NASA approves space-station wastewater reuse

In a giant leap for wastewater reuse, NASA, the US federal space agency, gave the green light on 20 May 2009 to the Expedition 19 astronauts aboard the International Space Station to drink reused wastewater from the station’s new recycling system.

The decision is an important milestone in the development of the station’s environmental and life-support systems, which will begin supporting six-person crews at the end of the month.

Expedition 19 commander Gennady Padalka and flight engineers Mike Barratt and Koichi Wakata celebrated the decision with a toast using recyled water in the Destiny laboratory.

“This has been the stuff of science fiction. Everybody’s talked about recycling water in a closed loop system, but nobody’s ever done it before. Here we are today with the first round of recycled water,” said Barratt.

The 2,720 litre/year system has been processing urine into purified water since shuttle Discovery’s STS-119 crew delivered and installed a replacement Urine Processing Assembly in March 2009. It is tied into the station’s toilet and recovers and recycles moisture from the station’s atmosphere.

Because distillation does not normally work in space, the keg-sized distiller has to be spun to create artificial gravity. The steam collects in the centre while the contaminants move to the walls of the drum. Filters used in the system are conventional, involving coagulant chemicals and carbon.

“This is an important milestone in the development of the space station,” said Kirk Shireman, International Space Station deputy program manager at NASA’s Johnson Space Center in Houston. “This system will reduce the amount of water we must launch to the station once the shuttle retires and also test out a key technology required for sending humans on long duration missions to the moon and Mars.”

Astronauts returned samples of the recycled water to Earth, and a total of 20 litres were tested for purity at the Water & Microbiology Laboratories at Johnson. A special Space Station Program Control Board meeting on 27 April 2009 reviewed the analysis, which showed contaminants were well below established limits, and concurred that the water was safe and healthy to drink.

Space station crews will monitor the purity of the recycled water with on-board equipment and periodically send down samples for testing on Earth.

Watch the NASA video.