Such an elevator would drastically lower the cost of sending materials into space, from $20,000 per kilogram to perhaps as low as $200. If that’s the case, the cost of building such an elevator would be recouped after having sent 1 million tons of cargo.

So what’s preventing the construction of these elevators? As of now, we don’t have material strong enough to serve as the tether. Some studies have said carbon nanotubes aren’t strong enough, and current hopes are pinned on diamond nanothreads. Estimates suggest that the material needed for a tether will be developed by 2030.

 

Construction could also be derailed if an alternative technology is developed that makes space elevators unnecessary. SpaceX and other companies are trying to create reusable rockets, which are also expected to lower costs. If they are successful, the space elevator may be permanently relegated to its current place in sci-fi.

 

This story first appeared on Futurism and is modified and republished here under the CC-by-NC license.