We got word yesterday that the crowdfunded LightSail 2 spacecraft had successfully deployed its Mylar solar sail, a large sheet of reflective material that will harness the minute power of photons bouncing off its surface to make an energy-efficient traversal through space. But that was based on data transmitted by the spacecraft. Now we have photographic proof thanks to new images sent by LightSail 2 when it was within communication range of a ground station.
These images, and the animated GIF created from a sequence of those captured by the spacecraft’s onboard fisheye cameras, show the boxing-ring-sized Mylar sail unfurling — with the GIF sped up about 100 times versus how long it actually took for the sail to fully deploy and spread out. This is a key milestone, and one the original LightSail never actually accomplished. Now, the mission will continue as LightSail 2 attempts to demonstrate that CubeSats can successfully propel themselves using solar sails, which will have big benefits in terms of cost of operation and accessibility of space research.
The spacecraft launched aboard a Falcon Heavy mission in June, and was built by a team of Georgia Tech students. It underwent extensive pre-deployment testing leading up to this moment, and already data returned shows that it’s being propelled by the force of the sun striking the sail, which is roughly equivalent to “the weight of a paperclip,” according to The Planetary Society. That small amount of force will accumulate over time and, eventually, if all goes to plan, will raise LightSail 2’s current orbit and demonstrate viability of this propulsion method for small sat use.