Lovin' an Elevator... To Space
The concept of the Space Elevator is an old one, popularized by Clarke and trail blazed by Russian scientists generations ago. The Space Elevator has always seemed a thing of fiction. The subject of wishful thinking techno-utopian day dreams. But the technology has caught up with us. Real working Space Elevators are now within reach. The question is whether or not we will build them. The physics behind Space Elevators is very simple. Basically it is a ribbon, with one end anchored firmly on earth, and the other end attached to a heavy weight 100,000 kilometers (62,000 miles) from earth. The ribbon is kept aloft by the earths own rotation. No astounding technical feats required, simple physics does all the heavy lifting for us. To Illustrate this principle, think of a ball at the end of long string. If you swing the string around fast enough (earths rotation), the ball's inertia keeps the string string extended, and it will continue to orbit, so long as you continue swing the string.
To leave earths atmosphere once the ribbon is in place, vehicles would only have to "climb" the cable. No more loud, messy, expensive rockets. Cable cars would shoot up and down the elevator carrying tons of cargo and even people, like bullet trains with tracks leading to the stars. The advantage we would gain over rocket propelled flight is, in a word, astronomical. Rockets must also lift the weight of their fuel to move into space. Thus getting one kilogram of mass into orbit costs around $20,000. 1 kilogram of mass put into orbit using the Space Elevator would cost around $200. About twice the cost of shipping the same mass from Detroit to Tokyo, or the cost next day air from New York to LA. Orders of magnitude less expensive than using our fleet of aging space shuttles.
Proponents estimate that the actual construction costs of the Space Elevator would range from 6 to 8 Billion dollars. To put that in perspective, that's about half of NASA's budget for one year, or half of what we spent bailing out the airlines in 2001, or one month of daily operations in Iraq. Once the first elevator was operational, we could use it to reduce the cost of a second one dramatically. Very shortly, we could have a host of elevators, eventually dropping orbital costs down to as little as ten dollars a kilogram. At that point the economics of space would explode. Energy companies could build gigantic solar arrays to beam non stop renewable power to the earth for pennies, mining operations on the moon, space hotels, solar system cruises, personal satellites, and a myriad of things we haven't yet imagined.
Early elevator development has been very successful. LiftPort, one of the leading Space Elevator companies, recently tested out their prototype climbing vehicles on a tether connected to a newly designed high altitude platform that was over a mile up! Both skeptics and proponents agree that the last real technical hurdle is the ribbon itself. We need something with a strength stronger than that of steel, that weighs less than a feather, and can be made in a sheet that's only feet wide, and more than 62 thousand miles long. The only possible material that fits that bill are carbon nanotubes. Tiny structures of pure carbon, woven together into super light super strong strands. Up until a few years ago ten centimeters was about the limit for a length of nanotubes, and making ribbons was a very long and expensive process. But things are changing. As early as 2004 they were pulling hundred meter long nanotube threads from the furnaces at Cambridge. And in the fall of last year, researches at the University of Texas developed a process that makes sheets and ribbons of nanotubes at a rate of seven meters per minute! The resulting material is stronger than steel or Kevlar, one step away from what we need to hoist the Space Elevator up by it's bootstraps. Watch the remarkable video, and see the future of space flight in it's infancy.
If I had to give you one name to watch for in the coming days of Space Elevators, it would be former Los Alamos researcher Dr. Bradley Edwards. He's on the Board of Directors (along with Liftport's Michael Laine) at Spaceward, the group behind Elevator 2010. So called, because they plan to have all of the technical details solved by that year, and a working Space Elevator built by 2020. His particular vision of the Space Elevator is the best developed, and he is said to have some very large investors waiting in the wings once all of the technology is where it should be. Check out his Spectrum article for more on the elevator, and some inspiring images. Dr. Edwards might turn out be the Von Braun of this new era of space flight. One thing is for sure, I'm getting in on the ground floor. GOING UP!
"Don't tell me that man doesn't belong out there. Man belongs wherever he wants to go--and he'll do plenty well when he gets there." - Wernher Von Braun