10 Most Important Scientific Discoveries Of 2019

The concept of a solar sail was first described in 1610 in a letter from Johannes Kepler to Galileo. In the letter, he wrote about an idea to "Provide ships or sails adapted to the heavenly breezes, and there will be some who will brave even that void."

The idea revolved around the concept of solar pressure, which is captured by large reflective sheets or sails to achieve a constant, energy independent thrust. The Planetary Society, under the direction of famed engineer and science advocate Bill Nye, launched a crowdfunding campaign to bring Kepler's idea to a reality, and in June 2019, they succeeded.

LightSail 2 was launched on 25 June 2019 into Earth's orbit, and after successfully deploying its sail, its orbit was raised a significant and measurable amount, proving the solar sail technology was viable and effective. The first LightSail was launched to test the concept but didn't deploy a sail, so this was a first in spaceflight.

Now that the concept has been tested and proven, work is being done to refine it further. It may be possible to construct inexpensive LightSails to one day propel supplies and equipment from Earth to distant outposts on Mars, the asteroid belt, and beyond.