the significance of serving as commander of the international space station.

"You know, what does it mean, 'commander?' My main duty to do science experiments and not only science, replace equipment, fix some equipment and a lot of things," he said in a NASA interview. "Approximately 40% of my activity, it will be science experiments. ... I hope results of these experiments will help the people on the ground."

But when asked to name the most significant contribution his crew might make, he said his goal was to inspire the youth of the world.

"There is a more important romantic reason, because the people on the ground know about station, and the children want to be cosmonauts, astronauts, to fly in space, and this is dream for them," he said.

"I understand government and the country maybe measure money, evaluate how many money, money they put in the space program, but nobody calculate what we will have in the future when the people, when the new generation, will think about it. And I think this is good dream for children now."