Yes But you are not likely to go for a 5K run on a space station -2001 movie aside-. I've had clients that were elderly, very much the armchair astronauts and sedentary, that have said their automatics did not work . But after a day of wear on my wrist and moving around ,fighting gravity, everything worked well.I would bet the bag of M&Ms the power reserve would be less than on earth and the winder boxes would not work . Gravity holds the rotor in place as the watch moves around . The rotor's inertia would have to overcome the friction of the bearing and winding spring . I guess you can always tell the NASA automatic guys , they are the ones violently shaking their wrists.That and the digital quartz Seiko on the other wrist like with H. Furrer.

: There is a mistaken perception that a rotor
: won't work outside of a major gravitational
: field (in zero or near-zero gravity). But, a
: rotor operates on inertia, not gravity, and
: as a result a rotor does work in such
: environments and will wind themselves.

: -- Chuck