The master bathroom for three astronauts aboard the International Space Station is on the fritz again just days before a trio of new spaceflyers are due to launch toward the orbiting lab, NASA officials said Friday.

A temporary telemetry glitch also sent the space station into a so-called survival mode earlier this morning, changing the outpost's attitude and leading to system power downs for several hours. That issue was quickly tracked to an electronics box aboard the station, but the balky space toilet in the Russian Zvezda service module continues to plague astronauts and flight controllers.

"It failed late yesterday," NASA spokesperson John Ira Petty said of the Russian-built space commode in televised commentary from Mission Control in Houston. "Russian specialists are troubleshooting. The problem appears to be a [gas] separator issue."

It's a familiar problem for space station commander Sergei Volkov and flight engineers Oleg Kononenko and Greg Chamitoff. A similar glitch knocked the space toilet out of commission in June, leading Russian engineers to rush a spare gas-liquid separator assembly pump to NASA's Kennedy Space Center spaceport in Florida, where it was packed aboard the shuttle Discovery and launched to the orbiting laboratory.

Volkov and Kononenko resuscitated the ailing space toilet during Discovery's STS-124 mission, which also delivered the massive Japanese Kibo laboratory and ferried Chamitoff to join the Expedition 17 crew.

The space station's Russian toilet uses fans and airflow in place of gravity to collect solid and liquid waste for disposal. The gas-liquid separator is part of the liquid waste system. It weighs about 35 pounds (16 kg) and is about 1.5 feet (about half a meter) long and 8 inches (20 cm) wide and tall.

It is unclear whether there is a spare that could be added to Sunday's planned Soyuz TMA-13 launch, which will ferry space tourist Richard Garriott and two new station astronauts to the orbiting laboratory for a crew swap.

"In the meantime, the crew has been instructed to use the toilet in the Soyuz [TMA-12] spacecraft," Petty said.

NASA has paid $19 million for a second Russian-built space toilet, which will be delivered alongside other life support, exercise equipment and sleeping quarters during a November shuttle mission. Having two working main toilets is vital for the space station, which is expected to double its crew size to six astronauts next year.

Meanwhile, Petty said flight engineers in Russian and NASA's Johnson Space Center Mission Control in Houston were still working at recovering systems from this morning's telemetry glitch. While the malfunction was swiftly tracked to an electronics box, backing out of the power down process is a lengthy affair, he added.

"The back out so far has been accomplished without any damage or long term impacts to station systems," Petty said.

The station's new Expedition 18 crew is set to launch into space on Sunday, Oct. 12 at 3:01 a.m. EDT (0701 GMT). NASA will broadcast the launch live via NASA TV. Click here for SPACE.com's NASA TV feed and space station mission updates.