From: jimdavis2@earthlink.net   
      
   Proponent!!!N0_SP@M!!!@gmx.net wrote:   
      
   > Watching the NH launch reminded me of a something that's been   
   > bothering me for a while: why is the arrangement of SRBs on the   
   > Atlas V asymmetric?   
      
   The arrangement is assymetric because there are two external fittings   
   on the Atlas V common booster core, an avionics pod and an LO2   
   feedline. These are at about the 10:30 and 1:30 positions. Two of the   
   solids are between these fittings at about the 11:30 and 12:30   
   positions. The other 3 are on the opposite side at the 5, 6, and 7   
   o'clock positions.   
      
   > How is the asymmetry of the SRB thrust   
   > compensated for? By gimballing the RD-180s?   
      
   Presumably.   
      
   > ...isn't this inefficient?   
      
   Not really. The shuttle does exactly this. Another possibility is   
   canting the solid booster nozzles differently to compensate for the   
   assymetry.   
      
   Jim Davis   
      
   --- SoupGate-Win32 v1.05   
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