Original URL: http://www.theregister.co.uk/2010/01/13/calcitic_astro_whiz_iss_recycler/

Calcitic astro-whiz clogs ISS piss recycler

Yesterday's coffee, today's problem

By Austin Modine

Posted in Science, 13th January 2010 06:02 GMT

The mysterious properties of astronaut piss are believed to be the cause of the International Space Station's extremely troublesome deployment of its $250 million urine-recycling system.

Engineers attempting to troubleshoot the buggy barrel-shaped Urine Processor Assembly aboard the ISS now suspect that a high concentration of calcium found in astro-waste is responsible for clogging the machine, reports Reuters.

The re-wee system, which converts yesterday's coffee into tomorrow's Tang, has been on the fritz aboard the orbiting outpost since was first delivered back in November 2008. Yet before it left terra firma, the system was fully tested at NASA's Kennedy Space Center.

"We've learned a lot more about urine than we ever needed or wanted to know - some of us anyway," station flight director David Korth told the news agency.

But scientists aren't sure if the amounts of calcium are due to bone loss resulting from microgravity or other unknown factors. Past research has indicated that spending extended time in space will cause a loss in bone density.

Program scientist Julie Robinson said the chemistry changes that occur as the urine works through the processor "are not always understood." (Probably not good news for those drinking and showering in the end result.) "There are a lot of parameters including urine calcium and pH that everyone is looking at," she added.

Until then, samples of urine are being collected and stored in the ISS's Minus Eighty Laboratory Freezer for later analysis back on Earth.

The piss-recycling machine gave a clue of things to come when it was first fired up aboard the ISS in November 2008, causing the station's fire alarm to trigger. Since that day, technical snags have bedeviled the system off and on, and forced astronauts to work overtime to earn their golden showers.

Engineers hope to find a fix in time to send up replacement parts for the launch of space shuttle Endeavour's STS-130 mission planned for February 12. ®