The idea of space exploration is nothing new. To people of my generation (gods! I sound like my grandmother!) it’s always been a given that someday people would be flying through space in huge metal cans discovering new planets and hopefully new civilizations. To boldly go…..
For most geeks, space exploration is a staple part of our intellectual diet.
When we think about space travel,we think jet propulsion, fuel cells, dilithium crystals, antimatter engines, etc… All of these are essentially chemical reactions that creates thrust and pushes the space craft where the crew wanted it to go.
But did you know that there’s an alternative to sitting on top of a volatile mix of reactants that could blow you to kingdom-come should something go wrong?
It’s called the solar sail. A thin sheet of essentially plastic which harnesses solar wind to push it through space.
Okay, I can see you scowling from here. Solar Wind? The sun doesn’t produce wind!
Well, technically that’s correct. The sun gives off waves of energy in the form of photons. Waves are a transfer of energy from one location to another. What a solar sail does is it harness the momentum generated by the photons in a wave of light to propel the ship it’s attached to through space. Because there is no friction and therefore nothing to slow it down, the very slight push from these light photons will be enough to generate the propulsion necessary to keep the ship from being affected by planets’ gravitational fields and to keep it moving at a constant acceleration until someone puts the brakes on.
At least, that’s the theory. No one’s been able to launch one of these things despite the concept being around since 1924, when Friedrich Zander first proposed the idea. It’s been fuel for science fiction stories for years, including Jack Vance, Gateway to Strangeness (1962), Arthur C. Clarke’s Sunjammer (1964), and most recently in Star Wars: Attack of the Clones (2002) and in James Cameron’s Avatar. But no one’s been able to get one of these things working.
Japan’s Aerospace Exploration Agency (JAXA), is ready to launch the IKAROS, the first fuel free space vehicle on May 18th.
The IKAROS is essentially a 46 foot wide kite, constructed of polymer sheets thinner than a human hair and equipped with solar cells that will generate the power needed for ground control to steer the ship where they want it to go. The power will also be used to turn the sails to catch as much radiation as they need to propel the craft forward. The whole kit and caboodle costs $16 million and JAXA has no guarantee that this will succeed.
I really hope they succeed. It certainly would return the romance to space travel.