Solar Sail Technology, the Dream of the Planetary Society, Is One Step Closer to Becoming a Reality

Tuesday afternoon Lightsail 2, a spacecraft the size of a loaf of bread, unfolded and transformed into a 32-square-meter solar sail. The small spacecraft and its mission are the current culmination of decades of impassioned work and research by the Planetary Society. The society, founded by Carl Sagan and other renowned astrophysicists Louis Friedman and Bruce Murray, aims to push the limits of space exploration. Lightsail 2 seeks to prove that solar sail technology is an effective option when it comes to deep space propulsion.

SAIL DEPLOYMENT COMPLETE! We're sailing on SUNLIGHT!!!!! pic.twitter.com/PA74NMa7Ry — Planetary Society (@exploreplanets) July 23, 2019

This isn’t your typical solar power, though. A solar sail doesn’t generate electricity. It’s a whole different type of Voodoo magic science that is really cool!

Solar Sail Technology: How it Works

As the video states, traditionally, we’ve relied on rocket fuel to get us where we need to go in space. And, for now, at least, we still need those methods to get to space. But once we’re up there, rockets are really inefficient. Solar sail technology works by using an ultra-light and ultra-thin sheet of reflective material to capture the energy of billions and billions of photons. On its own, a single photon – being without mass – has very little momentum. However, just like the brilliant theory in Mike Judge’s classic Office Space, all of those little “pennies” of momentum add up to a lot of energy.

The real beauty of the solar sail idea, however, lies in continuous acceleration. A solar sail will continue to pick up speed until it can’t find any more photons. Okay, it’s not “hyperspace,” “maximum warp” or “ludicrous speed.” However, it seems like a really good option for getting to faraway places. Lightsail 2 isn’t the first successful test of the solar sail concept. Both NASA and JAXA (the Japan Aerospace Exploration Agency) have successfully tested their own versions of the solar sail concept. Those tests were nearly a decade ago, however.

With the new space race heating up and so much focus on the Moon and Mars, it’s nice to know that Bill Nye and the folks at the Planetary Society are still holding to their mission. Sagan and the others formed the society in an effort to detach space exploration from politics. In this regard, the Lightsail 2 Deployment is a major win for that mission.