Outdoor survival: extreme ways astronauts get drinking water in space

Astronauts and mission control teams rank among the world's most careful packers because every extra pound launched to orbit costs thousands of dollars. Each item, even something as small as a pen, is logged and explained. Water stands out as a special headache.

The International Space Station shows why - sending one pound of supplies, water included, costs more than $1,800. Hauling huge tanks of water from Earth is out of the question.

The station solves the problem by running the liquid through high tech filters plus processors. Crew members save sweat, breath vapor, shower runoff and urine. Machines pull humidity from the air, turn it back into liquid and send it through filters. The final product is cleaner than most tap water on Earth but also tastes like commercial bottled water.

Research animals aboard the station add their own moisture and waste to the same loop. If the recyclers shut down, a four person crew would need 40,000 pounds of fresh water shipped from Earth each year.

Most of the station drinks recycled water, but the Russian side keeps extra 90-pound bags called CWCs. Russian equipment skips urine - it reuses only shower water and condensation - it saves a little less than the U.S. system.

Even the best recyclers still lose some water. Engineers keep tweaking the filters, valves as well as chemical beds to squeeze out every last drop, because every pint saved means one less pound to launch.