Crewmembers of Space Shuttle Discovery/STS96, which docked with the International Space Station (ISS) in May, suffered headaches, irritated eyes, nausea and vomiting inside the Russian Zarya control module, possibly caused by the build-up of excess carbon dioxide.

The symptoms, which subsided when the crew returned to the Shuttle orbiter cabin, are believed to be related to circulation between the Shuttle and the connecting modules, which comprise the Zarya and the US Unity node.

The crew did not report the symptoms until after landing, raising concerns about crew ethics and relations with ground teams during operational shifts. Immediate confidential medical status reports to mission control could have allowed engineers to resolve the problem.

US crews have been reticent about health issues in orbit for fear of curtailing missions or affecting their chances of flying other ones. This has strained relations with ground-based medical teams. This issue will have to be clearly defined before ISS occupation begins next March. Crews will be without a "safe haven" orbiter, although the Soyuz emergency return vehicle will be on hand.

NASA says it will ensure that better atmosphere monitoring devices are carried on the next scheduled mission - STS101/Atlantis to the ISS in December.

Source: Flight International