The Planetary Society’s citizen-funded LightSail 2 solar-propelled spacecraft is set to launch on June 22 on board a SpaceX Falcon Heavy. It will attempt the first controlled solar sail flight in Earth orbit. LightSail 1 successfully completed its test flight mission in 2015. LightSail® is aimed at testing “solar sailing” technology for CubeSats, which comprise many Amateur Radio satellites. According to the Planetary Society, solar sailing uses reflective sails to harness the momentum of sunlight for propulsion. “One disadvantage to CubeSats is that they typically lack propulsion, which limits their range of applications,” The Planetary Society says. “LightSail will demonstrate the viability of using solar sailing for CubeSats.”
Scientific collaboration between The Planetary Society and Russia led to the creation of Cosmos 1, a solar sail spacecraft launched aboard a repurposed ICBM. But test flights in 2001 and 2005 failed due to problems with the launch vehicle. The first successful solar sail was launched by Japan in 2010, when the IKAROS spacecraft was deployed from a Venus-bound space probe.
NASA has looked into using solar sails to de-orbit CubeSats with atmospheric drag, and its Nanosail-D2 mission in 2010 was successful. The Planetary Society’s LightSail program was initiated a year earlier. It aimed to construct a CubeSat similar to Nanosail-D that would demonstrate true solar sailing. LightSail 1 snagged a slot aboard an Atlas V launch in 2015, but the target orbit was not high enough for solar sailing thrust to overcome atmospheric drag. The Planetary Society accepted the free ride anyway and successfully tested the spacecraft’s sail deployment mechanism.
LightSail 2 will be enclosed within Prox-1, a Georgia Tech student-built spacecraft the size of a small washing machine. Prox-1 will detach from the Falcon Heavy into a circular 720-kilometer orbit. A week later, it will deploy LightSail 2