The crew of Atlantis, the final mission of the US space shuttle program, are testing a urine recycling system developed by NASA that is capable of turning astronauts' pee into a tasty sports drink.

Atlantis, carrying a crew of four, arrived at the International Space Station (ISS) on Sunday to deliver a last batch of supplies. The two-day journey to the station began on Friday with an emotional send-off from the Kennedy Space Centre that was watched by about one million spectators.

Space shuttle Atlantis. Credit:AP/NASA

The "forward osmosis bags" are already being used by soldiers to clean dirty fluids but NASA has adapted the baggie system for use in space.

NASA scientist Howard Levine told Wired: "This could be a first step toward recapturing the humidity from our sweat, from our breath, even from our urine, and recycling it and making it drinkable."