Science fiction doesn't always remain fictional. In 1863, for example, French author Jules Verne wrote an amazing book titled "Paris in the 20th Century." He wrote of glass and steel skyscrapers, calculators, fax machines, and a global communications network.

Even more remarkably, two years later he wrote his international best-seller, "From the Earth to the Moon." It was a huge success, but at the time, readers naturally had no idea that just 100 years later such an expedition actually would take place.

Now, NASA is working on turning another science fiction concept into reality. This one appeared 23 years ago in Arthur C. Clarke's book "The Fountains of Paradise." It's called the space elevator.

Original idea

The concept was first described in 1895 by Russian author K.E. Tsiolkovsky in his "Speculations about Earth and Sky and on Vesta." The first scientific journal account appeared in space science publication "Acta Astronautica" in 1975, authored by Jerome Pearson, who was working for NASA during the Apollo program.

"I was listening to Arthur Clarke giving testimony to Congress," Pearson said. "He was talking about geostationary satellites, which are used for communications around the world. And he described them as being perched above imaginary towers 22,000 miles above the equator."

Pearson, who now heads Star Technology, a South Carolina firm that conducts research and development for the Air Force, said he thought to himself, "Why not make a real tower? Why not drop a line down to the ground and actually connect one of those geostationary satellites to the ground?" Then, he imagined, an elevator or ladder could be made to go into space using electrical power rather than rockets.



NASA gets serious

NASA began considering the concept in June 1999 at the Advanced Space Infrastructure Workshop on "Geostationary Orbiting Tether 'Space Elevator' Concepts" held at the Marshall Space Flight Center in Huntsville, Alabama.

It brought together several dozen experts from NASA and private industry. A follow-up two-day workshop was conducted in Atlanta in late January.

In theory, the space elevator consists of a thin cable placed by the Space Shuttle into low Earth orbit (200 to 300 miles above Earth), and then raised to a stationary, geosynchronous orbit about 22,000 miles up.

The cable is then lowered down to the Earth's surface and anchored to a mobile ocean-going platform in the Pacific Ocean along the equator, several thousand miles off the coast of Ecuador -- an area chosen for its lack of hurricanes and ship traffic.

The cable is as thin as paper, but not as fragile. In fact, it has the same strength as diamonds, and consists of the same base element: carbon nanotubes.

Such a nanotube is "essentially a perfect tube of carbon, and they are 30 times stronger than Kevlar or steel and very light," said Brad Edwards, a physicist at Eureka Scientific who conducted a six-month study of the space elevator concept for the NASA Institute for Advanced Concepts program.

"We use those in a composite to make a long ribbon," Edwards said. "And the ribbon would be about 100,000 kilometers long."

The climbers

Once the initial small section of cable is secure, mechanical devices called "climbers" then move up and down the cable on rubber rollers. A laser on the anchor platform focuses beams at solar panels attached to the bottom of the climbers to provide power to their motors.

When the cable is complete, it will be capable of supporting payloads of 20 tons, more than the Space Shuttle can carry -- and for a fraction of the cost.

It may sound fantastic, but NASA already has put together several working groups to study the concept. David Smitherman of the NASA Advanced Projects Office coordinated the meetings.

"The consensus was, given proper technology development, there were basically no showstoppers that we could see of any major sort. It appears that over time, there is a reasonable way to solve all of the problems that we identified in the workshop about space elevators, and we believe they will eventually be possible to build," Smitherman said.

Above-Earth orbit

Once the space elevator is completed in stationary Earth orbit, about 22,000 miles up, scientists anticipate it could be used like a virtual slingshot to accelerate to other space locations.

Edwards said he looks forward to reaching other planets, such as Mars.



Of course, while all this may be technically possible, it doesn't mean NASA has the money to pay for it. The price tag for the initial Earth-based space elevator is estimated to be $40 billion.

That's where private industry comes in, because companies could benefit from space tourism launches, as well as from commercial satellites and scientific experiments.

"The cost of getting into space would drop by a factor of about 100 immediately," Edwards said. "In the long run, it could drop by a factor of about 10,000."

"Eventually it may not be much more expensive to go into space than it is to fly to Europe or Asia or something like that from the United States," he added. "It would also increase our capacity. We could launch much more into space, much larger things. We could launch space stations, assembled."

Smitherman said the project represents an opportunity from a collaborative as well as business perspective.

"This type of project is, in my view, one of those things that would be an international effort among governments and corporations," he said. "It's the kind of thing that has a lot of potential from a business standpoint."

Potential snags?

Along with the issue of cost, however, there are other potential roadblocks.

Robert Frisbee of NASA's Jet Propulsion Laboratory's Advanced Space Propulsion program anticipates risks such as terrorists targeting the elevator, as well as space debris -- either man-made or natural particles like meteorites -- hitting the cable.

Pearson, author of the 1975 journal article, said he isn't worried about meteorites, saying they are generally too small to cause any major damage to the cable's 10-foot diameter.

"The only problem we would have would be potential collisions with space debris and spent satellites, and so forth," Pearson said. "And what we would have to do is clean up low Earth orbit to get rid of those things."

Edwards admits the elevator could be a terrorist target. But, he said, "It's away from everything. There are few, if any, airline routes through there. And a few well-deployed ships would be able to protect the station, the anchor station, and the cable."

Although much of the technology already exists, or is in advanced stages of development, the space elevator's primary component is still far from perfected, and is the main impediment to moving ahead on the concept.

Edwards says he believes the timetable depends on the carbon nanotubes and the epoxy composite material that will hold it together.

"That's essentially the last raw technology that we need before we can do this. When that's done, if a concerted effort is put together, we could have the first operational space elevator 10 years after that," Edwards said.

Pearson said once the carbon nanotubes are acquired, "I don't see why we couldn't build one in the next 30 or 40 years."

JPL's Frisbee said, "There are several competitors to a space elevator, such as using electromagnetic catapults to fire things out of electric cannons. But as a way of getting material from the ground into orbit, it's really hard to beat the space elevator, in terms of cost, once the system is in place."

After Clarke wrote "The Fountains of Paradise," which included the space elevator concept, he was asked when such devices might actually come into use. His response: "Probably about 50 years after everyone quits laughing."

For more information on this topic, log on to:

NASA Institute for Advanced Concepts: The Space Elevator
By Bradley Carl Edwards

Space Elevator -- Technology Development Needs (April 5, 2001)
Compiled by David Smitherman

Space Elevators: An Advanced Earth-Space Infrastructure for the New Millennium (August 2000)

Acknowledgement: Our thanks to the San Francisco Hyatt Regency Hotel for the use of their atrium elevator during the shooting of video for this story.