Tau.Neutrino said:
Space elevator
On the near side of the Moon, the strength-to-density required of the tether of a lunar space elevator exists in currently available materials. A lunar space elevator would be about 50,000 kilometers (31,000 mi) long. Since the Moon does not rotate fast enough, there is no effective lunar-stationary orbit, but the Lagrangian points could be used. The near side would extend through the Earth-Moon L1 point from an anchor point near the center of the visible part of Earth’s Moon.
On the far side of the Moon, a lunar space elevator would need to be very long—more than twice the length of an Earth elevator—but due to the low gravity of the Moon, could also be made of existing engineering materials.
Could you have a dual or triple powered space elevator ?
> Since the Moon does not rotate fast enough, there is no effective lunar-stationary orbit
Yep. That’s why a space elevator on the Moon is a bad thing.
Remember that the Russians safely brought back rocks by launching them from the Moon using an absolutely tiny rocket, just 1.5 metres long. Rocket from the Moon is good, but if the fuel needs to be manufactured on the Moon itself then a rail gun is the best for mass transport because, unlike the Earth, there’s no atmosphere on the Moon to rob the rail gun projectile of energy.
It was pointed out to me some time ago that the ideal place for a space elevator is Mars. That remains true. It has all the necessary components of spin, significant atmosphere (which rules out railgun), and low gravity.
> but the Lagrangian points could be used.
Aaaaaagh! No. You do know how far the Lagrangian points are from the Moon, right.
> Could you have a dual or triple powered space elevator ?
You’ll have to explain that in more detail, please.
This is a picture of the Luna 16 ascent stage rocket taking rocks from the Moon to Earth.
