From: LFLekx@NOSPAM.rogers.com.retro.com   
      
   On Thu, 3 Feb 2005 16:03:29 GMT, henry@spsystems.net (Henry Spencer)   
   wrote:   
      
   >There is no way that solid-core nuclear can do 100km/s.  Even gas-core   
   >probably tops out around 50km/s.  100km/s or more should be feasible with   
   >systems that don't try to separate fission fuel and propellant -- NSWR or   
   >imploded-pellet fission, for example -- but operating costs will be high   
   >and the exhaust generally rather dirty.   
      
      This is rather old, and I doubt much research has gone into it...   
   but if it could be developed, it would be an *immense* improvement in   
   rocket technology...   
      
      From an article by Jerry Pournelle...   
      
          "Take Boron-11 (11B5).  Bombard with protons.  The result is a   
   complex reaction that ends with helium and no nuclear particles.  It   
   could be a direct spacedrive.  For those interested, the basic   
   equation is   
      
             11B5 + p = 3(4He2) + 16MeV   
      
        and 16 million electron volts gives pretty energetic helium.  The   
   exhaust velocity is better than 10,000 kilometers/second, giving a   
   theoretical specific impulse of something over a million."   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)