Space elevators – yes, literal elevators that will carry us into orbit – may not be as far from reality as we think, says one aerospace engineer and physics professor. According to his ideas, such a crazy concept could be realistic relatively soon – or, in his wise words: “We’ll know we are close when Elon Musk starts taking credit for it.”
So, what exactly is a space elevator? Well, humans are headed to Mars by 2040, if all goes well, and one of the largest issues with having a permanent extra-terrestrial colony is the logistics. Getting cargo and people up to space is a laborious, expensive task, as we are quite literally strapping them to high explosives and hoping it goes where we want it to.
A much better way, some believe, could be to put a really, really long string from the Earth’s surface all the way to orbit, and pass a pod up and down the cable. It would save on fuel, reduce emissions, reduce overall costs, and be far less dangerous than rockets. As you can imagine, though, space elevators do not come without significant challenges.
For one, how would the rope stay taught? How could we ensure that nothing comes along and destroys the cable, like terrible weather or astray space junk? How would you even build such a thing?
Stephen Cohen, a long-time space elevator enthusiast, believes he has all the answers in a recent opinion piece for Scientific American. Having studied the realistic implementation of a system and even published a master's thesis titled “The Dynamics of a Space Elevator”, Cohen believes it could actually be possible to take an elevator to the stars.
Here’s Cohen’s plan: a satellite orbits Earth in geosynchronous orbit at around 36,000 kilometers (22,370 miles) above the surface, untethered like all other satellites. The satellite drops a cable (a very, very long one) while using fuel to accelerate away from the Earth further into space. Using “gravitational and centrifugal effects”, the cable remains taut as it is fastened to the ground. Congratulations, you now have a space elevator.
Unfortunately, modern tech doesn’t quite cover it. The cable needs a specific strength of around 50 times that of steel, which Cohen has decided to ignore and leave to the material boffins while he sorts out the rest of it.
According to Cohen, we're likely around 10 years away from the material being made and we probably won’t be elevating up to space before 2040, when we shall supposedly be striding on Mars. However, it may not be too long afterward, Cohen says, which is a wild thought.
Most scientists remain unconvinced – space elevators have been spoken about for years and yet we are still bound by our mortal earthly coil with no end in sight. But, who knows, maybe the days of strapping ourselves to rockets could soon be over; we can only imagine the astronauts would welcome the day.