A space elevator would consist of a powerful cable, or tether, anchored on one end to the Earth and on the other to a counterweight in geosynchronous orbit with Earth.
A space elevator could easily get people and materials into space at a fraction of the energy and cost a rocket launch requires. Instead of burning expensive fuel to launch heavy objects off of Earth's surface, the elevator could convey them up the tether past lower Earth orbit and into space. It's not like people aren't working on it. The International Space Elevator Consortium (yes, it's a thing) will focus on tether climbing technologies at its annual conference this August in Seattle.
Engineers have yet to discover a method for creating a material that would be both strong enough and flexible enough to serve as the cable. It is currently possible to make nanomaterials that are up to a hundred times stronger than the strongest steel at a fraction of the weight. The problem is, once you try to build at a scale bigger than a few microns, the nanomaterials’ strength and stiffness start to decrease.
