The Russian-built toilet was installed in Nov. 2008. It was determined that the pump separator had flooded.
Houston- and Moscow-based specialists are discussing the problem. Astronauts Frank De Winne (Belgium) and Michael Barratt (U.S.), as the AP reports, "ripped apart the compartment, working well into the evening. Mission Control finally instructed them to call it a day and resume the effort Monday morning."
In the meantime, Endeavour's seven-person crew will use their shuttle's bathroom. If the bathroom is used for an extended period of time, however, the shuttle's waste water tank could fill up. The water cannot be ejected because Endeavour is docked, with its waste water nozzle pointing at the Space Station's external lab equipment.
The six astronauts aboard the International Space Station will rely on the one remaining station commode.
Flight director Brian Smith declined to speculate whether overuse caused the toilet trouble....Smith said there is no urgency to the bathroom situation, at least for now. But he said if the toilet remains out of action for several days, "then we'll readdress the situation and see what we have to do."
Additionally, urine collection bags are available.