27 March 2006

Why Take a Rocket Ship?

March 14, 2006
Why Take a Rocket Ship?
By David R. Butcher

A working space elevator could reduce the cost of launching anything into space by roughly 98 percent and would increase the amount of cargo capacity for orbital trips. The theory is solid, the materials exist, and inventors and entrepreneurs continue tinkering.

Imagine the title transport device of Roald Dahl’s Charlie and the Great Glass Elevator (the follow-up to the more popular children’s book), becoming a reality. That is the lofty goal of NASA and a number of private companies.

Last October saw the first NASA-sponsored Space Elevator Games, which offered a $200,000 prize to the first team that could make a machine climb up a 164-foot tether, powered only by a mirror and a beam of light from a 10,000-watt bulb. Actually, none of the home-brewed contraptions on display could reach higher than 40 feet.

But dammit, government and private-sector spending is soaring. And indeed, the hottest idea in space enterprise is a tether to take us all the way from Earth to orbit.

Worldwide government spending on space is reaching $50 billion a year, a one-quarter-percent jump over 2000. NASA represents only $16 billion of that total, but during the next 20 years, the U.S. space agency is likely to sign contracts totaling as much as $400 billion to launch a human mission to Mars. Further, in 1998, private-sector spending on space applications began to exceed government spending, and that gap is widening. A critical mass of entrepreneurs have been backing space-related companies for years.

So why such importance on an elevator, something so seemingly banal we may actually ride one when shopping for clothes at the department store?

A working space elevator would reduce the cost of launching anything into space by roughly 98 percent. The $500 million it takes to launch the average satellite (insurance not included) would be history. In addition to cutting costs, the space elevator would increase the amount of cargo capacity for orbital trips; more than 90 percent of a space shuttle's weight is fuel, with cargo making up less than 5 percent. But no fuel is necessary on the elevator, because the car would be electric, with power cells energized by a ground-based laser beam. (Of course, like all things, there is a downside.)

The theory behind the elevator is quite manageable, as a recent Business 2.0 article points out. First proposed 111 years ago by a Russian scientist, the idea was popularized by Arthur C. Clarke in his 1978 novel, The Fountains of Paradise. It goes like this:

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