Re:Ask HN: Making a low cost interplanetary "weather balloon"?
by carlosn on Friday March 22, 2013 @10:31PM
(#5427023)
I didn't mean small scale as in not reaching orbit with it, but as having a small payload.
I thought the weight of the elevator and its maximum payload with available materials were what keeps it from being built today.
A space elevator must stretch to at least geosynchronous altitude which is 35,800 km. Low earth orbit of 300 km sounds like 1% the effort, but does not help. The top of a 300 km structure on the equator would move at only 0.25 km/sec, nowhere near the 4 km/sec needed for orbit. (It could help if you built a launcher or railgun on top of it, outside the atmosphere, to skip air friction, but it can't literally elevate you into orbit.)