They're unloading 2½ tons of supplies, including food, water and equipment for fixing an oxygen generator, brought up on Thursday by a robot Russian cargo ship.
There was some concern that the craft hadn't docked properly, but mission controllers in Moscow were able to work it out.
And the food is not just run-of-the-mill space snacks. It includes some gourmet meals prepared by a celebrity French chef. There's also a delivery of gifts, letters, CDs and DVDs for the three-member crew — an American, a Russian and a German.
Russian space officials said the crew faced no danger and had enough oxygen, water and food even if the ship could not be unloaded quickly.
The cargo ship docked at the station Thursday on autopilot, as planned. But Mission Control could not confirm that its antenna had folded as required for the craft to clamp securely on the station. It managed to resolve the glitch about five hours later.
In September, Russian cosmonaut Mikhail Tyurin and American astronaut Michael Lopez-Alegria began a six-month stint on the orbiting space station. They are on the outpost with German Thomas Reiter of the European Space Agency, who arrived aboard the space shuttle in July.
Tyurin faced a similar problem nearly five years ago, when he and crewmate Vladimir Dezhurov had to venture outside the station to remove an O-ring rubber seal that had jammed docking mechanisms. Both cosmonauts cut away the long, twisted seal in a December 2001 space walk.
The Progress ship, which lifted off Monday from the Baikonur cosmodrome in Kazakhstan, was delivering about 2.5 tons of equipment, water and food, including roast quail and other gourmet dishes by French celebrity chef Alain Ducasse.
It also carried equipment for repairing a Russian-built oxygen generator that overheated and spilled a toxic irritant last month, forcing the crew to don masks and gloves in the first emergency ever declared aboard the eight-year-old station.
Charles Simonyi, 58, helped develop two of the world's most popular software applications, Microsoft Corp.'s Word and Excel. He is paying Space Adventures Ltd. of Vienna, Va., $20 million to $25 million to take him to the International Space Station in March aboard a Russian Soyuz spacecraft, the company said. He would be the fifth person the company has taken to space.