The solar sail is a relatively simple and elegant propulsion method, as it does not require a complex engine or the ability to carry fuel onboard the spacecraft. The solar sail moves due to solar radiation pressure, which is basically photons of light striking the solar sail being reflected, and as a result exchanging their momentum with the highly reflective sail.

After observing comets and the appearance of what looked to be tails, Johannes Kepler proposed that comet tails were particles that were swept out by sunlight pressure on the comet. The presence of light pressure was proved in theory by Maxwell in 1873 and verified by Lebedew a quarter century later in Russia. Konstantin Tsiolkovsky and Fridrickh Tsander proposed the concept of using large mirrors of very thin sheets as a means of accelerating spacecraft in the 1920's but the concept remained pretty much dormant until the 1950's.

In 1951, Carl Wiley published an article in a fiction magazine while writing under a pseudonym so as not to lose credibility in his field, for a feasible solar sail design. Seven years later, Richard Garwin published the first western technical paper on solar sailing (and coined the term in the process). In the 1970's NASA's Jet Propulsion Laboratory began an in depth study of the solar sail for a Halley's Comet rendezvous mission. The solar sail eventually lost out to solar electric propulsion due to time constraints and political considerations, but the mission was later scrapped, and neither option was flown.

Solar sails are evolving into a promising form of interplanetary flight that has received renewed interest and funding in the last few years.  It is also exciting that this field may be preparing for a technological explosion as new sail materials become available for use and solar sailing technologies mature. For these reasons, we have chosen to design a solar sail as our fourth year engineering project.