From: henry@spsystems.net   
      
   In article <20040225214026.20206.00000476@mb-m27.aol.com>,   
   Allen Meece  wrote:   
   >   That was how the old DynaSoar was going to do it. Quick little dips down   
   >into thick air to scrub some speed but then skipping back up into thinner air   
   >to cool off a bit before gliding back down.   
      
   Unfortunately, while this may improve the thermal situation somewhat --   
   it's not as clear-cut as the Dyna-Soar promoters thought -- it doesn't   
   actually help the aerodynamics.  To achieve the same duration of flight,   
   you need the same L/D.  Averaged over one cycle, you need the same amount   
   of lift, and hence at the same L/D, you will incur the same amount of   
   drag.   
      
   >   I think that's how civilian entrepreneurs will design their reentry ships -   
   >more like an airplane than a bowling pin.   
      
   There's no such pattern visible in how civilian entrepreneurs have   
   designed their vehicles to date.  A long, slow, high-L/D reentry has   
   major disadvantages as well as advantages.   
   --   
   MOST launched 30 June; science observations running     |   Henry Spencer   
   since Oct; first surprises seen; papers pending.        | henry@spsystems.net   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)