Eric Chomko wrote:
wrote:

: Eric Chomko wrote:
: Jorge R. Frank ) wrote:
: : (Eric Chomko) wrote in
: : :
:
: : But is money enough? I would agree that we could do a sample
: return
: : mission that was unmanned with today's technology, but could
be
: do an
: : manned mission, given the money, with today's technology?
: According to
: : a Science Channel program on nanotechnology, use in medicine
is
: not
: : there yet for a three year manned journey to Mars. Keeping
the
: : astronauts healthy during the three year journey there and
back
: would
: : require breakthroughs in nanotechnology in medicine that
doesn't
: exist
: : yet.
:
: : I suspect this is a case of "if the only tool you have is a
hammer,
: every
: : problem looks like a nail." Of *course* a nanotechnologist is
going
: to
: : claim that a Mars mission will require breakthroughs in
: nanotechnology -
: : it's the only way *he* knows to solve the problem. That does
not
: mean there
: : are no other solutions, and some of those solutions require no
: : breakthroughs in technology - just further development of
: technologies we
: : already have.
:
: How do you propose the astronauts overcome the problem with bone
and
: muscle degradation in zero gee for a Mars-lentgh mission?

: As others have suggested so many times before...

: Eliminate the zero gee with a two-part ship, joined by mile-long
: tethers, and spinning to produce 1 gee. Test first in LEO. No
: nanotech required.

Just a mile long? Yeah, "test" is the operative word here.

As it is for nanotech (with a vengeance). Tethers have some
advantages: they exist; tests are straight-forward (send up a
double-payload, spin slightly, unwind the tether, re-wind, unwind
again, throw in some vibration tests, move one of the masses, etc).
The possible failure modes for a tether aren't too hard to imagine and
so design a test for. Can you imagine the many ways nanotech in the
human body might fail or cause damage? Neither can I. And that's what
makes it difficult for you and I to design a test for nanotech.