LightSail Program Status: One Down, One to Go

The LightSail program involves two 3U CubeSats designed to advance solar sailing technology state of the art. The entire program is privately funded by members and supporters of The Planetary Society, the world’s largest nonprofit space advocacy organization. Spacecraft design started in 2009; by the end of 2011 both spacecraft had largely been built but not fully tested, and neither had a firm launch commitment. Following an 18-month program pause during 2012-2013, the effort was resumed after launch opportunities had been secured for each spacecraft. The first LightSail spacecraft—dedicated primarily to demonstrating the solar sail deployment process—was launched into Earth orbit on 2015 May 20 as a secondary payload aboard an Atlas 5 rocket, and on June 9 mission success was declared. The mission plan for the second LightSail includes demonstration of solar sailing in Earth orbit, among other objectives. It is on track for a launch in 2016 aboard a Falcon Heavy rocket as a key element of the Prox-1 mission. Lessons learned from the 2015 test mission will be applied to the 2016 mission, and lessons from both LightSail missions will inform planned NASA solar sail-based CubeSat missions and hopefully enhance their chances for mission success.