It seems improbable if not impossible: an astronaut with PD had not only been certified for space flight, but had also been certified to perform a planned space walk on the MIR space station. That morning, as I began the ascent into orbit to rendezvous with the MIR, I thought about my own personal journey leading up to that moment. It was as hard as any I’d ever faced, but one that I had never given up on. A journey that had begun almost two years earlier.

My second mission had been STS-59 in April 1994 and it was very successful. I felt completely fit during and after the flight. About six months later I went in for my annual flight physical. Everything, including my standard neurological exam, was satisfactory. Just as a favor, I asked the flight surgeon after the exam if I could have an orthopedic surgeon look at my right shoulder. (I played competitive racquetball and thought I might have recently injured it during a game). He asked me where it hurt and I told him it didn’t hurt at all. Rather, my right arm just seemed to hang without moving when I walked. I could tell I [...] continue the story