XPost: sci.space.shuttle, sci.space.history, rec.aviation.military   
   From: williamsonONETHIRTY@earthlinkdotnet.retro.com   
      
   tomcat wrote:   
   > delt0r wrote:   
   >   
   >>Assuming that you are asking "why not the NASP".....   
   >>   
   >>What is about aircraft that fly in a atmosphere that make people that   
   >>they are anygood for a space craft?   
   >>   
   >>Wings are not a good thing when there is no air or your going kinda   
   >>fast, eps if your on a budget and don't need cross range.   
   >>   
   >>Non wing based SSTO or any other kind of xxTO  will be cheaper and   
   >>easier than a winged one.   
   >>We are not flying... we'er orbiting.   
   >>   
   >>All IMHO of course (or IMO if you prefer)   
   >   
   >   
   >   
   >   
   > Wings use air to gain an advantage on gravity.  Therefore, they can   
   > reach the airless void using less energy than a vertical tublular   
   > rocket.  They also enable a spacecraft to 'fly' to a runway and land   
   > softly after deorbit.  Wings are unnecessary for a spacecraft that is   
   > not designed for, and never intended for, planetary takeoff or   
   > planetfall.   
      
      
      Wings do not allow for less energy to be used to orbit a craft- while   
   they provide lift they do not provide any energy.  In fact, since they   
   also generate drag, a winged vehicle would almost certainly require   
   more fuel to reach orbit, since the tubular design will have less   
   drag to overcome.  The wings are only useful during the descent and   
   landing stage, where they allow you more options for a landing point,   
   such as using a runway or some other point farther from the ground   
   track of your orbit.   
      
   >   
   > The proof that wings gain an advantage is that a bomber can reach   
   > 20,000 feet and stay there for the hours it takes to reach target and   
   > return on 1/10th of the thrust to weight ratio that a vertical tubular   
   > rocket requires just to slowly leave the launch pad.   
      
      This is totally irrelevant to wings being used on a spacecraft.  While   
   they do allow aircraft to fly with lower thrust to weight ratios, that   
   has nothing to do with the fuel required to put a payload in orbit.   
   Heck, in your example, most of that fuel is burned in cruise, during   
   which you aren't even adding speed or altitude (i.e. energy) to the   
   aircraft- you are just replacing that lost to drag.  On a vertical   
   launch, as you go higher you have less atmospheric drag to contend   
   with- winged or not.   
      
   >   
   > Air molecules are compressed by gravity and that compression gives lift   
   > with a properly designed airfoil.   
      
      This is utter nonsense.  An airfoil will produce lift through forward   
   motion whether the air is "compressed by gravity" or not.  The lift   
   is determined by the density of the fluid (air in this case), not by   
   how it got to be that dense.   
      
   Mike   
      
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