Space station finally has a full staff of 6

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.

Each of the major space station partners is represented on board for the first time. The crew, all men, now is made up of two astronauts from Russia and one each from the U.S., Japan, Canada and Belgium.

“It is a historic day. It’s also a very happy day up here,” said newly arrived Canadian astronaut Robert 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 the 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 only temporarily.

The Soyuz spacecraft blasted off from Kazakhstan on Wednesday and pulled in at the space station as the two vessels soared 217 miles above China. 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 not an 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 arrive on Endeavour and then move in.

The first space station crew arrived in 2000, nearly two years after the first component was launched. Until now, no more than three people lived on the station at a time. The crew size dropped to two after the 2003 Columbia disaster because of the lengthy grounding of NASA’s remaining space shuttles.