Wednesday, October 09, 2013

[qcgwzpcd] Sideways space elevator

If the vast majority of the difficulty of getting to orbit, at least low-earth orbit, is the horizontal speed and not vertical height, then that suggests a device different from a space elevator.  Achieve the horizontal speed on the ground in a long evacuated tube, then add a vertical component of velocity with rockets.  You save by not having to carry (nor lift) fuel for horizontal power.  Instead, horizontal acceleration could be done by ground-based methods, for example, linear motor.

Air resistance after exiting the tube will be a very big problem.  Maybe extend the tube up the side of a very tall mountain.

This has already been thought of: rail gun.

Inspired by http://what-if.xkcd.com/58/

The tremendous horizontal speeds necessary call into question the usefulness of a space elevator, and also make me wonder whether a space fountain would even work.

No comments :