Thursday, December 10, 1998 Published at 17:01 GMT
Eat my shorts...in space
In space there is nowhere to wash your clothes
By BBC News Online Science Editor Dr David Whitehouse
It is a problem that Russian cosmonauts have great experience of. During long weeks aboard the Mir space station, with re-supply craft arriving every two or three months, how often should you change your underwear?
After all, space and laundry facilities 200 miles up in Earth orbit are not extensive. How long should you wear them and how many old pairs can be safely stored?
The solution to this, one of long-duration spaceflight's unspoken problems, could soon be solved. Russian scientists are designing a cocktail of bacteria to digest astronauts' cotton and paper underpants.
The resulting methane gas given off by the bacteria could even be used to power the spacecraft, they claim.
"This will be a revolution in the science of biodegradation," Vyacheslav Ilyin, project director and head of the microbial ecology laboratory at the Russian State Research Centre's Institute for Biological and Medical Problems in Moscow, told New Scientist magazine.
The disposal unit will be able to process plastic, cellulose and other organic waste aboard a spacecraft.
"Cosmonauts identify waste as one of the most acute problems they encounter in space," said Ilyin. Each astronaut produces an average of 2·5 kilograms- or up to 9 litres-of uncompressed waste a day.
To keep waste to a minimum, they are forced to wear underwear for up to a week at a time.
Aboard Mir, waste is stored in sealed containers until a Progress supply module arrives with fresh supplies. Waste is then transferred to the module, which burns up and disintegrates as it re-enters the Earth's atmosphere.
Budget problems mean that Progress modules call infrequently. Meanwhile, stored waste builds up on the station, taking up valuable space and posing a potential health threat to crew.
The search for the most suitable combination of microbes is expected to take up to a decade.
The problem of hygiene in space will reach a new frontier soon. Mir will probably be destroyed in the Earth's atmosphere in the year 2000. When astronauts begin living on the new International Space Station they will have better laundry facilities and will probably change their underwear every other day.