The space shuttle Endeavour is seen docked at the International Space Station in this view taken by an exterior camera on Feb. 10, 2010. At top, the station's new Tranquility module and dome-shaped Cupola window addition can be seen in the shuttle's payload bay.
Credit: NASA TV
Astronauts aboard the International Space Station tackled a tricky repair of their urine recycling system Wednesday while engineers on Earth study two issues on the space shuttle Endeavour.
Station commander Jeffrey Williams is expected to spend hours today replacing a broken urine recycler part and pump inside the orbiting lab?s water recovery system while other astronauts unload cargo and prepare for a Thursday night spacewalk.
The spare parts for the repair were delivered by NASA?s space shuttle Endeavour, which docked at the station early Wednesday carrying six astronauts and a new room and observation deck for the orbiting lab.
Meanwhile, engineers at NASA?s Mission Control center in Houston are studying two minor concerns on the shuttle Endeavour.
Photos of the spacecraft taken before it arrived at the space station revealed a ceramic spacer jutting out near one of Endeavour?s cockpit windows. Also, a once-repaired crack in a white heat-resistant tile on top of the shuttle?s cockpit has reappeared.
Deputy shuttle program manager LeRoy Cain said neither issue is expected to pose a serious concern for Endeavour or its crew. But engineers are checking them out just to be sure, he added.
A repair of either item is not expected to be required, but they would be within reach of spacewalkers should one be needed, Cain said.
Mission Control also radioed Endeavour?s crew to say the shuttle?s heat shield looks to be in good shape. No extra inspections will be required during the eight days Endeavour is linked to the station, mission managers said.
NASA has kept a close watch over shuttle heat shield health since the 2003 Columbia disaster.
Drinking recycled urine
Mission managers hope Williams will be able to reactivate the urine recycler so it can be tested later in the mission. The urine recycler and larger water recovery system are due to be moved into the new station room being delivered by Endeavour?s crew.
?We think we?ll be able to take as much time as we need to try to restore functionality of the system,? said shuttle flight director Kwatsi Alibaruho today.
Astronauts began drinking recycled urine, sweat and condensation last year using a $250 million water recovery system designed to support full six-person space station crews and cut down on the amount of water shipped to the orbiting laboratory.
The keg-sized urine recycler component, called a distillation assembly, includes a spinning centrifuge that helps filter astronaut urine back into pure drinking water through a seven-step process. It has been replaced twice since the first one launched in late 2008 (most recently last November).
?The concept is very simple,? explained Don Holder, chief engineer at NASA?s Marshall Space Flight Center in Huntsville, Ala., who helped devise the repair plan. ?Basically, you are boiling urine. The problem is that, in effect, you don?t have gravity anymore. So you need this centrifuge to help separate the urine.?
Holder told SPACE.com that a buildup of calcium from the astronauts? urine likely clogged an overflow hose in the centrifuge, leading to slight flooding.
They refurbished an older distillation assembly from storage and sent it aboard Endeavour for delivery, along with a new pump. Engineers hope to fully reactivate the urine recycler, as well as the larger water system and a related oxygen generator.
William and his station crew have up to 11 containers of stored urine aboard to run through the recycler to make sure it?s working.
Endeavour?s six-astronaut crew is flying a 13-day mission to deliver a 23-foot long module named Tranquility in honor of the Apollo 11 moon landing. The shuttle also delivered a seven-window observation dome that will be attached to the new module during the mission.
Both additions were built by the European Space Agency and together cost about $409 million.
While Williams repairs the urine recycling system, Endeavour?s astronaut crew will move cargo from the shuttle into the space station.
The astronauts will also resize a spare spacesuit to fit crewmate Robert Behnken, Endeavour?s lead spacewalker. Behnken?s spacesuit suffered a glitch that has failed to power its onboard heaters and lights.
NASA ordered the crew to resize a spare suit on the station for the mission?s three spacewalks to install a new room and observation deck at the space station.
The spacesuit swap is not expected to affect Behnken?s comfort or work during the upcoming spacewalks.
The first spacewalk is set for Thursday night and expected to be particularly challenging. Mission Control gave the astronauts a half-day off later tonight to rest up. The crew is flying on an overnight schedule in which they work at night and sleep in the day.
- Astronauts Drink Recycled Urine, and Celebrate
- Video - Recycled Space Urine: Would You Drink It?
- Video Show - Mission Endeavour: Space Windows and Rooms
SPACE.com is providing complete coverage of Endeavour's STS-130 mission to the International Space Station with Managing Editor Tariq Malik and Staff Writer Clara Moskowitz based in New York. Click here for shuttle mission updates and a link to NASA TV.