Build a Space Elevator with Nanotechnology
Does the idea of an elevator from earth to other planets seem far-fetched? Perhaps to you it does, but not to nanotechnology scientists. In fact, today, they are working on building the cable that the elevator cars will run on.
The space elevator is a device that could provide an alternative way to put things in orbit. Just like the elevator in an office building, the space elevator could be used to transport both materials and people. As with conventional elevators, the space elevator will be fitted with a cable. However that cable will have to be stronger than any cable you’ve ever seen.
Roughly 90,000 kilometers long, the space elevator cable will be anchored at the top to an asteroid (called the counterweight) in orbit around the earth, and at the bottom by an anchor station, perhaps floating in the ocean (similar to an oil-drilling rig). Such a cable will probably be made from carbon nanotubes.
Researchers at the Macromolecular Materials Laboratory at Cambridge University have developed a method to make carbon nanotube fibers more cheaply by spinning them into a fiber as they come out of the vapor deposition reactor (a machine filled with hot carbon gas) where they are created.
The researchers have managed to produce samples several times stronger than steel and are working to increase the strength of the fibers, as well as making the quality of the fibers more consistent. They believe that the process could produce nanotube fibers inexpensively when scaled up to production volumes.
This and other methods to produce fibers and cables from nanotubes will certainly be used for other applications, such as bulletproof vests, before producing cables strong and long enough for the space elevator.
Solar cells would be placed on the space elevator cars. By shining lasers from the anchor or space station onto the solar cells, the system would receive the power required to drive a car up or down the cable. This energy system would reduce the weight that would have been taken up by storing fuel in the car, leaving more capacity for cargo.
Although there are some engineering challenges, perhaps the most intriguing of which is actually stringing this 90,000-kilometer cable between the anchor station in the ocean and the counterweight asteroid in orbit, steps are underway to address those challenges. For example, yearly competitions conducted by the Spaceward Foundation are providing a focus for energetic minds to demonstrate prototypes and earn some substantial cash prizes.
The competition focuses on the two main challenges of developing the space elevator: One is on developing a cable with the combination of high strength and light weight; the other challenge is to develop climbers powered by lasers on the ground that can climb the cable.
The folks at the Spaceward Foundation liken their space elevator competition to various other engineering competitions. They’ve drawn comparisons to a time when early aviators were trying to convince the public that there was a future for air travel. In those days, air shows entertained but also conveyed the message that air travel was a viable industry of the future.
In a similar way the Elevator competitions build enthusiasm for the space elevator’s future and generate great ideas. Prize money for the competition is provided by a program at NASA called Centennial Challenges.
A report by NASA’s Institute for Advanced Concepts gives a good introduction to the techniques necessary to construct the space elevator.
The Space Elevator Group has an FAQ page that provides answers to some key questions about the space elevator.