UTIAS Professor and Director Chris Damaren Speaks to U ofT Magazine About Solar Sails

Solar sails could propel ships to other planets – and even stars – with much less fuel…

Humans have long dreamed of going to the stars – but exactly how we’d get there has always been an open question. Once you’ve achieved a high speed, you can just coast along (thank you, Newton’s first law of motion) – but to get your speed up in the first place, you need some sort of propulsion system.

Today, we use chemical-burning rockets – but the fuel is heavy, which means launching a fuel-laden craft and accelerating it to an adequate speed requires even more fuel, and so on. The bottom line is that it’s costly and ineffective.

But there might be an easier way. What if we could rig up a “solar sail” that could use sunlight (or starlight) to propel a spacecraft, just as the wind propels a sailing ship? Jules Verne speculated about such technology in his 1865 novel, From the Earth to the Moon.

We’re now just beginning to use solar sails in real life, as scientists recognize the advantages that they offer, in some situations, over traditional chemical-powered rockets.

“The idea is that we’re using pressure from light photons as a means of propulsion,” says Chris Damaren, director of U of T’s Institute for Aerospace Studies. Damaren has been studying the feasibility of solar sail technology – using extremely thin materials that can intercept light from the sun, pushing a spacecraft just as the wind pushes on a ship’s sail. The analogy doesn’t end there: you can even steer a solar-sail-equipped spacecraft in just the same way that one steers a ship, by carefully adjusting the orientation of the sail.

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