According to NASA spokesman Jay Bolden, who spoke with Space.com, the Americans living aboard the International Space Station are able to cast their ballots in Tuesday's election with a little help from the people in Mission Control.
"They send [their digital ballot] back to Mission Control," Bolden said. It's a secure ballot that is then sent directly to the voting authorities."
American commander Sunita Williams and flight engineer Kevin Ford are two of the six people currently speeding around the Earth at more than 17,000 miles per minute. As it happens, both were able to vote absentee from a significantly more conventional location--Russia--before they launched for space.
The system was put in place for orbital voting in 1997, thanks to a bill passed by Texas legislators. Nearly all NASA's astronauts live near Houston, Texas, where the Johnson Space Center (and Mission Control) is located.
The first person to vote from pace was David Wolf, participating in a 1997 local election. Leroy Chiao became the first American to vote in a presidential election from space in 2004.