Solar Sail: Solar Powered Spacecraft in Its Infancy?

A very simplified definition of a solar sail is a device that gathers light from the sun and transfers that light energy into momentum or power--the power to propel an object by way of the reflection of pure light off the object. The technology of using nothing but light to actually generate propulsion or lift that is aerodynamic-like in behavior has been achieved. This technological advancement rests on the fact that photons (particles of light) create pressure when they bounce off objects. They can create enough pressure to literally move the object. This reflective "power" of photons is being studied in hope that rocket scientists can some day soon build solar powered spacecraft or solar sail spacecraft. This would be a truly amazing feat, one that would dwarf even the most powerful rockets that have been used in the past for space exploration.

The Steering Problem with Solar Sail

Engineers of solar sail realize that, in order to succeed with this technology, they will have to devise a spacecraft that is amazingly reflective to truly push the idea of solar sail out of theory and into practice. A tremendous amount of solar power will be necessary to actually rely on energy from the sun to shoot spacecraft into the "final frontier." They are experimenting with highly specialized material for this very purpose. There is, however, another problem--steering.

However much power is behind solar sail, a solar sail spacecraft must be able to be steered with great accuracy, particularly if it carries astronauts who want to make it back home to Earth. Most engineers working on the idea believe that the answer lies in delicately designing solar powered spacecraft with flawless precision so that they have perfect control over where and when light energy bounces off it.

The Not-So-Sunny Side of Solar Sail

Some astrophysicists believe that the sun, which is a star, might be "burning" out and eventually cease to shine. Would that be so many years into the future that engineers of today's technology need not preoccupy themselves with what to do about solar powered spacecraft in the event that the sun ceases to shine? Use of solar power to this magnitude would truly seem miraculous and like a testimony to what man is able to accomplish through technology. However, no matter how advanced solar sail becomes, it still relies on the sun which, if dying, man cannot save.

Astrophysicists are not the only ones who believe that the sun will not continue to "rise" over Earth; but, their beliefs are not based solely on traditional science. They are based on another book that has been proven scientifically accurate. "And I beheld when he had opened the sixth seal, and, lo, there was a great earthquake; and the sun became black as sackcloth of hair..." (KJV, Revelation 6:12). There will be no solar sail in those days.

Source:

Kate McAlpine
Lightfoil Soars on a Stream of Photons
NewScientist.com