[extropy-chat] Re: SPACE: Back to the Moon (?)

[Christian Weisgerber]

Robert J. Bradbury <extropy-chat at lists.extropy.org> wrote:

> Why not a simple production plant to crank out either sheet silicon
> or titanium -- plenty of both up there.  Welding titanium is a bit
> tricky but ought to eliminate the loss of gas problem Eugen was
> discussing.

What's tricky about welding titanium other than that you can't do
it in an Earth-style atmosphere?  (Titanium burns with both oxygen
and nitrogen.)

> Since you have to separate O2 from the Si/Ti anyway,
> it isn't going to be the problem.  Its N2 that is going to be the
> problem.  Now of course one could substitute He3 which there is
> a fair amount of and one wants to mine anyway for its use in fusion
> reactors.  Downsides would be that the astronauts would talk funny
> and He3 is moderately radioactive.

He3 is a stable isotope, check WebElements.  (Maybe you are confusing
it with tritium which decays into He3?)  Helium has a much higher
thermal conductivity than plain air (approx. nitrogen).  You'll
have to ask a deep-sea diver whether this is actually as much a
problem as Michael Crichton makes it out to be in _Sphere_.

-- 
Christian "naddy" Weisgerber                          naddy at mips.inka.de