Toxic chemical spills in space station

[stu]

An oxygen generator on the international space station overheated and spilled a toxic irritant Monday, forcing the three-man crew to don masks and gloves in the first emergency ever declared aboard the 8-year-old orbiting outpost.

 

NASA said the crew members' lives were never in any danger. They cleaned up the spill with towels. A charcoal filter scrubbed the irritant out of the air. And within a couple of hours, life aboard the station 220 miles above Earth was nearly back to normal.

 

But it was the biggest scare this smooth-running space station has had.

 

Although it paled in comparison to two fires and a collision on two previous Russian space stations and the nearly fatal explosion on Apollo 13, the incident served as a reminder of how life-and-death emergencies can come out of nowhere. It is why an emergency space capsule is always parked at the outpost in case of a sudden order to abandon ship.

 

NASA never came close to ordering the crew to leave the station, space station program manager Mike Suffredini said. But astronauts did reveal they were worried.

 

About three hours after the emergency, station commander Pavel Vinogradov tried to explain what happened to Moscow Mission Control, saying "different thoughts came to my mind." Russian flight controllers interrupted, telling him: "We were kind of nervous here, too."

 

NASA and the Russian space agency were investigating what caused the problem.

 

"We don't exactly know the nature of the spill ... but the crew is doing well," Suffredini. "It's not a life-threatening material."

 

The astronauts sounded an alarm after the equipment began smoking and turned off the ventilation system to avoid spreading any fumes from leaking drops of potassium hydroxide, which is used to power batteries.

 

Monitors showed that the cabin air was safe. "It was just an irritant issue," NASA spokesman James Hartsfield said. "The crew did exactly the right things they were trained to do."

 

It was the type of problem that is always in the back of crew members' minds, said former astronaut Jerry Linenger, who was aboard the Russian space station Mir during a 1997 fire and frequent antifreeze leaks that gave that old station a gas-station-like smell.

 

"Fumes is one of those low-level risks that sort of wears on you," Linenger said. "You realize you are in a closed ecosystem and you're breathing it. It's kind of in the back of your mind and it's hard to get out of the back of your mind. ... You're thinking this is not good."

 

The problem originated in a Russian oxygen generating machine, called an Elektron, that had been shut off for nine days while the space shuttle Atlantis was docked to the station. At about 4 a.m. EDT Monday, Russian flight controllers asked that the device be turned back on. It shut itself down and would not restart.

 

Three hours later, Moscow ordered Vinogradov to try again. A part of the machine that holds liquids overheated. It melted through a rubber seal, produced puffs of smoke, a bad smell and the release of the irritating chemical, according to NASA.

 

"The Elektron is a very fragile thing," Vinogradov later told Moscow. "It was extremely hot. ... I decided to turn it off."

 

Mission Control in Houston then asked Vinogradov to hit a red alarm button that automatically shut down the ventilation system to prevent any toxic fumes or smoke from spreading. About 7:30 a.m. EDT, Houston told the astronauts to put on surgical masks based on air-quality readings.

 

The problem caused a lingering burned-rubber smell, American astronaut Jeff Williams told Houston.

 

Potassium hydroxide, a corrosive also known as potash lye, can cause serious burns, but it has no odor, so the smell was probably caused by a burning gasket, Mission Control informed the crew.

 

The Elektron system has caused problems in the past. It had operated on and off for months before breaking down last spring. In June, the crew tried to reactivate it, with mixed results, after replacing a hydrogen vent valve outside during a spacewalk.

 

The space station has plenty of oxygen, another Elektron and other means of getting oxygen, so air will not be a problem, Suffredini said.

 

Apollo 13 commander Jim Lovell, whose lunar mission was crippled after an oxygen tank exploded, said astronauts do not fully grasp what happened until they are home.

 

"Once you're safely back on Earth, then you can look back on it with tongue in cheek and say, `Here's what I really should have done,'" Lovell said.

 

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