From: henry@spsystems.net   
      
   In article ,   
   Ian Woollard   wrote:   
   >> It could only work for that short period of time the craft was still in   
   >> useful air.   
   >   
   >Clearly, however the ISP over that time is extremely high for a solid,   
   >and reduces the GLOW of the vehicle quite a bit...   
      
   And we care about that... why, exactly?   
      
   A great many misconceptions, superstitions, and outright myths about   
   launcher design can be traced to the habit -- inappropriately inherited   
   from the missile business -- of thinking of gross liftoff weight as an   
   important figure of merit.   
      
   Especially when the reduction in weight is coming out of the propellants,   
   the cheapest and most easily-designed part of the whole vehicle.   
      
   "Gross weight is not a primary consideration in the design of space   
   vehicles... paper studies based on weight optimization have ... vastly   
   overrated the importance of weight, particularly for the booster stage,   
   which is of course the heaviest stage..."  -- Del Tischler, 1962   
      
   --   
   MOST launched 30 June; science observations running     |   Henry Spencer   
   since Oct; first surprises seen; papers pending.        | henry@spsystems.net   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)