What is Solar Sailing?

Solar sail propulsion is simple in concept. Light photons bounce onto a mirror-like aluminized Mylar sail. As each photon hits, its momentum is transmitted to the spacecraft.

Photons have no mass but lots of energy, so a solar sail space probe requires no onboard fuel. The force acts continuously, meaning a solar sail can eventually reach speeds five to ten times greater than any chemical rocket.

Russia, the U.S. and the European Space Agency all started solar sail missions and technology programs but cut them back when money got tight. Japan, we are happy to say, is now moving ahead to develop an innovative solar sail and solar-powered ion drive hybrid.

Yet solar sail propulsion remains largely neglected. That's why the Society has long championed efforts to prove its value. We partnered with Cosmos Studios on the far-sighted Cosmos 1 solar sail project. But technology has advanced enormously since then. We can do more in a fraction of the size, with a fraction of the weight and at a fraction of the cost. This has led us to re-think everything…and what we've arrived at is far more advanced, and ultimately far more valuable.

This technology also opens up many new possibilities for piggyback launching into Earth orbit, which is desperately needed since launch vehicles have been a hindrance preventing solar sail flight. We're considering several launch possibilities and will select the most reliable one that matches our schedule and final orbit choice best.