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Re: YASID: Moon in a very low orbit.

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Greg Goss <gossg@gossg.org> wrote in news:d5kn6uFijpuU1@mid.individual.net:

> Cryptoengineer <treifamily@gmail.com> wrote:
> 
>>Don Kuenz <garbage@crcomp.net> wrote in news:20150912a@crcomp.net:
>>'Orbital flight'? Or 'reaching orbital height'? There's a huge
>>difference in energy and guidance requirements. The latter is
>>much easier to do.
> 
> But what is "orbital height"?  I remember reading an SF short story
> about a guy wondering at the various holes and valleys on a planet he
> was exploring (Mars?) and realizing just in time that a super-dense
> moon was orbiting rather low.

'Orbital Height' is the lowest altitude at which something can be in
a stable, longlasting orbit. Around the Earth, and most planets, 
atmospheric drag is the limiting factor - the lowest Earth satellites
are about 100 miles up.

If there's no atmosphere, its high enough to clear the tallest 
mountain, though I suspect that close to the surface, irregularities
in gravity becomes a problem, and could perturb an otherwise good
orbit into one which intersects the surface.

pt

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Red Thunder, here we come! Joe Bernstein <joe@sfbooks.com> - 2015-09-11 21:01 -0700
  Re: Red Thunder, here we come! Don Kuenz <garbage@crcomp.net> - 2015-09-12 17:01 +0000
    Re: Red Thunder, here we come! Cryptoengineer <treifamily@gmail.com> - 2015-09-12 15:24 -0500
      Re: Red Thunder, here we come! Don Kuenz <garbage@crcomp.net> - 2015-09-12 22:31 +0000
        Re: Red Thunder, here we come! Cryptoengineer <treifamily@gmail.com> - 2015-09-12 21:43 -0500
      YASID:  Moon in a very low orbit. Greg Goss <gossg@gossg.org> - 2015-09-13 01:33 -0600
        Re: YASID:  Moon in a very low orbit. wdstarr@panix.com (William December Starr) - 2015-09-13 03:51 -0400
          Re: YASID:  Moon in a very low orbit. tmcd@panix.com (Tim McDaniel) - 2015-09-20 23:23 +0000
            Re: YASID:  Moon in a very low orbit. Cryptoengineer <treifamily@gmail.com> - 2015-09-20 19:56 -0500
              Re: YASID:  Moon in a very low orbit. Robert Carnegie <rja.carnegie@excite.com> - 2015-09-20 20:18 -0700
              Re: YASID:  Moon in a very low orbit. tmcd@panix.com (Tim McDaniel) - 2015-09-22 05:46 +0000
                Re: YASID:  Moon in a very low orbit. "J. Clarke" <j.clarke.873638@gmail.com> - 2015-09-22 04:04 -0400
        Re: YASID:  Moon in a very low orbit. Cryptoengineer <treifamily@gmail.com> - 2015-09-13 10:31 -0500
          Re: YASID:  Moon in a very low orbit. "Michael R N Dolbear" <me@privacy.net> - 2015-09-13 19:41 +0100
            Re: YASID:  Moon in a very low orbit. Cryptoengineer <treifamily@gmail.com> - 2015-09-13 21:15 -0500
              Re: YASID:  Moon in a very low orbit. "J. Clarke" <j.clarke.873638@gmail.com> - 2015-09-14 06:05 -0400
                Re: YASID: Moon in a very low orbit. Dimensional Traveler <dtravel@sonic.net> - 2015-09-14 18:47 -0700
          Re: YASID:  Moon in a very low orbit. Robert Carnegie <rja.carnegie@excite.com> - 2015-09-13 21:49 -0700
            Re: YASID:  Moon in a very low orbit. Greg Goss <gossg@gossg.org> - 2015-09-14 10:21 -0600
              Re: YASID: Moon in a very low orbit. nebusj-@-rpi-.edu (Joseph Nebus) - 2015-09-14 20:26 +0000
  Re: Red Thunder, here we come! Robert Bannister <robban@clubtelco.com> - 2015-09-14 11:43 +0800
    Re: Red Thunder, here we come! "J. Clarke" <j.clarke.873638@gmail.com> - 2015-09-14 06:16 -0400
      Re: Red Thunder, here we come! "Brian M. Scott" <b.scott@csuohio.edu> - 2015-09-14 06:24 -0400

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