From: rijrunner@frii.com   
      
   Jon Berndt wrote:   
   > [from s.s.shuttle discussion]   
      
   snip   
      
   > Say the balloon is filled with helium.  At the surface conditions of -60   
   > degrees C, and  6 mb pressure, the density of He gas is 0.00184 kg/m^3 (??).   
   > The mass of the enclosed Helium would then be 7.7 kg.  So, the net buoyant   
   > force on Mars would be (83.8 - 7.7) * 3.71 = 282 N (63 pounds).  You'd have   
   > to account for the weight of the balloon itself, of course.   
   >   
   > Is this close to being accurate?  I haven't done anything like this in a   
   > while.   
   >   
      
      
      Any particular reason you chose Helium? Hydrogen is nonflamable   
   in the martian atmosphere.   
      
      
      Your numbers look pretty close, btw.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)