Washington  - Astronauts on the International Space Station were told Wednesday that they can now drink water recycled from urine and sweat by a purifying machine.

The move is critical to the planned expansion of the ISS crew from three to six people.

The Urine Processing Assembly was first installed in November on the ISS, but a glitch prompted US space agency NASA to install a replacement on a later space shuttle flight in March. Samples were sent back to Earth for testing and met standards for safe drinking water.

NASA said that the ISS's Russian commander, Gennady Padalka, US astronaut Mike Barratt and Japanese astronaut Koichi Wakata greeted the news with a toast of the high-tech water aboard the orbiting space station.

"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," Barratt said. "We're really happy for this day and for the team that put this together. This is the kind of technology that will get us to the moon and further."

On May 27, a Russian Soyuz spacecraft will carry three more astronauts to the station. Unlike in the past, they will not be replacing those currently on board but will join three astronauts already there to double the size of the crew.

It will be the first time each of the five partner space agencies - from the US, Russia, Japan, Europe and Canada - will have crew members living together on ISS. (dpa)