NASA astronaut Mike Fincke, who prompted the first medical evacuation of the International Space Station (ISM) earlier this year, has revealed that he suddenly fell ill at the station and couldn't speak in space, causing his crewmates to rush to help him. The cause of the illness, which has been ruled out by a heart attack and no apparent cause, could be related to his weightlessness and his 549 days of weightlessness. Fincoke, a retired Air Force colonel, identified himself as the sick astronaut to end public speculation. He has undergone numerous tests since returning to Earth and cannot provide any further details about his medical episode.