Astrophysicists Say One Space Elevator Concept Is Possible With Today's Technology
Getting spacecraft into orbit is incredibly costly and difficult, and so scientists keep returning to the idea of a space elevator that can lift people and equipment out of Earth's atmosphere more easily. Now researchers have come up with a twist on the concept that - in theory at least - is doable with today's technology.
Rather than building a space elevator up from Earth, build a 'spaceline' down from the Moon, say astrophysicists Zephyr Penoyre from the University of Cambridge in the UK, and Emily Sandford from Columbia University in New York.
Based on their calculations, the researchers say such a construction is technically and economically feasible with the tools and materials we have today – something that can't be said for the space elevator concept.
The benefit of a spaceline over a space elevator is that it would orbit Earth just once a month – because it would be attached to the Moon, not Earth – and that means less of a strain coming from centrifugal forces.
It wouldn't actually touch our planet, but dangle down into geostationary orbit – some 42,164 kilometres (26,199 miles) above the surface – ready to transport whatever was needed up into the further regions of space.
"By extending a line, anchored on the moon, to deep within Earth's gravity well, we can construct a stable, traversable cable allowing free movement from the vicinity of Earth to the Moon's surface," write Penoyre and Sandford in their paper.
"It would reduce the fuel needed to reach the surface of the moon to a third of the current value."
Crucially, super-strong materials that we already have, including the Zylon carbon polymer, would work in this scenario.
By hitting what's known as the Lagrange point – where the gravitational forces of the Earth and Moon would come close to balancing each other out – the researchers think enough stability for operations can be achieved. ...
