In order to traverse Earth's oceans, humans learned to navigate its winds and currents. As we look to our future amid the stars, solar sail technology gives us a similar opportunity: the chance to hitch a ride on light.
The concept behind the solar sail dates back to the 16th century. Famed astronomer Johannes Kepler noticed that comet tails always point away from the sun, implying that sunlight itself was pushing them around like cosmic windsocks.
Kepler suspected the presence of the solar breeze that modern spacecraft such as NASA's NanoSail-D and Japan's IKAROS sail on.
If they are, then there's not much a future in space travel. To read the rest of the article, click here.