Space Elevators
By Glen Hiemstra, 2000
A Tethered Space Elevator (TSE) is an idea proposed in 1979 by Arthur C. Clark, author of 2001. While still a wildcard, the notion of a Tethered Space Elevator is now closer than ever to becoming a reality. Meant to act as a reusable means of civilian travel into space, riding a TSE may be as common as airplane travel in as little as 35 years.
Since Clark’s brainstorm, many different designs of space elevators have been suggested. The most common design includes anchoring a tether in geostationary orbit, either to a Space Hotel or an asteroid, at a distance of approximately 22,000 miles from the Earth’s surface. The cable would then be linked to a launch station at a certain point on the equator. Anything in geostationary orbit revolves in conjunction with the earth’s rotation, thus the tether would remain over the same spot continuously. Along this tether a Reusable Launch Vehicle (RLV) traveling up and down the tether with the use of electric power, would be used to transfer civilians and freight to and from space.
Along with the tether extending from geostationary orbit to earth, another tether would extend beyond the space anchor to act as a counter weight and hold the space elevator stable. The upward tether could be used to release payloads into higher trajectories, boosting satellites or spacecraft into other orbits or to the Moon. The entire system is considered the most logical way to make space tourism possible.
However, the possibility of space elevators becoming common rests on the advancement of several developing technologies. Nanotechnology, through which the ultra-strong fibers necessary to make a material strong enough to hold itself up, as well as a RLV and all other equipment, would have to become commercially viable. The nanotube, created through the manipulation of carbon molecules, produces a material 60-100 times stronger than steel. The ability to mass-produce this material is expected to be developed in the next 15 years. Tether technology is also being advanced, to maximize the control of such long structures. Tall tower technology, which currently allows towers to be built nearly 2/3 of a kilometer tall, already has the capability of creating structures many times taller. Technologies needed to support the construction of the space elevator, including the transportation of utilities and materials outside of the earth’s atmosphere also need to be further advanced.
Safety and price for consumers are two prominent concerns about the actual viability of space elevators. The material produced through nanotechnology and then constructed into a multi-tethered design must enable the space elevator to survive micro-meteor impacts. Different methods of traffic control would also need to be utilized, along with eliminating the practice of dumping space junk in orbits near the space elevators to maintain optimum safety. While space elevators will initially cater to a small percentage of society due to their cost, as technology continues to advance and production increases, space elevators are expected to available for use by the majority of the population.
Space Elevators, if developed, will change space travel as we know it today. They have the capability of improving satellite launch, Space Station supply and crew exchange, or in-orbit construction. Space elevators may drastically change civilians’ relationship with space, and the way we live our lives on Earth.
Glen Hiemstra is a futurist speaker, author, consultant, blogger, internet video host and Founder of Futurist.com. To arrange for a speech contact Futurist.com.
Additional Resources
Discover Magazine, July 2004, cover story on the Space Elevator.
AmericanAntigravity, a good compilation of links to Space Elevator news.
LiftPort, a company dedicated to bringing a space elevator to reality.
Space Elevator Conference
