“Honey, the toilet’s on the fritz again! I’ll call the plumber.”

Sounds easy, doesn’t it? Unless the toilet is 217 miles above the earth--a little outside the range of your standard house call.

This is the current situation aboard the International Space Station. The usual crew complement of three space travelers share one small bathroom, its toilet equipped with appropriate funnel connections to allow a near-normal elimination experience in zero-gravity.

The specialized equipment, now seven years old, started malfunctioning last week, and while the solid waste collection unit is still working, the fan for the liquid waste collector has stopped.

  As the zero-gee system is run using air flow, having a fan that won’t suck air through the unit brings the workings to a halt.

Astro- and cosmonauts have been able to use the facilities in the Soyuz craft attached to the station to use as an escape vehicle in emergency, but those facilities are not designed for full-time use. Instead, the crew is making do with homegrown solutions, plastic bags and a lot of prayer.

The previously-scheduled mission of the shuttle Discovery, set to launch Saturday just after 5 p.m., will now include delivery of replacement toilet parts shipped all the way from Russia.

A second full toilet unit is scheduled to be delivered in late 2008, to make the space station a two-seater, at a cost of $19 million, to accommodate the expansion of the space station to six residents instead of three.