Almost forty years ago, legendary astronomer Carl Sagan unveiled plans for a spacecraft with large ‘sails’ that rides solar winds across the universe in much the same way as a sailboat glides over the ocean. Now, decades later, The Planetary Society (the organization Sagan founded, which is currently headed up by Bill Nye) is set to launch the very first test flight of this technology. The solar-powered spaceship is called the LightSail, and many hope that it will usher in an age of more affordable space exploration.

The LightSail is designed to be launched in several “CubeSats” – tiny spacecraft that hitch rides aboard bigger vehicles. The stack of three dinky CubeSats that make up the LightSail have a total size of 30x10x10cm, and they feature solar panels along their sides. Once in space, four arms unfurl from the LightSail to unfold four large triangular mylar sails, each one just 4.5 microns thick.

And that’s when things get very clever. The Planetary Society explains: “As light reflects off a sail, most of its momentum is transferred, pushing on the sail. The resulting acceleration is small, but continuous. Unlike chemical rockets that provide short bursts of thrust, solar sails thrust continuously and can reach higher speeds over time.”

The first test will take place on May 30 when the LightSail is carried out into orbit on an Atlas V rocket. As The Planetary Society explains, “We won’t fly high enough above the Earth’s atmosphere for solar sailing, but we’ll test our sail deployment sequence and snap some pretty pictures.” And if all goes well with that test, then the LightSail will hitch a ride aboard a SpaceX-built Falcon Heavy rocket for a full test of the technology.

The entire program is predicted to cost just $4.5 million – mere pocket change in the world of space exploration – while avoiding the need for heavy, unsustainable fuels. If you want to get a peek at the sail, The Planetary Society will soon be announcing viewing locations for the May 30 flight.

+ The Planetary Society

Via The Verge