A non-profit that promotes space exploration – The Planetary Society – has proposed to launch two small crafts to solar-sail around May this year, tagging along with other small satellites on an Atlas 5 rocket. This is demonstrating that sailing on the wings of sunlight is possible through technology developed by space scientists.

“We strongly believe this could be a big part of the future of interplanetary missions,” said William Sanford Nye, the chief executive of the organization. “It will ultimately eventually take a lot of missions a long, long way.”

Since photons or light particles have been found to reflect from bright surfaces, they appear to provide speed and momentum to space objects as established by equations of electromagnetism published by the physicist James Clerk Maxwell in the 1860s. Jules Verne appears to have been the first to realize that this force could be harnessed for space travel through his 1865 novel From the Earth to the Moon.

LightSail is about the size of a loaf of bread – 4 inches by 4 inches by 1 foot. In orbit, the spacecraft will undergo a month of testing before it extends four 13-foot-long booms and unfurls four triangular pieces of Mylar, less than 1/5,000th of an inch thick, to form a square sail that spans almost 345 square feet.

A second LightSail is planned for launch next year by being lofted by the Falcon Heavy rocket from SpaceX at an altitude of 450 miles; this particular flight will be the first to show controlled solar sailing while in orbit around Earth.

“The idea ultimately is to be able to tack like a sailboat on each orbit,” said Mr. Nye. Both LightSails were built for less than $4 million, he added.