From: tanada@provide.net   
      
   >> On the other hand, a fixed-wing aircraft.i.e. the B-70, can indeed be   
   >> designed to carry a large payload at high altitude. While a large blunt   
   >> cone would have to much drag for external carriage on an aircraft, a   
   >> saucer-shaped vehicle could be carried and launched edge first and   
   >> re-enter flat side first; this is pretty much what Rutan's SpaceShip   
   >> One does with its pivoting tail. This can spread the heating over a   
   >> large area as with the Apollo Capsule, reducing thermal loads.   
   >   
   > The airplane is superior to rocket as a means of transportation   
   > through the troposphere because it is slower and much more   
   > reusable. It is however not as slow as the helicopter, and   
   > the separation of the rocket launcher and its cargo from the   
   > airplane is tricky due to the aerodynamic drag.   
      
   However, so long as the aircraft is designed with a thrust to weigth ratio   
   greater than 1:1 when loaded with the payload at altitude it can hover   
   vertically on its tail during the seperation manuver.  The aircraft flies up   
   to launch altitude, goes vertical, releases the payload while hovering.  The   
   payload ignites its next stage, the aircraft reduces throttle allowing   
   itself to tip over and power glide most of the way back to the launch site   
   with the engines at idle.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)