News for hackers. Stuff that matters.
Re:Ask HN: Making a low cost interplanetary "weather balloon"? by T-hawk on Friday March 22, 2013 @01:33PM (#5424314)
There's no such thing as a small scale space elevator. The difficulty in reaching orbit or elsewhere in the solar system is not altitude, but enough horizontal velocity to continually fall and miss the earth or reach escape velocity entirely.

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.)

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.