How does a solar sail work?

A solar sail is a spacecraft propulsion method that uses radiation pressure exerted by sunlight on large mirrors or reflecting surfaces. It works based on the principle of momentum transfer through the photons in sunlight. The spacecraft consists of a large, thin, reflective sail that is used to harness the momentum of photons in sunlight.

When sunlight hits the sail, it transfers a small amount of momentum to the sail, which results in the spacecraft gaining speed. Since the force generated is small, the sail has to be very large in order to generate enough thrust to propel the spacecraft. The size of the sail can range from a few meters to several kilometers across.

One of the advantages of a solar sail is that it does not require any fuel, as it uses sunlight to generate thrust. This makes it an attractive propulsion method for long-duration space missions, such as interstellar travel, where refueling is not possible.

Solar sails have been proposed for a number of space missions, including interplanetary travel, solar polar missions, and even missions to other stars. Although still in their early stages of development, solar sails represent a promising technology for space exploration and could revolutionize the way we travel through the solar system and beyond.