Currently, we do not have the technology to travel to even the closest stars. The fastest spacecraft humans have ever built is the Voyager 1, which is currently traveling at roughly 17 km/s. However, even at these speeds it would take the Voyager I nearly 70,000 years to get to the nearest star system, Alpha Centauri. Clearly, this is not even close to the speed we need to obtain to make interstellar space travel feasible. One potential way to reach speeds that would make interstellar travel feasible in an efficient matter would be with a solar sail.
(Artist rendition of a solar sail)
Solar Sails work by using the solar wind to propel an aircraft forward. Every time light hits an object, it changes the object’s momentum ever so slightly. Thus, since a stream of photons is constantly being released by the Sun in all directions, we could use giant sails attached to spacecraft in order to reflect this light and propel the spacecraft. In fact, this technique has already been used for a few satellites. By using this method, we could theoretically accelerate a spacecraft to nearly the speed of light. The only problem with this is that we would need to build a solar sail that is thousands of miles across and is thinner than a human hair. However, as technology progresses, it is certainly feasible to think that we might someday be able to achieve interstellar travel through using a solar sail.
