Pekka Janhunen's Electric Solar Sail

We here at Olivia Waite may have spent our academic life wading through the humanities, but we've got a soft spot for science as well. Even—especially!—the sciences we don't understand. Just ask our college physics professor, poor man. One of our favorite subjects is space—NASA, moon landings, science fiction, anti-gravity, constellations, all that good stuff. We even watched a few episodes of Ancient Aliens before we had to stop because we were yelling at the tv hard enough to break something. (The entire show can be boiled down to that moment in The Core when Aaron Eckhart says the entire premise of this movie couldn't even happen, and megadouche Stanley Tucci cocks an eyebrow and says, despite all logic and reason: "But what if we could?")

And today, idly doing research along the interlinked pages of Wikipedia, we found out about the beautiful, simple, mind-boggling genius of Pekka Janhunen's electric solar sail.

A simple black-and-white line diagram of how the electronic solar sail is designed to work.A primer: the sun is constantly throwing off a stream of positively charged ions in a stream we call solar wind. Regular solar sails are very thin metal or mirrors; because there is no atmosphere in space, the ions push against the thin material of the sail and create force, propelling the spacecraft forward.

So basically: you're sailing on light instead of on wind as Earthbound sailboats do.

As if this were not awesome enough, Pekka Janhunen (hän on suomalainen!) has taken it one step further: his electric solar sail is not a large sheet of material—instead, his design uses a number of long, thin wires tethered to the spacecraft and flowering outward. Electrons are pulled from the wires and fired away using an electron gun, which means the wires themselves are positively charged, which in turn means they repel the ions in the solar wind. Because of the electrical field around the wires, the ions react as if there were an entire sail there instead of just a thin wire outline.

And this is not only elegant and simple and damn brilliant—it is lovely.

A view of space, black and starry, with golden gusts of solar wind in the lower and left side of frame. A tiny spacecraft sits at the center of a starburst of glowing green electric wires, with arrows indicating the direction of ion movement and the pressure of the electron gun.

So beautiful! So poetic an idea! Sailing with invisible sails, on the light from a star, through the vastness of space …