XPost: sci.chem, sci.physics, sci.space.policy   
   From: rgregoryclark@gmSPAMBLOCKail.com   
      
   A problem with scramjets, which attempt to achieve combustion at hypersonic   
   speeds, is that the high speed means the air is producing so much drag that   
   it is difficult to achieve net thrust when combusting with just the oxygen   
   in the air.   
      
   So what if we also combusted with the nitrogen? Nitrogen makes up 80% of the   
   air mass so perhaps this could provide sufficient thrust. The problem is   
   nitrogen is commonly present in the atmosphere as N2, a molecule that is   
   very stable, i.e., non-reactive.   
      
   But at hypersonic speeds so much heat is produced that the N2 is "cracked",   
   generating various nitrogen species, such as N, NO, NO2, etc.   
      
   So how much energy could be produced by reacting hydrogen fuel with the   
   various nitrogen species? How much for methane fuel?   
      
   The energy density and thus Isp would be less than for reacting with oxygen   
   but conceivable the thrust could be greater because of the greater mass of   
   the nitrogen.   
      
     Bob Clark   
      
   ------------------------------------------------------------------   
   Single-stage-to-orbit was already shown possible 50 years ago   
   with the Titan II first stage.   
   In fact, contrary to popular belief SSTO's are actually easy.   
   Just use the most efficient engines and stages at the same time,   
   and the result will automatically be SSTO.   
   Blog: Http://Exoscientist.blogspot.com   
   ------------------------------------------------------------------   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)