From: zenadsl6186@zen.co.uk   
      
   Henry Spencer wrote:   
      
   > Peter Fairbrother wrote:   
      
   >> Powered-wings-and-wheels on a runway is about the only method presently   
   >> approved for scheduled public passenger transportation.   
   >   
   > You are confusing what is approved for aviation (and even that includes   
   > a somewhat broader range of approaches than you claim) with what is   
   > acceptable for spaceflight.  Spaceflight, even tourist spaceflight, will   
   > not soon reach the level of safety achieved in aviation,   
      
   I disagree, and more, I think that's the wrong attitude. Why should   
   spaceflight be significantly less safe than air travel? It doesn't have to   
   be.   
      
   Tourists want a safe holiday. "As safe as commercial aviation" is not really   
   enough, it should be _safer_, as you are charging a whole lot, and thus   
   should be attracting the rich who will have enough money to choose the   
   safest airlines, or even have ther own bizjets when they want to fly.   
      
   > and it won't   
   > necessarily get there by using the same methods either.   
      
   Perhaps not, but we have the powered-wheeled-landing technology and   
   infrastructure in place already, and it's all approved and ready to go.   
      
   About the only disadvantage of PWL is that wings and wheels and engines   
   weigh a lot, which messes up the MR of the second stage (we are only talking   
   about 2-stages here, I assume, as nothing else is likely to be as   
   economical).   
      
   Agreed, for cargo wings, wheels and engines make little sense due to the   
   extra weight; but for passengers that doesn't matter a lot, the life support   
   and safety equipment, the seats, lifejackets, washable plastic decorative   
   interior, bulletproof lockable cockpit door and so on weigh more than the   
   weight of the wings wheels and jets, and all that has to go up too.   
      
   The passengers themselves weigh comparatively little, and the extra weight   
   of wings, wheels and engines doesn't matter that much, as long as you are   
   trying to get passengers into orbit and back, and not payload, or not trying   
   to do both.   
      
      
   The problem with private space travel is the large investment needed, and   
   the main difficulties there are political, not financial or technological,   
   and off-topic here. Safe and profitable orbital tourism will take a minimum   
   investment of at least 1.5 billion, and 10 billion would be better. Sounds a   
   lot, but it's about the same as the development cost of a major new   
   airliner[1]. Boeing for instance could easily raise that much, as could   
   several other firms or consortia.   
      
      
   [1] Building a 2-stage space transport system is technologically quite   
   similar to developing one-and-a-half new airliners, and then building a few   
   of them; but it can be done quite a lot cheaper.   
      
   You are only going to build a few, so tooling life can be shorter, which   
   saves a little: infrastructure is less, you don't have to build and staff a   
   large production line, which saves more than a little; and you do not have   
   to compete with highly and expensively developed present airliners   
   (spacecraft) - you are not trying to make a better spacecraft, you are only   
   trying to make a working spacecraft - which saves a whole lot. Investing   
   that extra billion to get a few more seats in or the fuel consumption down a   
   little is not needed.   
      
      
   --   
   Peter Fairbrother   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)