ISS crew will skip to $19M loo

Think earth-bound plumbing is expensive? NASA has agreed to pay an astronomical $19 million US for a Russian-built toilet system for the International Space Station.

While the price may seem out of this world, the space agency says it's cheaper than building its own system. NASA is getting the toilet as part of a $46 million contract to buy assorted hardware from the Russian aerospace company RSC Energia.

The station currently has only one toilet for its three occupants, on the Russian side. The new system will be installed on the American side in 2008, a year before the crew doubles in size to six.

The new toilet will transfer urine to a device that can produce drinkable water, NASA says. It will also offer more privacy than the old orbiting lavatory.

Like the existing toilet, also Russian-built, the new one will have leg restraints and thigh bars - and like the old system, it won't use any water. Space toilets are vacuum-operated, using a strong flow of air to pull waste into a storage tank.

Water rationing is routine in space, partly because it's expensive to ferry it from Earth. There's also the pesky problem of water droplets escaping in zero-gravity conditions. Space travellers often use edible toothpaste and special shampoo that can applied without water and wiped off with a towel.