From: henry@spsystems.net (Henry Spencer)
Newsgroups: sci.space.tech,sci.space.policy
Subject: Re: Space station question
Date: Wed, 17 Feb 1999 03:48:32 GMT

In article <7acjg2$aqk$1@nnrp1.dejanews.com>,
 <patrick.underwood@natinst.com> wrote:
>Surgery, major or minor, is pretty much impossible in zero-g.  If an
>astronaut on the way to Mars has a problem requiring major surgery asap, he's
>dead.  For starters, just think about the blood that would float--nay, be
>PUMPED--out of a medium-sized thorasic incision in microgravity.

While control of bleeding would certainly be a problem, it can be a
problem even on Earth.  Gravity doesn't help *that* much in restraining
blood flow; the pressure required to get blood to your head is much
higher than that required to get it to the surface of such an incision.

By the way, fluids generally do not float away from solid surfaces at
all, by themselves.  They cling, due to surface tension.

>Food handling, sleeping, working with tools, going to the bathroom--virtually
>every aspect of life is negatively affected by zero-g and requires adaptation
>and training on the part of astronauts.

This is greatly exaggerated.  Food handling in free fall is almost
identical to that on Earth; in fact, almost all of the fancy ideas for
special eating utensils, dishes, etc. turned out to be entirely
unnecessary.  Ditto sleeping.  The only big issue in working with tools is
that if you want to stay fixed in one place to do *anything*, you need
restraints to keep you there; the restraints needed to keep you near your
work suffice to deal with the side effects of tool use, and again, almost
all the work on special space tools was completely pointless.  Going to
the bathroom needs careful attention to the design of the facilities but
is otherwise not very exotic.  And so forth.

The astronauts, almost unanimously, *like* free fall.

>Astronauts detect a decrease in their sense of taste, and often get stuffy
>heads, because of changes in blood distribution in microgravity.

The Russians experimented, apparently successfully, with avoiding this
problem (the upward shift of body fluids) by taking diuretics for a day
or two before flight to reduce the body fluid load.

(The decrease in sense of taste is not mysterious, or not very anyway.
The fluid shift does indeed tend to cause stuffed-up noses... and quite a
bit of our sense of taste is really smell.  A bad head cold will likewise
considerably impair your sense of taste.)

>And every one of these problems could be eliminated or minimized by using
>rotating spacecraft or stations.

Only if they were very large ones, due to the inner-ear problems of
rotation.  And that solution is not available -- or at least, much less
practical -- on the surface of the Moon or Mars.  If the problems of
free fall can be solved, that would be a simpler solution.
--
The good old days                   |  Henry Spencer   henry@spsystems.net
weren't.                            |      (aka henry@zoo.toronto.edu)