for National Geographic News
The space shuttle Endeavor is set to launch this evening with an odd assortment of cargo—including live spiders, butterflies, and new technology to turn urine into drinking water.
The shuttle was cleared for a Friday launch from NASA's Kennedy Space Center in Florida earlier this week, despite a 30 percent chance that a cold front could stir up rain and thick clouds.
Besides seven astronauts, Endeavor's cargo includes two new sleeping chambers, a second toilet, and a water-purification system, all of which will let NASA double the occupancy of the International Space Station to six.
The new mission is the 124th space shuttle flight and the 27th to the International Space Station. The seven-member crew will spend 15 days performing basic maintenance on the station before returning to Earth.
The launch is set for 7:55 p.m. eastern standard time. Forecasters have put the odds of acceptable conditions at 70 percent on Friday and just 40 percent on Saturday, with a much better chance of success on Sunday.
(See a video of the space shuttle Atlantis launching in February 2008.)
This mission is "all about home improvements" at the International Space Station, said Endeavor commander Chris Ferguson in a statement.
That includes a state-of-the-art, urine-purification system to enhance the station's water-recycling abilities. Astronauts already recycle the steam from their showers, the water from their shaving and toothbrushing—even their sweat.
Mike Leinbach, shuttle-launch director, said the "truly closed-loop water system" is the most exciting cargo aboard Endeavor.
"Reusing water in orbit is an essential technology for the longer-term missions that lie ahead—those to the moon, the near Earth asteroids, and Mars," he wrote in an email on Thursday.
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