by Jake Meyer
Space elevators are a simple idea that could make transporting passengers or cargo into space relatively easily and inexpensively as compared to our current method of space transport – igniting millions of pounds of fuel to blast a rocket out of our atmosphere. Most concepts for a space elevator involve a tether anchored to the earth, for example on a floating platform somewhere in the Earth’s oceans. The tether would stretch 100,000 kilometers or so from Earth, past the Earth’s atmosphere and into space where the tether would be attached to a large counterbalance. This counterbalance would orbit the Earth while the centrifugal forces from the earth’s rotation would keep a constant tension on the tether. Under a constant tension, the tether could be used as a rail for a lift or “climber” that could ascend the tether into space carrying with it a payload of cargo or passengers.
Besides making space transport inexpensive, space elevators could also solve our need for environmentally friendly energies. Space elevators could be used to install large solar power satellites in space that could provide us with inexpensive and continuous energy. These types of projects are not feasible with our current rocket technology.
There are several challenges to be overcome before a space elevator can be realized. One challenge is how to power a “climber” up the tether. In December 2008 at the Second International Conference on Space Elevator and Carbon Nanotube Tether Design in Luxembourg, Age-Raymond Riise of the European Space Agency demonstrated a possible solution by using a broomstick. By using mechanical vibrations on the tether, a climber could be made to climb the entire length of the tether. This solution may have challenges of its own, however, as the vibrations could make for a bumpy ride into space.
Another challenge creating a space elevator presents is finding a material that is strong enough to be used as a tether. Carbon nanotubes may be able to provide the strength-to-weight ratio that would be needed for a space elevator. But researchers may be deterred from working with carbon nanotubes for fear of patent infringement or may not be able to negotiate licenses from what might be multiple different patent holders. Patents are being granted on carbon nanotubes that are unduly broad and that are overlapping. Due to inappropriate patents, the development of an extraordinary application of carbon nanotubes, such as a space elevator, might be slowed or lost completely.