From: Camaronat.1sunlr@spacebanter.com   
      
   Everything has pretty much been covered, but there are a couple of   
   things to consider.   
      
   First, the big reason why we still use conventional rockets over   
   spaceplanes is weight. Weight is the big killer. In a rocket, your   
   weight is basically broken up into outer structure, engine, payload,   
   payload adapter, electronics, and fuel. In a spaceplane, you have all   
   of the same stuff to deal with as a rocket, but you also have extra   
   weight in your structure, an air breathing engine, and fuel for that   
   engine. It is just more economical, at the moment, to use rockets.   
      
   Second, SpaceShip One didn't need to worry about heat shielding because   
   of its design, as personaljazz said. The increased drag slows down the   
   craft much faster, and as a result, it doesn't heat up. The Mercury   
   pods used heat shielding, and Alan Shepard's flight reached about   
   5000mph.   
      
      
   --   
   Camaronat   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)