Previous post:

Next post:

Solar Sails – Science fiction made fact

January 1, 2004

in All Articles,Astronomy,Solar power

The description of “solar sail” spaceships smells like science fiction, but taste it: It’s real.

Think of a kite. It’s held in the air by a rigid, lightweight frame, kept in the air by the force of the wind. A solar sail spacecraft works much the same way, only instead of wind, the sail is pushed by sunlight. You heard me: Sunlight. When we lay on the beach, the sun bombards us with photons – subatomic uncharged, zero-mass particles. A solar spacecraft’s sail catches photons like a kite catches wind. From this tiny but constant pressure, the spaceship moves. The propulsion requires no fuel.

The idea is fascinating in a techie geek sort of way, and indeed has appeared in many science fiction novels. As science fiction sometimes predicts the future, the ideas and stories from so many years ago are a reality. And it’s not just a cool idea. Solar sails benefit us.

“The whole purpose is not to have a gee-whiz tech we can fly in space, but to develop something to achieve actual strategic goals.”

So says Neil Murphy, and he certainly knows what he’s talking about. Murphy is the Supervisor of the Space and Astrophysical Plasmas Group at NASA’s Jet Propulsion Laboratory. You may have heard of the JPL’s work: They’re the ones responsible for travel to and robotic exploration of our next door neighbor, the planet Mars. The two Mars rover robots, “Spirit” and “Opportunity”, have remotely gathered massive amounts of knowledge, without endangering any human life.

NASA mission “Heliostorm” exploits solar sails’ fuel independence and their excellent maneuverability. Solar storms often interrupt Earth’s critical communication satellites, shutting down radios, cellphones, and other wireless networks. It’s essential these systems have advance warning when storms occur. Lives are saved by preparation. Currently, we have about three hours of warning before storms knock out communications. A solar sail spacecraft, launching in about 10 years, will fly closer to the sun than any of our current orbiting detectors. It will double our warning time.

More missions are planned, gathering knowledge and helping us better understand our world, our solar system, the universe, and how they affect each other. This goes beyond NASA. Murphy says, “A little while ago, there was a call for commercial activities using solar sails. I got involved with a small group of people that believed they could build and fly a commercial solar sail spacecraft.”

Apart from commercial plans, or missions like Heliostorm, the investment and time spent on solar sails is easily justified. Why did early explorers leave their homelands to chart the unknown? It’s nobler than simple wanderlust. From folks like Ferdinand Magellan, to curious and brave early humans, there’s always been an innate call to explore, learn, and understand. We must respond to that call and thrive, or knowledge and development will stagnate. Technologies solar sails are tools allowing us to answer that call. Let’s go explore.

Click to see solar sail pictures and the full interview with Neil Murphy.

Previous post:

Next post: