In 1997 engineer John Lewis took part in an experiment designed to see whether four people could survive in a closed—loop life—support system. That means nothing goes to waste—not even a drop of water—no matter where it comes from.

For about three months the crew was sealed inside a three-story chamber at Johnson Space Center in Houston, Texas. They washed their hands in recycled sweat, measured and weighed how much they went to the bathroom, and even drank each other’s urine! Sounds disgusting, right? It wasn’t. All the body wastes were collected and purified. “Our drinking water was cleaner than water out of a tap,” says Lewis.

Another idea will be tested in 2001, when the oxygen-and-fuel production system will be launched on the Mars Surveyor 2001 Lander. The lander will take a tiny chemical maker to Mars to produce oxygen and fuel. If it works, NASA can move to the next phase.

Our eventual goal, explains aerospace engineer Scott Baird, “is to live off the land.” In preparation for the astronauts’ arrival, a cargo carrier will reach Mars first and drop off a large chemical maker and inflatable habitat.

It will take six months for astronauts to travel to Mars. Once there, they will study and explore Mars for 500 days before returning to Earth. Their landing craft, expanded with the attached inflatable habitat, will serve as their home away from home. “It’ll be a blast,” says Baird. “And by the time the kids of today grow up, they may be able to go.”