LightSail could solve some issues with chemically powered flight

Satellites are one of mankind’s most powerful tools for expanding scientific knowledge, but they have a limitation: Directing them anywhere other than an involuntary orbit requires external power, which eventually runs out. Now, the Planetary Society (led by CEO Bill Nye) intends to launch LightSail, a craft that’s propelled by photons emitted by the sun.

“This is a more accessible, easier-to-build gizmo,” Nye told the New York times. “You don’t need a whole space agency.”

Though it sounds far-fetched, photons may lack mass, but they do have enough energy when traveling in packs to produce momentum. LightSail intends to attach three small modules known as CubeSats, which measure about 10 centimeters square, to a comparatively enormous (32 square meters) solar sail that will power it around the solar system. The concept gets its first test in May, when it’s launched skyward aboard an Atlas V rocket.

Sadly, no solar sailing will take place during May’s maiden voyage. For now, their intention is only to unfurl LightSail’s solar sail to ensure the process works as designed. Deployed via metallic booms that the creators liken to tape measures, the sail should be visible from Earth. The CubeSat module also includes electromagnetic rods to orient it with regards to Earth. Ground-based lasers will allow operators to determine the effect of sunlight on the solar sail.

Unlike chemical rockets that produce a finite amount of thrust, the constant bombardment by photons has the potential to build considerable momentum over time. Because space is a vacuum, LightSail should only gain speed barring any collisions.

If all goes well in May, the next launch will come in 2016, when it will be launched inside satellite Prox-1, carried aboard SpaceX’s Falcon Heavy rocket. Once it clears Earth’s atmosphere, Prox-1 will eject LightSail into empty space (along with taking pictures to document the occasion). Later, Prox-1 will rendezvous with LightSail for inspection.

“We strongly believe this could be a big part of the future of interplanetary missions,” Nye said. “It will ultimately eventually take a lot of missions a long, long way.”