Imagine a cable extending from Earth’s surface right into space – an “elevator” for transporting cargo, supporting manned missions and even space tourism. This is the basic idea that is the space elevator, also called orbital tethers, space lifts and skyhooks. Although a common device in science fiction, the idea isn’t as infeasible as it might sound. Researchers are taking the idea seriously (see links and sources for more details).

However, it’s not simply a case of building a very tall skyscraper. It would get heavier with every floor you added, until it could no longer support the weight. Would the cable suffer the same problems? Yes, even a light rope would be heavy, simply because so much would be needed for such a distance. The way to eliminate this problem is keeping it taut from the space end.

Attaching the cable to a geosynchronous object may be the answer. If an object is in geosynchronous orbit, it takes a day to orbit the Earth, in keeping with its spin. In fact, this is how many satellites orbit Earth.

Finding suitable materials for use as a cable is difficult, but one possibility is to use carbon nanotubes, which have a high tensile strength. Although a space elevator would be costly to set up, it would result in more accessible space travel – cheaper and possibly safer. Getting into space has always been the most expensive part of space travel.

The safety issues do have to be given a lot of consideration, and there are many potential problems such as the impact of severe weather, the possibility of terrorism, and collisions in space. Such problems are best dealt with by developing preventative measures. For example, a space elevator would be installed in a “storm-free” area. It would also be monitored rigorously!

The topic of space elevators is one that’s difficult to keep short, but fear not, there are already some great resources out there. The LiftPort Group website have an excellent FAQ on the development of space elevators. Also, read Audacious & Outrageous: Space Elevators on NASA’s sites, an easy-to-read article with links for further reading.

Sources

The Space Elevator Comes Closer to Reality, Tech Wednesday (Space.com website), published: 27th March 2002, accessed: 4th January 2009, author: David, L.

Audacious & Outrageous, NASA Science News website, published: 7th September 2000, accessed: 4th January 2009, author: Price, S.