Oxygen generator problem triggers station alarm
BY WILLIAM HARWOOD
STORY WRITTEN FOR CBS NEWS "SPACE PLACE" & USED WITH PERMISSION
Posted: September 18, 2006; Updated at 9:35 a.m. EDT
The space station astronauts activated a smoke alarm in the Russian segment of the international space station this morning when fumes from an oxygen generator triggered momentary fear about a possible fire. Flight engineer Jeff Williams reported an unusual smell, possibly from an overheated rubber gasket in the Elektron oxygen generation system, but officials said there was no fire and the crew was not in any danger.
As events developed, NASA flight controllers formally declared a spacecraft emergency to ensure priority communications through the agency's communications satellite network, but there was no immediate threat to the astronauts.
Space station Program Manager Mike Suffredini said the crew never donned gas masks, but as a precaution, Expedition 13 commander Pavel Vinogradov, Williams and European Space Agency astronaut Thomas Reiter put on surgical gloves and masks to prevent contact with any contaminants.
"The crew reported at first smoke in the cabin and a smell," Suffredini said. "They discussed a leak at the oxygen vent. It turns out what was happening is we were having some sort of a leak of potassium hydroxide that's coming out of the O2 vent. We've shut down the Elektron and cleaned up the spill.
"There was never any smoke in the cabin. KOH is what we refer to as a 'tox-2' material, it's an irritant. ... The crew's doing very well. We don't quite know the nature of the spill, we'll have plenty of time to work through that. It's a stable situation, in fact all the readings ... indicate all the constituents we're concerned about have stayed very, very low. Things look very stable on board."
Potassium hydroxide is odorless, officials said, and the smell reported by Williams more likely was associated with an over-heated rubber gasket in the Elektron system.
In any case, the station's ventilation system was shut down to prevent the spread of smoke or contaminants through the rest of the lab complex. A charcoal air filter was put in place to help scrub the atmosphere of any lingering potassium hydroxide fumes.
The problem developed shortly after 7 a.m.
"We would like to have any words you might have on the concentration of smoke, whether it's increasing, decreasing." astronaut Shannon Lucid called from mission control in Houston.
"I would say the situation is stable right now," Williams replied around 7:45 a.m.. "There's an obvious smell, and it's stable. There was never any smoke, there was a smell and it was perhaps wrongly assumed to be a fire initially. Turned out to be this toxic atmospheric release."
"OK Jeff, we copy. There was not a fire, it was just this toxic liquid that was coming out."
"The reason we assumed a fire right away is ... the Elektron was very hot," Williams said.
Later, Williams called down and asked mission control to let his wife know he was not in any danger.
"Hey Shannon, could you get hold of Steve Gilmore and ask him to give a call to the house and explain what's going on ... so they find out that way and not another way?" Williams asked.
"And Jeff, that has already been taken care of," Lucid replied.
"OK, thank you."
The Elektron generates oxygen by using electricty to break water down into its atomic components. The oxygen goes into the station's air supply while the hydrogen is dumped overboard. The Elektron provides the bulk of the oxygen used by the entire station crew.
But the complex also is equipped with so-called "candles" that can generate oxygen through a different type of chemical reaction and some 90 pounds of oxygen is available in tanks attached to the U.S. Quest airlock module. The station typically has enough supplies on board to provide oxygen for a month or more regardless of the health of the Elektron.
The cause of today's problem is not yet known, or whether the Elektron can be restarted. Spare Elektron components are on board if repairs are required but the Russians have a mixed record when it comes to performing in-flight maintenance on the complex devices.
Two new space station crew members, along with a space tourist, were launched earlier today from Kazakhstan aboard a Soyuz spacecraft. They are scheduled to dock Wednesday, boosting the station's crew to six. Suffredini said today's incident will not affect those plans.
Outgoing commander Pavel Vinogradov, flight engineer Williams and the space tourist, Anousheh Ansari, are scheduled return to Earth Sept. 28 aboard the Soyuz TMA-8 spacecraft. Expedition 14 commander Mike Lopez-Alegria, flight engineer Mikhail Tyurin and Reiter, who was launched to the station in July aboard the shuttle Discovery, will remain aboard the complex.
Even if the Elektron cannot be immediately restarted, the station has more than enough stored oxygen and oxygen-generation candles on board to easily support the combined crews and the three Expedition 14 crew members once the TMA-8 undocks for return to Earth.
"If we don't ever recover the Elektron, then O2 typically would be our limiting consumable," Suffredini said in an interview. "But that's not remotely a concern for the near term, absolutely not."