Astronauts aboard the International Space Station (ISS) appeared to solve the orbiting lab's toilet troubles Wednesday as they prepared to open a new Japanese laboratory for business.

Space station flight engineer Oleg Kononenko replaced a failed pump in the station's Russian-built commode in a fix that restored the space toilet's ability to collect liquid waste.

"I see airflow right away," Kononenko said after activating the system, which uses flowing air in place of gravity to collect waste in weightlessness.

Three initial tests of the system appeared to be successful, with Russian engineers giving the station crew the go ahead to use the repaired toilet for now and report on its status.

"Okay, let's start using it," Russian flight controllers told Kononenko after two and a half hours of work.

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Built into the station's Russian Zvezda service module, the space toilet went on the fritz about 10 days ago.

Station astronauts were able to make partial repairs, though the fix required extra flush water and time-consuming overhauls every three uses, mission managers said.

"It's unfortunate that we're talking about toilets, but that really is the life and the future of human exploration in space," said Kirk Shireman, NASA's deputy station program manager, of Wednesday's space toilet surgery.

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Even in space, the same mundane maintenance jobs found on Earth are required, he added.

NASA mission managers added a last-minute spare pump to Discovery's cargo list before the shuttle's May 31 launch so astronauts could try once more to repair the seven-year-old toilet. They also included extra liquid waste receptacles in case the fix should fail.

"We use these primarily for research purposes, but we can use those for everyday use if you will," said Shireman, adding that with Discovery's delivery, the station has enough bathroom supplies to last until the next Russian cargo shipment later this summer.

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Commanded by veteran spaceflyer Mark Kelly, Discovery's seven-astronaut crew is in the middle of a 14-day mission to deliver Japan's giant Kibo laboratory, fix the station's toilet and swap out one crewmember aboard the orbital outpost.

Christening Kibo

Later Wednesday, Discovery astronauts are expected to christen the station's new tour bus-sized Kibo laboratory, a $1 billion new lab installed during a Tuesday spacewalk.

The spaceflyers will check their shuttle's heat-shield-inspection boom, which was retrieved from a storage berth on the ISS during Tuesday's spacewalk, to ensure it's in working order.

"We have a new 'hope' on the International Space Station," said astronaut Akihiko Hoshide of the Japan Aerospace Exploration Agency (JAXA) after helping install the new Kibo lab (whose name means "hope" in Japanese) on Tuesday.

Hoshide and his crewmates are scheduled to open the Kibo lab for business today at about 4:52 p.m. EDT (2052 GMT) today.

At 37 feet (11 meters) long and 14.4 feet (4.4 meters) wide, Japan's Kibo laboratory is the largest single room ever launched to the ISS and is only one of three segments that make up the station's entire Japanese space research facility.

It is designed to host a wide variety of internal and external experiments to study fluid physics, materials science and astronomy.

"We're extremely happy to see the Kibo pressurized module attached to its permanent location," JAXA's deputy Kibo operations project manager Tetsuro Yokoyama said Tuesday.

The 32,000-pound (14,514-kg) Kibo module follows an attic-like storage room, which astronauts delivered to the station in March, and includes two small windows, an airlock and a robotic arm at one end to access an external platform slated to launch next year.

A control center in Tsukuba Space Center, just north of Tokyo in Japan, will oversee the Kibo facility from Earth.

Hoshide told SPACE.com before Discovery's May 31 launch that he would likely open the new module with some sort of speech, though what he planned to say was still up in the air.

Yokoyama said he expects Japanese station flight controllers and engineers will be fairly busy during the module's activation, but there is an air of anticipation as well.

"We will be waiting," Yokoyama said.

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