The international space station just had a population boom.
A Russian Soyuz capsule carrying three new space station residents docked at the orbiting complex Friday. With three astronauts there to greet them, the space station now has a full staff of six for the first time in its 10-year history.
What's more, each of the major space station partners is represented on board for the first time. The combined crew, all men, now includes two Russians and one American, Japanese, Canadian and Belgian.
"It is a historic day. It's also a very happy day up here," said newly arrived Canadian astronaut Bob Thirsk. "We've got an incredible potential for success here. This is going to be something incredible. You ain't seen nothing yet."
Having all these countries represented on board is "a great way to kick off a six-person crew," NASA's deputy space station program manager, Kirk Shireman, said on the eve of the linkup.
When shuttle Endeavour and its crew of seven arrives in another few weeks, a record 13 people will be at the space station, but that will be only temporary.
The Soyuz spacecraft blasted off from Kazakhstan on Wednesday and pulled in at the space station as the two vessels soared 217 miles above the China coast. There were hugs and handshakes all around when the hatches between the two craft swung open. The six astronauts gathered in the main living quarters for the many congratulations that streamed upward.
"Finally, we've lived to see this moment," Russian Mission Control radioed.
NASA expects science research to triple at the space station. Until now, astronauts have had to spend most of their time keeping all the systems running and fixing things, like a urine-into-drinking water machine that took months to coax into operation. Astronauts took their first sips of the recycled water in orbit last week.
There should be a mental bonus as well with a bigger crew.
Psychologists have long said three is hardly the ideal crew size because of the potential for one person to feel left out.
"Think about when you're 7 years old and you've got three kids," noted U.S. astronaut Timothy Kopra, who will fly up aboard Endeavour and then move in.
The first space station crew arrived in 2000, two years after the first part was launched. Until now, no more than three people lived up there at a time. The crew size dropped to two following the 2003 Columbia disaster because of the lengthy grounding of NASA's remaining space shuttles.
The space station has since expanded to nine rooms, three of them full-scale labs, and is now 81 percent complete. There are five sleeping compartments, two toilets, two kitchens and two mini-gyms. Another sleep station and more exercise equipment will be coming in August, and a dining table big enough to accommodate all six inhabitants will be launched early next year.
Those immense supply runs will end, though, when the shuttles are retired at the end of next year. NASA hopes to stockpile big spare parts at the space station before that happens; Endeavour, in fact, will carry up some on the next shuttle mission.
NASA also will have to rely on the Russian Space Agency to transport all its astronauts up and down, during the estimated five years between the final shuttle mission and the first ferry flight with a replacement spacecraft.
The round-trip Soyuz ride will cost $51 million per American astronaut. That's considerably more than the $35 million paid by the most recent space tourist, Charles Simonyi, an American software entrepreneur who flew last month.
A NASA spokesman said Thursday that the space agency did not take part in the space tourist contract negotiations and therefore could not comment on the difference in price. But the spokesman, Kelly Humphries, noted that Soyuz seats purchased by NASA in 2008 were $47 million apiece and the newest price reflects general increases.
As for the next shuttle flight to the space station, Endeavour is scheduled to blast off June 13 with the final components for the Japanese laboratory that's already up there. That mission, however, could be bumped into July. Stormy weather at NASA's launching site has delayed launch preparations.