The astronaut who prompted NASA’s first medical evacuation earlier this year says doctors still don’t know why he suddenly fell sick at the International Space Station. Four-time space flier Mike Fincke said in an interview with The Associated Press on Friday that he was eating dinner after prepping for a spacewalk the next day when he went into distress. He couldn’t talk and remembers no pain. The medical episode lasted 20 minutes and he felt fine afterward. The 59-year-old Fincke says doctors have ruled out a heart attack, he wasn’t choking, but everything else is on the table and could be related to his 549 days of weightlessness.