Solar Sailing: A Reality

Ikaros in space

7.5 million km from Earth, a 200 square meter wide contraption of metal and solar cells unfurls, propelled through space by no more than the rays of sun lighting its back. Sound like fiction? Think again.

On 3rd June, 2010, Japan deployed Ikaros, the first ever solar sail to travel into space. On 10th June it was confirmed that it had successfully unfurled and begun generating power.

Think of it as a large spinning disk, with a paper-thin surface collecting energy. Before deployment the disk was wound up, carried into space as a payload by Akatsuki (Japan’s Venus Orbiter) and remained in its wound state until it was released on the 3rd.

Ikaros is an exploratory device whose official purpose is to confirm suspicions about the existence of lightning and active volcanoes on Venus. More importantly than any single purpose, however, it is pioneering a new type of space travel. Louis Friedman of The Planetary Society recently called it, “the future of interstellar travel.”

‘Solar sailing’, as it has been deemed, works through photons falling on a thin, reflective surface and exerting pressure. This pressure pushes the craft along. It is not expected to replace conventional (chemical) propulsion systems – the amount of energy generated is too small. But it does have advantages: although the amount of energy generated is small, it is also continuous – as long as the sun remains within a reasonable distance, it will not ‘run out’. Additionally, it allows for a light-weight space-craft which has the potential to greatly cut the costs of space travel and allow movement at much faster speeds than ordinary crafts.

There are still many trials ahead. The primary concerns of developers are that the membrane (body of the device) is not damaged and that the ‘drivers’ can retain control of it.

If all goes well, Ikaros will reach Venus sometime in December – carrying with it the hopes and dreams of scientists and sci-fi lovers everywhere.


Update: As of Dec 8th 2010, Ikaros has succesfully completed its mission. It has passed Venus and is continuing to travel in order to allow the 'drivers' practice at controlling it. More solar sail experiments are planned, including branching into solar satellites. Read more here: http://www.jspec.jaxa.jp/e/activity/ikaros.html