Carl Sagan once proposed the idea of sailing through the cosmos via a solar-powered spacecraft. This spaceship would use sunlight radiation to power its flight much like a boat uses the wind for propellant. On May 20th, the Sagan co-founded Planetary Society will initiate its first test flight for such a solar vehicle: the LightSail.
When the LightSail deploys, it won’t be high enough into orbit to harvest the Sun’s energy. Instead, this test flight will attempt to see if it can successfully unfurl its Mylar sails. If all goes well, this will set a precedent for an actual space test in 2016.
This isn’t the first solar-powered vessel, however. Japan launched the IKAROS probe in July of 2010. Soon after IKAROS, NASA launched their own version, the NanoSail-D. However, what we’ve been seeing in the realm of space travel is a shift towards private enterprise, and if the LightSail is successful it could prove very important since the program costs just 4.5 million–a small sum compared to the typical space travel budget.
With no expensive and heavy fuels to rely on, the LightSail would make space exploration more practical as well as allowing for longer trips with smaller vessels.