Happy birthday, space station

By Amanda Barnett
CNN

(CNN) -- Still growing like a newborn, the international space station will mark its first birthday on Friday -- that's one full year of continuous human habitation.

Named Alpha by its first crew, the station started out at 70 tons. It now weighs 150 tons, making it about the size of a three-bedroom house.

The station, which orbits at about 250 statute miles above the surface of Earth, has hosted three crews, four American astronauts and five Russian cosmonauts. Fourteen spacecraft have docked and departed from Alpha, ferrying 79 visitors from six different nations.

"During the past year, NASA has flown a series of missions as complex and challenging as any ever executed, and they have resulted in an outstanding station now in orbit," says space station program manager Tommy Holloway in a prepared statement.

"The teams on the ground worldwide and in space have performed to a standard of operational excellence as high as any achieved in NASA's history, including the landings of astronauts on the lunar surface," says Holloway.

The visitors have carried gifts to the fledgling station -- solar arrays, the U.S. Destiny space laboratory, a robot arm and two airlocks. The equipment and experiments were contributed by the station's partners including the United States, Russia, Canada, Japan and the European Space Agency.

The current crew on Alpha -- a trio called Expedition Three -- comprises, from left, Mikhail Tyurin, Frank Culbertson and Vladimir Dezhurov.

The station's current crew, U.S. commander Frank Culbertson, Russian flight engineer Mikhail Tyurin and pilot Vladimir Dezhurov, is hosting the latest visitors. Victor Afanasyev, Konstantin Kozeev of Russia and Claudie Haignere of France arrived October 23 to deliver a new Soyuz capsule to the station. The capsule is a replacement for the station's emergency return vehicle.

The guests are to depart the station on Tuesday in the old Soyuz capsule. Then on November 12, the Alpha crew is scheduled to conduct a third spacewalk to continue adding on to their home in space.

Alpha is slated to get a new crew in December when a replacement team should arrive on U.S. space shuttle Endeavour. The shuttle is scheduled for launch on November 29.