From: ben@vipmail.com   
      
   Of possible interest, it is my understanding that because of gravity, the   
   Martian atmosphere extends further from the ground then Earths, so any long   
   term orbit would necessarily need to be higher to avoid significant drag.   
   400 kilometers might not be a good place to park your crew return vehicle,   
   for example, unless you were confident that it could be reliably reboosted   
   as needed.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)