From: LFLekx@NOSPAM.rogers.com.retro.com   
      
   On 08 Jan 2005 22:07:32 GMT, Ian Stirling    
   wrote:   
      
   >> payload... and that's not counting the benefits of getting rid of the   
   >> insulation.  (Mainly because I have *no* idea of how much of a weight   
   >> decrease that would be...)   
   >You're going to need to beef up the structure, as the kerosene-filled   
   >(well, not filled) tank is a fair bit heavier.   
      
      Of course, the fuel tank could be reduced in size, and the volume   
   savings could go into strengthening the tank walls.   
      
      The structure wouldn't have to be beefed up *too* much, since JP-5   
   is actually *less* dense than liquid O2.  The peroxide (formerly   
   hydrogen) tank might benefit more from the strengthening, since it'll   
   be carrying a fluid that's twenty-odd times more dense than what it   
   was carrying before...  :-)   
      
   >Where do the SRBs go?   
   >Outboard of the existing ones?   
      
      Only run some numbers on thrust, fuel-consumption, and Delta-V thus   
   far - hadn't given that much consideration.  Likely, shift the   
   existing two a bit closer to the orbiter, and mount the new pair   
   similarly on the tank.  That would keep the thrust-vector in   
   more-or-less the same place.  This means they'd probably have to be   
   dropped sequentially - the pair farthest from the orbiter first, and   
   the second pair when those are clear.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)