From: ianrsturdy@gmail.com   
      
   All those radiators seem to be operating at rather low temperatures--if you   
   could run at 2900K instead of 1450K, you would only need 1/16th the radiator   
   area. I expect a beryllium phase-change radiator would operate close to its   
   boiling point of 2742K,    
   giving a sizable advantage. Given also that the molybdenum/lithium radiator is   
   four times the weight per heat capacity as the best radiators on that page,   
   which also operate at low temperatures, I would not be surprised if much   
   better were possible.   
      
   I also expect your 20% estimate to be high--the trick in fusion engines seems   
   to be running the fusion reaction very far from any solid components. The   
   Firefly certainly seems to be designed around that, with the very narrow body   
   and conical tail    
   minimizing its apparent aspect. Moreover, 50% of your waste heat is x-rays,   
   which will not be completely absorbed by small thicknesses of matter.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)