Sunday, July 5, 2009

Space Elevator on the Moon

While camping I was discussing the idea of a space Elevator on the Moon. Justus quite rationally pointed out that unlike the earth there is no way to put something in geosynchronous orbit around the moon. This is because it is tidally locked with the earth and doesn't spin. This means there is nowhere to put a space elevator on the moon. Now, i was sure i had heard plans about putting a space elevator on the moon, so it took me a while to believe him, but the more I thought about it the more obvious it was he was correct.

So i went to wikipedia's page on a lunar space elevator. Sure enough, Justus was correct, it can't be in Geosynchronous orbit. However I was right that it is feasible. It just has to have its center of mass at L1 or L2. At these points on either side of the moon the gravity from the Earth and moon, as well as centrifugal forces add up to zero. What makes this idea most exciting is that it could be made from Kevlar! Many existing materials are strong enough to build it.


Justus said...

So really all of our space effort (money) right now should go into establishing technology for a self-sufficient moonbase. That would set the stage for mining etc. on the moon and transport of raw materials to orbit and beyond using an elevator that does not depend on theoretical materials. Repeatedly sending heavily-laden rockets against earth's gravity is a terrible way to interact with space.

glmory said...

That would certainly be a big step up from whatever the heck NASA's plan is right now.

I suspect that we will go through two new space shuttles though before flight is cheap enough that we can build the moon base though. NASA really needs priority one to be building a better space shuttle. After that everything gets easy.