The International Space Station is now more crowded than it's ever been before, with a record number of 13 people onboard.

The population boost came from the influx of seven newcomers aboard the space shuttle Endeavour, which docked Friday at 1:47 p.m. EDT (1747 GMT), and opened its hatch into the station a couple hours later.

Space station commander Gennady Padalka, a Russian cosmonaut, rang a ceremonial bell to signal the arrival of the new ship and greeted the shuttle astronauts as they floated through the door.

"This is a remarkable event for the whole space program," Padalka said. "Welcome, we are very happy."

"The crew of STS-127 is extremely happy to be here," replied Endeavour's STS-127 commander Mark Polansky. "Thirteen is a pretty big number but it's going to be an outstanding visit for us."

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Polansky came with pilot Doug Hurley, and mission specialists Chris Cassidy, Julie Payette, Tom Marshburn, Tim Kopra and Dave Wolf. Waiting onboard the station with Padalka were Roman Romanenko, Michael Barratt, Robert Thirsk, Frank De Winne and Koichi Wakata.

Kopra is slated to take Wakata's spot as an ISS Expedition 20 flight engineer, with Wakata returning to Earth aboard Endeavour. The exchange is more than a month overdue because of delays pushing back Endeavour's launch.

"Maybe Koichi is looking forward to a hot shower back home," Polansky suggested.

While there have been 13 in space at the same time in the past, they have been spread out over separate vehicles. Today is the first time one spacecraft has hosted such a large population.

"It's pretty exciting to have 13 crewmembers onboard the space station," Wakata said after they arrived. "What a great day."

Though the population jump might make for some traffic in the close quarters of the space station, the astronauts are prepared to get a lot done during the two-week stay of Endeavour. A major goal is to install the final segment of the huge Japanese Kibo laboratory - an exposed porch for outdoor science research.

"It's a lot different from what I remember last time but we're having a blast and looking forward to some hard work," said Polansky, who is making his third visit to the ISS.

The visit will also reunite two Canadians - Robert Thirsk and Julie Payette - who are the first two Canadian Space Agency astronauts to be in space at once.

"This'll be the first time that two Canadian astronauts have been on orbit. It'll be very good to see Julie and her crewmates during the Endeavour mission," Thirsk said in a preflight interview.

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