From: klaehn@gamemakers.de   
      
   Peter Fairbrother schrieb:   
   > Henry Spencer wrote:   
   >   
    > Why?   
      
   You still have not answered why wings and wheels are the only safe   
   technology for landing. Even if we accept the very unrealistic   
   assumption that a space transport must be safe as commercial airliners,   
   there is no technical reason that you can not get very high safety with   
   rocket powered landing.   
      
   The key to high safety is redundancy. A capsule with many small rocket   
   engines for landing can be very reliable. For maximum reliability you   
   would run all rocket engines on idle during the landing and then   
   throttle up some of them to decelerate and land. If you have 12 rocket   
   engines and need only 4 of them to land, the chances of a failure are   
   extremely low. You just have to make sure that the engines do not have a   
   catastrophic failure mode.   
      
   You might argue that relying on complex active systems for a safe   
   landing is unacceptable, but then a starting airplane would be   
   unacceptable too. When a starting airplane were to lose all engines   
   during takeoff, it would certainly crash. But the chances of this are   
   extremely small with multi-engine airplanes. And (especially   
   pressure-fed) rocket engines are much less complex and less dependent on   
   the environment than aircraft turbofan engines. At least you don't have   
   to worry about birdstrike :-)   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)