From: vince@offshore.ai (Vincent Cate)
Newsgroups: sci.space.history
Subject: Re: How low can you orbit?
References: <sjq0nv8mbusgudf5obdbsqima54alg4nrb@4ax.com>
NNTP-Posting-Host: 209.88.68.230
Message-ID: <9186edb5.0310180749.60dc556e@posting.google.com>

Jan Philips <judmccrNOSPAMM@bellsouth.net> wrote in message news:<sjq0nv8mbusgudf5obdbsqima54alg4nrb@4ax.com>...
> Some of the early US manned orbital flights orbited only a little more
> than 100 miles up.  How low can you orbit?  What is the relationship
> between height and the maximum number of orbits?  For instance, if you
> go into a circular orbit at 100 miles, how many orbits can it stay in
> orbit?  Can you orbit at 95 miles?  Etc.

Thanks to Henry Spencer putting me on to a new atmospheric model,
I now have a simulator that matches orbital decay graphs in the books 
I have (3 sources) to within 25% or so. 

If anyone wants to play with it, it is a Java applet at:

 http://spacetethers.com/spacetethers.html

See samples 63 to 66.  It is easy to try out your own tests.

   -- Vince