It is amazing how many things that were science fiction just a few short years ago are now a reality!! I also wonder if the sci-fi writers were really smart and could figure out what would lie ahead in the future, or if today's scientists and technicians were avid reader of science fiction and had the dream of making it come true, or if the development of technology just took that route on its own. But to me, it is ironic how many things from some of the old sci-fi TV shows and movies have come to be a reality. I have told you about a lot of them in the past, but today I would like to talk about the ion engines that powered space craft in the old movies, like Star Wars, Battle Star Galactica, and Star Trek. Am I bringing back any memories? This "ion engine" was fiction but today it is a reality. In fact, the Dawn space craft is powered by one. Dawn is on its way to visit a couple of asteroids, Vesta first and then Ceres. But first, it will swing past mars for a gravitational boost. It will travel 1.7 billion miles before reaching Vesta and 900 million more miles to reach Ceres.
This trip would be near impossible if using conventional fuel where a flammable fuel is combined with oxygen and burned and the exhaust pushes a craft through space. A space craft with conventional rockets would have to be enormous just to carry the fuel needed, and thus, a lot more expensive and heavier to launch. The ion engine solved this problem, although it was launched aboard a conventional rocket and then turned loose to go on its own. It carries 937 pounds of Xenon gas on board as its fuel. If it would have been powered by a conventional rocket, it would have needed to carry two and a half tons of rocket fuel. Dawn's ion engine uses solar panels to obtain the energy to create electric fields that accelerate a beam of positive Xenon gas ions that shoot out the rear of the craft at 90,000 mph. It is 10 times more efficient than regular fueled rocket engines. It will take a long time to reach both of the largest known asteroids, but Dawn is up to the task with its Sci-Fi ion engines working just fine. BTW, it was launched in September of 2007 and reached Vesta on July 2011 and sent back wonderful pictures. It should reach Ceres by February 2015. Aren't ion engines wonderful? Now you all have a great day now, you hear?