According to the Harris County Clerk's Office in Texas, USA, astronauts Butch Wilmore, Sunita Williams, and Don Pettit participated in early voting for the U.S. presidential election aboard the International Space Station. NASA astronauts posted a photo on Instagram on election day wearing socks featuring elements of the American flag. Two of the astronauts' socks had the phrase 'Proud to be an American' written on them. How do astronauts vote? Ballots in space are transmitted to Earth in the same way data is sent between the space station and mission control, transmitted to Earth via NASA's Near Space Network.