An Elevator to Space? Better Take the Stairs

Space — Elevator Cable

Some ideas just refuse to go absent: trickle-down economics, the bolo tie, couscous. Add to this the space elevator. If you are not acquainted with the space elevator, perhaps you've listened to it referred to by one of its other names: the bean stalk, the orbital tether, the nonsynchronous orbital skyhook. No? Well never ever mind, due to the fact as opposed to the bolo tie, it does not exist. And as opposed to the tie as well, it probably by no means will — not in this life span at least. But never inform Google that.

The space elevator has been again in the information lately since of tech-entire world buzz that Google X — the secret Skunk Performs exactly where the company that gave us excellent doodles, a great Web browser and so-so e-mail — has incorporated it on its list of what-if technologies it is trying to help produce. That is cool news, and it made for awesome quotes, with the New York Times referring dreamily to Google's "100 shoot-for-the-stars concepts" and the Irish Times predicting confidently that "the space elevator may effectively exchange rockets in 50 years." (See photos of the top 10 strangest items sent into space.)

Possibly, but here's an essential hint for aspiring futurists: "within fifty years" is nearly often geek-speak for "Like, um, never?" Here is why.

The space elevator is exactly what its title says it is: a long cable anchored at one stop to the ground and at the other finish high in space, protruding from the planet like a spoke in a rotating orange. Just attach an elevator auto, strike the up button, and you can climb easily into the sky. When you get to the orbital altitude you want, open the doorway (do not forget about your helmet!) and hop out.

The concept is basic — indeed, so simple that it was first proposed in 1895, when Russian rocket scientist Konstantin Tsiolkovsky, the thinker father of such afterwards greats as Robert Goddard and Sergei Korolyev, envisioned a large tower connected to a "celestial castle" that would let straightforward entry to the then unreachable cosmos. Tsiolkovsky's first mistake was recommending a rigid, fixed tower instead of a cable, since it would have to support its considerable excess weight from beneath as opposed to simply currently being decreased from above. But that was just the beginning of the construction problems. (See photos of Earth from space.)

In order for the castle, or orbital counterweight, to remain stationary relative to the rotating earth, it would have to be positioned 22,238 miles (35,790 km) in space — or about 10% of the length to the moon — in which the time it takes to total a single orbit matches the 24 hours it normally requires the Earth to switch. In lower Earth orbit, say 220 miles (355 km) up, where most human space travel normally requires location, a one circuit is accomplished in a considerably brisker ninety minutes.

O.K., so step one is building a cable that's 22,238 miles lengthy. Effortless ample to envision — now what's your construction material? Normal metals like titanium, steel and aluminum and acquainted synthetic fibers like Kevlar and fiberglass are either also hefty or too breakable or equally. The answer: carbon nanotubes. (Hint No. 2 for aspiring futurists: carbon nanotubes are the fallback substance for practically something fanciful that has not been invented but.)

Nanotubes are truly fairly nifty in principle — molecular strands of carbon molecules arranged in hexagonal configurations that are made up of much far more empty space than mass. This makes them unbelievably strong and unbelievably light, and they have presently been manufactured in strands with a duration-to-diameter ratio of 132 million to one. That implies they are extremely, extremely long relative to their girth, so a 22,000-mile (35,400 km) cable should be a snap, proper? Nicely, no. Remember, the girth we are conversing about is on the molecular scale ( via ).