From: zenadsl6186@zen.co.uk   
      
   Rüdiger Klaehn wrote:   
      
   > Peter Fairbrother schrieb:   
   >> Rüdiger Klaehn wrote:   
      
   >>> 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.   
      
   >> First, I doubt that - what if a child runs out on the landing field?   
      
   > That is a silly argument. That has nothing to do with the reliability of   
   > the vehicle.   
      
   Got a lot to do with the safety of the system though. The child was only an   
   example - what if the landing zone is on fire?   
      
   (yes, that's also a somewhat unlikely example, chosen to make a point though   
   - we should be talking about the level of safety where such unlikely events   
   matter, as they do in aviation safety)   
      
   > I guess trains are too dangerous for the general public   
   > too, since when a child runs on the tracks in front of a train it dies.   
      
   If a child gets on a runway the aircraft landing can be aborted - or if the   
   runway is blocked for any other reason - but that doesn't work with rocket   
   landing.   
      
   I was thinking about it from the somewhat analoguos pov of a helicopter   
   pilot. Every helicopter pilot I know has had to abort a landing at least   
   once because some idiot was on the pad, and most of them have also had to   
   abort because the pad was obstructed or unsafe for some other reason - and   
   for some busy pilots it happens at least once a year.   
      
   They just fly around for a bit and swear, or go to a different landing site   
   - but a rocket powered lander can't do that.   
      
   >> what if   
   >> you miss the field and are committed to landing in a built-up area? Powered   
   >> wings and wheels avoid that situation.   
      
   > A vertical landing rocketship can land on any flat area, as the DC-X   
   > proved.   
      
   Eh?   
      
   And are you talking about landing on wide open spaces, like the Russian   
   steppe?   
      
   > And you won't land your rocketships in the middle of a city anyway.   
      
   I don't see why not, for instance London City Airport would be a fine place   
   to land my people carrier. And then step into the waiting limo.   
      
   London City is too short for takeoff though, and Heathrow would be too   
   expensive, so perhaps Gatwick or even Luton would be chosen.   
      
   But you could land at LC, deplane the passengers, refuel and add some   
   temporary fuel tanks, and then fly the orbiter to a suitable takeoff site   
   under it's own power if you really wanted to, say if the Queen was on board.   
      
   >> and second, who's doing safe controlled rocket powered landings right now?   
   >>   
   > So?   
      
   Wings can give a decent payload fraction, and they already work safely.   
      
   No need to waste resources on developing a new, expensive and intrinsically   
   unsafe technology when we have a perfectly acceptable and safe landing   
   technology already.   
      
      
      
   I do not believe vertical rocket landing is ever going to be as safe as   
   powered winged landing. Further, effort spent on it is a waste of resources   
   - there is no need for it.   
      
   It might be cool, but you don't need vertical rocket landing on Earth,   
   certainly not now, and for passenger safety you probably never will.   
      
      
   --   
   Peter Fairbrother   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)