Come sail awayPart One
By Rod Myers, Naturalist
We have lingered long enough on the shores of the cosmic ocean. We are ready at last to set sail for the stars. Carl Sagan
The nearest star, Proxima Centauri, is 25 trillion miles away, or roughly a distance of 4.3 light years. Thats the distance light travels in 4.3 years at 186,000 miles per second. Our fastest-traveling spacecraft, which is currently heading deeper into space, is Voyager I. Its speed is 38,400 miles per hour. To reach our closest star neighbors in a reasonable amount of time, we would have to approach traveling at the speed of light at least by one-third. In other words, youd have to make a craft that could travel 8,000 times faster than Voyager I just to get to Proxima Centauri in 12 years.
Many in the space field believe it will be centuries before well be able to travel to the closest stars. Its obvious we wont get there with a self-contained propellent rocket. The larger amount of propellent needed to reach one-third the speed of light and then maintain that speed would bog the rocket down with weight. Whats needed is a power source not contained on or in the rocket.
For decades now, research scientists think they have a reliable power source. For interstellar space flight, the source they are touting is the sun. The sun expels atomic particles into space in a constant solar push; some of the particles approach or match light speed. A device used to catch and be pushed by the enormously powerful solar wind would be none other than a solar sail. Yes, a sail, an object shaped like a sail, a huge one thats super thin, just a micron thick. A square meter of sail would catch a kilowatt of energy; a square kilometer would catch a gigawatt of energy. There is one catch, though; one must get into nearby space before the suns full power is felt. But a vessel launched from Earth could reach deeper space with the aid of microwaves pushing the sail. Until our technology is vastly improved, unmanned probes would be the most feasible at first. Their weight would range from 20 grams to 100 tons. Explorational manned vehicles would have masses upwards of 100,000 tons.
The solar sails should have been built 20 years ago, but NASA being conservative and not knowing where the next government dollar was coming from, didnt have time to waste on what they thought was pie-in-the-sky technology. Thank goodness for private research and the non-profit Planetary Society, who recently helped complete construction of Cosmos I, the first solar sail.
If solar sails become useable as predicted, their first and most logical missions will not surpass our solar system. From Mercury to Pluto, our own solar system has a lot to offer. Trips that would take many years to make could be done with solar sails in a much shorter time. Scientists plan to launch Cosmos I into space sometime this year, with help of several countries assisting and the 100,000 member-strong Planetary Society. Who would have ever thought that the future of space flight may depend on sails? Ask a man of the sea; he wouldnt laugh; as all sailors know, the first serious sea travel involved sails dependent on the sun. The sun produces the wind because it is the mother of all weather. But would you believe there can be no weather on Earth without weather in space?
Rod Myers is a local resident with an interest in the environment and disability issues. He has an associates degree in science and a bachelors in fine arts. Rod is a member of the Audubon Society, the Wild Ones Natural Landscapers and Rockford Amateur Astronomers, Inc.