Astronauts try to work out kinks in urine machine

HOUSTON (AP) - Astronauts are hoping the solution to fixing a water recycling system on the space station is a relatively simple one.

Flight controllers here on Earth are going to have them change the way a centrifuge is mounted in the $154 million system.

For the last three-days they've been trying to get the system running so it can generate samples for testing back on Earth.

But so far the system will only run for two hours before shutting down.

The space station is supposed to double the size of its crew next year, but that can't happen until tests show the water system is working right.

Otherwise, astronauts have part of today off. The fourth and final spacewalk is set for tomorrow.

Mission managers have decided not to extend the mission by an extra day since the astronauts have collected enough water samples.

Endeavour is scheduled to undock on Thanksgiving.

(Copyright 2008 by The Associated Press. All Rights Reserved.) AP-NY-11-23-08 1506EST