Solar sailing sounds cool. Solar sailing in space sounds like the kind of crazy sci-fi fantasy that would have Bill Nye busting out of his bow tie.

But it’s real! In fact, one of the first U.S. solar sails launched on NASA’s Atlas V shuttle just this morning (Japan also launched one a few years ago), and Nye himself was down in Florida to watch (don’t worry — he managed to hold on to his bow tie):

Actually, Nye wasn’t just there as a spectator. He and his colleagues at the Planetary Society, a public nonprofit space organization, have been working on project LightSail for a while. Their goal is to build lightweight spacecrafts about the size of bread loaves that propel themselves through space using 344 square-foot solar sails, rather than chemical fuel. Ultimately, the Planetary Society hopes that space sails could be a reliable, low-cost way to propel all kinds of little satellites, or CubeSats, through space.

And just to be clear — these sails are actual sails, not just solar panels. Nye and Neil deGrasse Tyson do a pretty good job explaining the science behind the sails in the video above (yes, this already cool project is also crowd-funded, and actually, they do an awesome job explaining the science, because they’re Bill Nye and Neil deGrasse Tyson). But here’s the quick and dirty: Light is composed of particles called photons. Those photons don’t have mass, but they do have momentum. And when they reflect off the shiny mylar surface of a solar sail, some of that momentum gets transferred to the sail, thus pushing it and its tiny spacecraft through space.

Today’s launch was just a test of the sail’s deployment mechanism, but the Planetary Society plans to actually put one of these puppies in orbit next year. It’ll be attached to Prox-1, a small autonomous satellite designed to inspect other spacecrafts. Prox-1 will launch on a SpaceX rocket called Falcon Heavy. (An NGO-built solar sail launching on a privately owned rocket — the future of space exploration is looking pretty interesting!)

To add to all that awesome, consider this: The project is actually the realization of an old idea that Carl Sagan was talking about way back in the ’70s. Here he is explaining solar sails to Johnny Carson:

Oh, and in case you’re interested: Atlas V also took a secret government space plane into orbit this morning. No one really knows what the plane is for, but according to The New York Times, the government promises it’s not for firing secret space weapons.