From: g_d_pusch_remove_underscores@xnet.com   
      
   zoltanccc@aol.com (Zoltan Szakaly) writes:   
      
   > I have a feeling that now that we have had a couple of shuttle   
   > accidents we are moving away from the shuttle too eagerly.   
      
   The Scuttle has almost _NOTHING_ going in its favor except that it's   
   a devil that we know, as opposed to a devil that we don't know.   
   Furthermore, given the CAIB's recommendation of a _COMPLETE_ flight   
   recertification of the Scuttles before they is allowed to fly again,   
   it is not impossible that no Scuttle may _EVER_ fly again !!!   
      
      
   > If I had to go to the Moon today, I would try to work as much as   
   > possible with the systems we have, like for example the shuttle.   
      
   Why?  What possible benefit could you gain buy using the Scuttle?   
   It can only lift payloads of limited mass and size, and once you   
   subtract the government subsidy, for most payloads expendables   
   are cheaper and more reliable!   
      
      
   > It would probably make sense to build a lunar access vehicle that   
   > would be launched from the shuttle's cargo bay and would go to the   
   > moon and land, then come back.   
      
   NASA will probably _NEVER_ allow any chemically fueled rocket booster   
   inside the Scuttle's cargo bay again. Your tug would have to be launched   
   with dry tanks, and fueled in orbit --- and NASA also appears to be   
   noticably frightened of attempting in-orbit fuel transfers.   
      
      
   > The mass ratio requirement for such a vehicle is such that it is doable   
   > in a single stage. Since this is done in space, perhaps ion engines could   
   > be used for orbital changes, like trans lunar injection. This would   
   > involve spiraling out to get to the Moon's orbit. A mass ratio of 5 would   
   > be enough to land on the Moon and take off to lunar orbit.   
      
   1.)  As has been discussed here many times before, such low-thrust   
     "spiraling" is a _REALLY_ Bad Idea --- the vehicle spends =FAR= too much   
     time soaking in the Van Allen Belts.   
      
   2.)  Ion rockets have such a low thrust-to-mass ratio that it is   
     _PHYSICALLY IMPOSSIBLE_ for an ion-powered rocket to land on the moon   
     --- so your lunar tug will _HAVE_ to have a chemically fueled rocket   
     for landing --- and NASA will _NEVER_ allow its fuel in the cargo bay   
     of a Scuttle.   
      
      
   > Existing expandables could be used to launch supplies habitats etc in   
   > the same general area on the surface of the Moon. These supplies could   
   > also be flown with ion engines.   
      
   Again, ion engines =CANNOT= be used to land on the Moon; they simply do not   
   have a large enough thrust-to-mass ratio.   
      
      
   > I guess my point is that once we have people in orbit it is not such a   
   > big deal to put them onto the Moon. The mass ratio/delta V requirements   
   > are reasonable. We would just need to design something like a LEM.   
      
   Again, NASA would _NEVER_ allow it to be launched in the Scuttle's   
   cargo pay unless it were launched empty and fueld in orbit ---   
   and they also appear to be scared of on-orbit refueling.   
      
      
   -- Gordon D. Pusch   
      
   perl -e '$_ = "gdpusch\@NO.xnet.SPAM.com\n"; s/NO\.//; s/SPAM\.//; print;'   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)