INTERNATIONAL SPACE STATION -- Astronauts at the International Space Station have a busy day Friday, even though they will only be working a half-day.
They will be working on a system that recycles urine into drinking water. Find out more about the water recycler.
The astronauts will also fire the thrusters on the shuttle Endeavour to boost the space station's orbit.
Then, after the astronauts hold a press conference, they'll get the rest of the day off.
Endeavour's seven astronauts and the three space station crew members have been working without a break, including two spacewalks, the latest of which was Thursday. The orbit boost will put the space station at the right altitude to receive a Russian Progress cargo spaceship.
The recycling system reclaims urine and sweat and turns it into drinkable water, essential when the station takes on three
additional residents. A combustion alarm delayed a test yesterday but flight controllers think it's a false alarm.
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