Tuesday Nov. 6 is election day, and for millions of Americans that means braving lines at a local polling place to help decide who will be the next commander in chief. But what happens when you're stuck in space hundreds of miles above Earth? Do astronauts floating around in zero-gravity still get a say in the country's future? It turns out they do. For several years now, adventurers aboard the International Space Station (ISS) have been able to cast their votes via encrypted email. Here's how it works:

How do astronauts vote?
Thanks to a 1997 bill passed in the state of Texas, where nearly all NASA astronauts live, registered voters can digitally beam their ballots back down to Houston. After filling out the form, "they send it back to Mission Control," says NASA spokesman Jay Bolden. "It's a secure ballot that is then sent directly to the voting authorities." Come to think of it, says Mike Wall at Space.com, it's kind of the "ultimate absentee ballot."

Are any Americans currently in space?
Yes, two Americans are among the six-person crew on the ISS. They won't, however, be sending in their votes tomorrow. Commander Sunita Williams — whom you may remember as the woman who completed a triathlon in space — and flight engineer Kevin Ford already fulfilled their duties as U.S. citizens, casting their votes while stationed in Russia before launch. (No word on how they voted.)

But astronauts have cast their ballots from orbit before?
When the 1997 Texas bill was passed, David Wolf, then aboard Russia's Mir space station, became the first astronaut to file his vote from space via encrypted email. Wolf, however, was voting in a local election. It wasn't until October 2004 that Leroy Chiao, then stuck aboard the ISS, became the first far-flung astronaut to vote for a president. And if an astronaut can do it, says Jennifer Lawinski at The Stir, "there's no good reason the rest of us can't find a way to make it to the polls."

Sources: How To Geek, Space.comThe Stir