Tim Furniss/LONDON
Several crew members of the Space Shuttle STS96 Discovery became ill during a logistics supply mission and docking with the International Space Shuttle (ISS) in May but did not reveal their illness until two weeks after they landed.
Their symptoms included headaches, burning and itching eyes, flushed faces and, in one case, nausea and vomiting. Now the crew members' failure to report is giving NASA a headache of its own - it has lost the opportunity to study the possible causes of the illness, such as atmospheric problems.
The astronauts claim a right to privacy and are concerned that revelations about "collective" sickness in space could harm their prospects for future missions. The Freedom of Information Act and NASA public affairs policy, however, dictates that any illness should be reported if it affects the mission, although individuals will not be identified publicly.
Healthy feedback
When the ISS becomes operational and crews begin stays of 90 days or more on board, NASA says crew and ground team alike will be asked regularly to give feedback on crew tension, health and cohesion - a procedure that did not occur on STS96.
Dr Daniel Barry, one of the seven STS96 crew members, says the symptoms were "no big deal" although the crew was warned about possible atmosphere problems before their launch. Barry says it is impossible to know whether the symptoms were caused by stagnant air, chemical fumes or whether it was simply a prolonged case of space adaptation syndrome (SAS), a "space sickness" that well over one-third of space travellers suffer for a few days after the first onset of zero-g in orbit.
Barry, a physician, says: "I did not have a significant medical concern for the health of the crew." His own stuffy nose and headache, for example, was no different to what he experienced on his first flight.
Crew members of the STS96 mission were most affected while supporting ISS activation and stowage activity in the Russian Zarya control module and, to a lesser extent, in the US node module Unity, according to a Tiger Team report posted on the Internet by NASA Watch, an unofficial NASA watchdog.
Symptoms occurred over several days and were noted most in flight days six to eight of the nine-day mission. SAS usually strikes on days one to three, then subsides.
The onset of the symptoms did not seem to correlate to any particular event. The symptoms occurred, however, when two or more crew members were in close proximity on the Zarya for several hours.
They also occurred when crew members were working at close quarters, such as behind Zarya's panel doors and when the panel doors were left open. The crew felt better when they retreated into the Shuttle orbiter Discovery and remained there for between 10min and 2h.
The crew reported a definite odour in the Zarya, described as "musty or like a solvent". No particular concerns arose about odour in the Unity. The crew also reported that working under the floor rather than the panels of the Zarya did not seem to present the same conditions, the Tiger Team says.
The team concludes, however, that there was a real problem with the quality of the atmosphere in the ISS as configured for the STS96 mission and it was virtually impossible to quantify the specific source or cause of the illness symptoms. Preliminary results from samples taken when astronauts entered and left the ISS show no elevated levels of carbon dioxide or carbon monoxide.
Anecdotal evidence suggests that the problem resulted from a CO2-enriched atmosphere. Several crew members said their symptoms were similar to those experienced in CO2 awareness training.
The orbiter's CO2 removal systems were working properly, however. Another line of thought is that the problem could be stagnant air, coupled with a disruption of the general module air exchange, causing a disturbance in CO2 scrubbing.
Suspected outgassing may have resulted from the large amount of Velcro stuck to the walls with adhesive. Ventilation of the ISS depends on air mixing in the node to effect an exchange between the ISS modules and the orbiter. A disruption of air flow to the node prevents exchange with the orbiter. The air circulation system in the Zarya relies on the volume behind the wall panels to provide an air flow path. Opening the wall panels disrupts the flow.
Because concerns were not reported during the flight, the opportunity was lost to collect information and help to diagnose and resolve the problem. As a result, the additional work on the next ISS mission, the STS101 in January 2000, will include more local monitoring of air quality with personal monitors.
Air quality monitoring
The air quality of the Zarya - and the Zvezda module when it is attached in November - will be monitored carefully and quick solutions to the air circulation duct will be evaluated, perhaps using the Shuttle/Mir-type set-up of pushing clean air all the way to the end of the modules with the return air flowing through all the modules.
The STS96 incidents could have a long-term impact if the first crew to occupy the ISS independently of a Space Shuttle has no "safe haven" from atmospheric problems, other than the small Soyuz space ferry.
NASA concludes: "We must continue to foster an atmosphere of free exchange of information from the crew to the ground and reinforce the awareness of the significance of potential downstream impacts of an event or action in a continuously operated spacecraft."
Source: Flight International
