A news report says some U.S. space agency scientists had opposed sending a fresh crew to the international space station because faulty environmental monitoring equipment aboard could pose a health threat. But the crew of the orbiting outpost says no such threat exists at the moment.
The Washington Post newspaper says two NASA officials responsible for space station health and environmental conditions strenuously objected to Saturday's launch of a replacement space station crew.
The news account says that before astronaut Michael Foale and cosmonaut Alexander Kaleri lifted-off on a Soyuz craft from Kazakhstan, the unidentified officials had warned of continued degradation of station equipment that monitors air and water quality. They reportedly said that the grounding of U.S. space shuttles after February's Columbia disaster made it impossible to replace or repair the faulty hardware.
A NASA spokesman says middle-level engineers and management held a full discussion about the issues and concluded that the technical problems were not beyond the agency's safety standards.
In a news briefing from the station, astronaut Foale agreed. "Actually, it is the normal process of thinking about what can go wrong, discussing it, and then making sure it does not go wrong," he said.
Mr. Foale says the two dissenting NASA officials had explained to him they had no reason to believe air and water quality on the space station was actually dangerous. He says they wanted to focus attention on the issue to ensure that the crew and ground controllers monitored the station environment closely.
According to the Washington Post, the NASA medical officials said the monitoring equipment has been troublesome for the past year, causing station crews to complain of headaches and dizziness.
But astronaut Ed Lu, whom Michael Foale is replacing, says he and his Russian teammate, Yuri Malenchenko, have had no medical problems during their six-month stay on the outpost. He describes the press account as exaggerated.
"Right now, the conditions are good here. The problem is not that the conditions are not good, but that we can not verify that things will continue to be good over the very long term. That is what people are concerned about," he said.
Michael Foale says the station environmental monitoring equipment accurately measures levels of important gases such as oxygen and nitrogen and carbon dioxide. The problem is that it cannot verify trace contaminants that might be poisonous, such as carbon monoxide or dangerous microbes in the water.
"The contaminants, the poisonous substances about which we are worried, have not been detected and they are not very common aboard the space station," he said. "We would have to have a fire, for example, or a very extraordinary substance brought on board by a new load of cargo to introduce those things into the space station environment."
Mr. Foale says that if the air and water monitoring systems aboard the station were to fail, similar equipment aboard the attached Soyuz escape vehicle could substitute.
Despite the moratorium on shuttle flights to the station, the U.S. and Russian space agencies decided to keep the outpost occupied with a smaller, two-person crew. NASA officials say that keeping a crew aboard is the best way of maintaining the outpost in minimum working condition until shuttles return to flight.