Washington  - The lone toilet aboard the International Space Station is working again after a pump was replaced to fix the multimillion-dollar system that had not been working for a week and a half.

Russian cosmonaut Oleg Kononenko carried out the plumbing work Wednesday, after which astronauts opened a newly installed Japanese laboratory, the US space agency, NASA, said.

The Russian-built, 7-year-old toilet lost suction late last month, making life in zero gravity a little more uncomfortable for the station's three-member crew. It fashioned a manual fix to the problem, but flushing then required 10 minutes and the work of two people, the National Aeronautics and Space Administration said.

The replacement pump was brought to the station by the space shuttle Discovery, which lifted off Saturday on a 14-day mission to the station.

Its biggest cargo, however, was the 1-billion-dollar, bus-sized Kibo laboratory, which two of the seven Discovery astronauts installed in a seven-hour spacewalk Tuesday.

The crews opened the module Wednesday after checking the air quality in the lab, whose name means "hope" in Japanese.

Shortly after being the first person to drift through the hatch into what is now the largest room on the space station, Japanese astronaut Akihiko Hoshide held up a sign that said "Welcome" in both English and Japanese on NASA television. (dpa)