45 reactions | Where you can travel in space depends on how much propellant you’ve got on board your rocket and how efficiently you can use it. But there’s a source of free propellant right here in the Solar System - the Sun - which is streaming out photons in all directions. You just need to catch them. And right now, the Planetary Society’s new LightSail 2 spacecraft is testing out just how well it’ll work. | Universe Today | Facebook