From: mjessick@verizon.net   
      
   Parallax wrote:   
   > Actually the derivation in my 20 yr old physics text neglected   
   > gravity.  However, the point about raising the fuel to a higher   
   > potential seems like good reasoning.  Is there some way to optimize   
   > the use of fuel by means of repeated "detonations" to get more v out   
   > than you would get by expending fuel constantly?  I assume that the   
   > limiting factor is the acceleration the payload can handle.   
      
   If you burn in short bursts each time you swing around at periapsis   
   then you will get the most energy out of a fixed delta velocity.   
   (because you are burning at a higher average speed, and the   
   derivative of energy gain with delta velocity is proportional   
   to velocity.)  Of course it takes a lot longer. ;)   
      
   Coasts between the solid rocket motor burns on the IUS   
   sending Magellan, Galileo and Ulysses away from the Earth   
   were made as short as possible because of this effect.   
   (The longer the coast, the slower you are when the second   
   burn ignites as your radius increases as you coast upward   
   after the first burn.)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)