So far, everyone who has ever traveled to space has done so in rocket ships, flying from the Earth’s surface on tails of fire and smoke. Space travelers are buffeted by high G forces. Several astronauts and cosmonauts have died, sometimes when their rockets have blown up. However, in the future, perhaps sooner than anyone thinks, this may no longer be the case. Traveling to space may be no more stressful than riding an elevator. It will certainly be a lot cheaper.

What is a Space Elevator?

A space elevator consists of a physical connection between the surface of a planet, preferably at the equator, to a point in geostationary orbit, which for the Earth is 35,786 kilometers high. The connection is like a train or a bridge, moving people, material, and power between a planet’s surface and space.

A space elevator has remarkable advantages in reliability and cost over using rockets to send people and material to space. Once the space elevator is built, the cost of travel to low Earth orbit would be several orders of magnitude smaller than using conventional rockets. The space elevator can also be used constantly, 24/7 if need be, and will be far safer to use than rockets.

The History of the Space Elevator

The idea of a bridge to the heavens is as old as the story of the Tower of Babel. In modern times, the idea of a space elevator was developed by Jerome Pearson in the early 1970s. Arthur C. Clarke consulted with Pearson and developed the idea of the space elevator in his novel, The Fountains of Paradise, which depicted the building of a space elevator anchored on the island of Sri Lanka, where Clarke makes his home.

More recently, NASA and private groups like the Life Port Group have studied the feasibility of building space elevators in order to greatly reduce the cost of accessing low Earth orbit and thus the Solar System beyond.

The Problems with Space Elevators

There are several problems facing those who might build a space elevator.

Where to Anchor a Space Elevator?

First, one has to find a place near or at the equator that is both geologically and politically stable. There are very few if any such places on the land. One solution may be to anchor the space elevator on an offshore platform, in the middle of the ocean. Weather is generally calm at the equator and such a station could be made accessible by ship or aircraft.

What Material to Build a Space Elevator From?

When the space elevator was first proposed over thirty years ago, no material then in existence was strong enough to withstand the tensions which would be required for a structure stretching from the Earth to geostationary orbit. Recently, a material called carbon nanotube has been developed that might fill the bill. Discovered in 1991, carbon nanotubes have a tensile strength that is over fifty times that of steel but of much lighter weight. In certain configurations it can either conduct or insulate electricity. It is many times thinner than a human hair. It is being considered for a wide variety of applications besides as a building material for space elevators. So far it has not been produced in quantity, but researchers are confident that problem can be solved in the near future.

What about meteors and other hazards?

One threat to a space elevator would be orbiting space debris such meteors or space junk. A space elevator can be designed to withstand micrometeor strikes that have occasionally pitted space craft such as the shuttle. For larger hazards, the space elevator will have to be designed to avoid them by moving the anchor platform and thus the elevator.

Of course a space elevator would be a prime target for a terrorist attack. Measures would have to be taken, including setting up no fly and no sail zones around the anchor platform, which would be in a remote location, and otherwise defending the elevator.

How Much Will it Cost?

Most researchers think that the first space elevator could be built at a cost of ten to fifteen billion dollars. Initially, it would cost a hundred dollars a pound to send something into space on a space elevator, but sharply decreasing as capacity and volume are added.

How Would a Space Elevator be Built?

A station would be deployed in geostationary orbit above the anchor platform. The nano carbontube ribbon would be produced at the station and slowly spooled out and lowered until it can be anchored at the anchor platform. The ribbon is thereafter kept taunt by the rotation of the Earth and a counterweight extended from the geostationary platform. The ribbon would be three feet wide and thinner than a sheet of paper.

How Would a Space Elevator Work?

Cars carrying people and material will climb and descend the carbon nanotube ribbon powered by electricity. They can go upwards to a hundred and twenty miles an hour, but without the sudden accelerations, vibrations, and G forces experienced on a rocket ship. Thus, fragile and large payloads can be carried. Once arriving at the geo stationary station, payloads can be released either into Earth orbit or into Earth escape trajectories to the Moon or to other destinations in the solar system.

The capacity of a space elevator can be augmented by adding carbon nanotube ribbons or by building new space elevators. In theory, there is no limit to the lift capacity that can be achieved with space elevators.

When Will Space Elevators be Built?

Arthur C. Clarke used to suggest that space elevators would be built about ten to fifteen years after people stopped making fun of them. With the development of carbon nanotubes and with renewed interest in space travel and space tourism, the time in which space elevators was a subject of fun has passed. If Clarke is right, therefore, we may see the first space elevators built some time in the later part of the next decade. The only question is, will the space elevator be built by a government, like the Apollo program or the shuttle, or by private industry. The best guess, if good policies are followed, is that the space elevator will be built by private industry, but with heavy government incentives and subsidies. That’s how the transcontinental railroad, which opened the American West, was built in the 1860s. It would be a wonderful historical irony if a “railroad” to the heavens, which would open up the high frontier of space, could be built using the space model.

External Links:

• Space Elevator Directory -