[net.space] Pressureless Space Suits

gutfreund.umass-coins@UDel-Relay@sri-unix (11/20/82)

From:     Steven Gutfreund <gutfreund.umass-coins@UDel-Relay>
re: David.Smith's replies

o The CO (2) is necessary, but to prevent hypoventilation (as was pointed
  out to me, football players get oxygen with 5% CO (2) otherwise the
  breathing reflex is inhibited)

o The NYT reports that shuttle suits were supposed to be at 4.3 psi
  but even though Lenoirs suit only got up to 3.7 psi it was acceptable.

This gets me to my disagreement with you. I do not know what 3.7 psi
translates to in feet, but I would not be surprized if it is over
the 60,000 feet. (these things tend to go exponential)

You state that "at low enough pressure (above 60,000 feet), blood will
boil at body temperature". Well perhaps this would occur for blood
directly exposed to the atmosphere. But the human blood pressure is
maintained at a constant pressure by the heart and associated arterio/
vascular system, it does not matter what the pressure outside the skin
is.

The question to me seems to be: can the skin maintain a 16 psi pressure
differential without the body bloating up, aterial dialation, and
a massive drop in blood pressure. If so, then I maintain that
pressureless thermal spacesuits are a viable alternative.

I have remembered the SF story with astronauts that do not need
suits, it is in an anthology by Jerry Pournelle: "High Justice".
(I highly recommend this anthology for those who want to argue
about the economic viability of space).

Do you have any independent justification for pressureless space-suits
Jerry?

					- Steven Gutfreund