The Solar Sail: The Green Transportation of Tomorrow

Overall, when thinking about green transportation people's minds tend to drift towards a few key concepts: electric vehicles, biofuels, or forms of green public transportation. Since that is where the majority of today's green transportation innovation is focused you really wouldn't expect any wildly different ideas. However, every once in a while it is nice to see what might be even the most basic concepts today and envision how they could one day impact that far future of green transportation. In this case, putting the obstacle of placing a craft in orbit without currently existing technology aside, how can humanity make space travel green once we finally spread out to the stars and achieve some normalized form of space travel?

One interesting solution to that question has been introduced in the form of the solar sail: a technology that harnesses the power of light to make a journey through space seem a bit like some solar and green transportation concepts we have now. Back in May, the Japanese Aerospace Exploration Agency launched into space the very first successful solar sail spacecraft. Named IKAROS (short for Interplanetary Kite-craft Accelerated by Radiation of the Sun and perhaps as a nod to the legend of Icarus), the solar sail is currently bound, alongside a few other launched spacecraft, on a six month mission to Venus that will be used to test various technologies installed on board and to further test the strengths and weaknesses of the solar sail technology in general. Once it has reached Venus, the IKAROS will leave behind the other craft it launched with and continue on a three year journey that is intended to bring the sail around to the far side of the Sun: the very source of the energy that drives the solar sail.

While it may not be the green transportation of today, the technology itself is rather unique and many scientists believe that it could hold a great deal of promise for future space exploration and travel. The sail works by utilizing a series of reflective surfaces that bounce light particles off of it in order to harness the momentum of said particles and gain propulsion. Theoretically, it is believed that since the Sun and other light sources are giving off a continuous light, a solar sail would be able to constantly gather momentum from light particles and reach incredibly high speeds. Since the fuel source is so easily obtained and not likely to suddenly run out at any time, a solar sail could be used as a means of propelling a spacecraft almost indefinitely on a mission into deep space or in conjunction with other propulsion systems to create a sort of hybrid spacecraft.

Currently, J.A.E.A has no plans to create any manned solar sails that would bring us even closer to a future form of green transportation. However, there are plans to send more missions into space using the solar sail technology that would reach both Jupiter and the asteroids beyond Mars. Despite the fact that our ability to use solar sail technology as a method of normal transportation could be incredibly far in the future, it is incredible to simple take a moment to appreciate just how close humanity is in reaching outer space and how even amongst the stars ideas still exist that bear the stamp of green thinking.

Photo Credit: Japanese Aerospace Exploration Agency