#AtoZChallenge – Solar Sails

I get to be somewhat topical with my S entry for my Sci-Fi Themed A-to-Z Blog Challenge



Solar sails are in the news! The Planetary Society’s Lightsail 1 was deployed last year, and now there are plans to get Lightsail 2 out into space.

There was also the recent announcement of Breakthrough Starshot – a project by Yuri Milner and Stephen Hawking. This project aims to build tiny crafts with large sails and use earth-based lasers to accelerate them to 20% of the speed of light!

The earliest sci-fi reference to solar sailing was in Jules Verne’s 1865 novel From the Earth to the Moon, which came out just after James Maxwell showed that light has momentum and can exert pressure on objects. From the Earth to the Moon is also notable for its detailed description of astronauts attempting to get to the moon – a century before the Apollo program.

The idea of a solar sail is to harness the momentum of photons by deploying a light, flexible, reflective sail to capture light from the sun. A ship propelled by sunlight alone would accelerate slowly, but would also move without spending any fuel. This means that solar sailing craft are cheap, and can operate for very long times.

That’s why the recent announcement by Hawking has such great potential – all of the needed technology exists now, and the project wouldn’t cost that much. If it goes through, we might just see some footage from another solar system within the next 20 years!

More about solar sails: