It sounds like something out of a science fiction novel or big budget movie: an elevator system that could bring goods and people into space. Instead of using rockets, a space elevator could move items up and down a strong cable line, with one end anchored to Earth and the other attached by a counterweight in space.
The only hiccup in this plan is the material needed to create the cable that would link space and earth. Sean Sun, professor in the department of mechanical engineering at Johns Hopkins Whiting School of Engineering, says, “It’s mathematically possible to use steel. But the design parameters would require so much steel that there’s not enough material in the entire universe.”
Currently, there is no material in existence that could withstand the tension caused by the pull of the counterweight, in addition to the force of the earth rotating, and the gravitational weight of the cable itself. To tackle this problem, Sun and graduate student Dan Popescu, have attempted to try bioengineering for a solution.
Many engineering structures function a fraction of the strength of the material or how far they can be manipulated without breaking. Biological structures usually operate near their maximum capacity, breaking and rebuilding consistently.
Due to this, Sun and Popescu believe that space elevators may not require such a strong cable if the cable is allowed to renew itself. This could be accomplished by creating a cable under continuous repair and service by autonomous robots. Instead of waiting for a break to occur, the autonomous robots will monitor the cable, so it remains viable.
There are ways to test this theory on Earth by using it to create other large structures like suspension bridges with weak but dynamic materials. Sun says, “If these pan out and prove to be economically feasible, a space elevator would be a natural next step.”
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