OTA@S1-A@sri-unix (11/25/82)
From: Ted Anderson <OTA@S1-A>
SPACE Digest Volume 3 : Issue 53
Today's Topics:
Space may be for the rich after all... (JS&A)
Spacecraft environments
Low-pressure suits
Air Pressure in suits.
Piggyback Delayed
Pressureless Suits
Shuttle Arrives at KSC on Time After All
You could look it up
Oxygen use at low pressures
Shuttle Software
NASA as a Pollyanna
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Date: 22 Nov 1982 0739-PST
Sender: WMARTIN at OFFICE-8
Subject: Space may be for the rich after all... (JS&A)
From: WMartin at Office-8 (Will Martin)
To: space at MIT-MC
Message-ID: <[OFFICE-8]22-Nov-82 07:39:44.WMARTIN>
Received my JS&A catalog and have more info on the "shuttle
passenger" contest/lottery/whatever:
It doesn't cost anything to enter. If you don't want to buy the
poster and certificate, you just send in your name and address to
get notified when they have more concrete information. (If you
don't buy anything, I don't know how carefully they will preserve
this name & address, but who knows...?) The certificate is a
thing with your name that says you have a reservation for
consideration on the first passenger flight, plus various fine
print which legally absolves them from doing anything. The
poster is a silly-looking picture of a bunch of planets hanging in
space, all close together in a totally unrealistic and impossible
manner. Poster and certificate are $30, $20 if you buy anything
else, too. They look to me to be worth something less than $2.00,
actually...
OK, so what do you get if you "win"? Reading the catalog page
and picking out the real meaning from the verbiage, it looks like
you get a chance to spend upwards of $5,000 to pay your way.
They compare it to the cost of an "around-the-world" tour (which
it is, actually, I guess...). This factor was not mentioned to
me by the person on the phone when I asked them about it, nor was
it in the news items I heard or read.
All in all, it sounds much like a scheme to sell overpriced
posters...
Disillusionedly,
Will Martin
------------------------------
Mail-From: CMUFTP host CMU-CS-IUS received by CMU-10A at 22-Nov-82 13:43:41-EST
Date: 22 Nov 1982 13:26:38-EST
From: Wilson.Harvey at CMU-CS-IUS at CMU-CS-A
To: space@mit-mc@cmua
Subject: Spacecraft environments
I remember a few years back, when the Apollo-Soyuz mission was about to take
place, that one of the big problems with linking the two spacecraft was the
Soviets used a different environment in their cabins. Namely, I thought
that their cabin environment was close to 'normal' earth environment i.e. a
mixture of Carbon Dioxide, Nitrogen, and Oxygen. I don't remember what the
pressures were. I was just wondering why we use an environment of ~100%
Oxygen and the Soviets used a different one. What are the benefits, if any,
of the one over the other. (I do remember that the Soviets could perform
welding experiments in space where we could not). Can anyone else confirm
this, or am I totally out of the ballpark?
Thanks,
Wilson
------------------------------
Date: 22 November 1982 1413-EST (Monday)
From: David.Smith at CMU-CS-A (C410DS30)
To: Steven Gutfreund <gutfreund.umass-coins at UDel-Relay>
Subject: Low-pressure suits
I see that my statement about boiling blood has been defended better than
I could have myself. But let me point out that boiling has to do with the
fluid's vapor pressure matching the ambient gas pressure. You can boil
water either by raising its vapor pressure (by heating it),
or by reducing the required vapor pressure (by lowering the ambient gas
pressure).
Back in the early '60s, National Geographic ran an article called
"The Long, Lonely Leap." It was about a fellow named Kittinger who
tested a new high-altitude parachute system by jumping from a balloon
at 102,000 ft. As he jumped, or just before, one of his gloves lost
pressure. He landed with a hand painfully swollen to the point of
unusability. I think it took something like four hours for his hand
to recover.
Here are some standard atmospheric pressures taken from the Handbook of
Chemistry and Physics. (Sea level pressure is > 1000 millibar because
the assumed sea level temperature is the pilot's 59F standard.)
Altitude Pressure
Meters Feet millibars psi
-------------------------------
0 0 1013.25 14.84
11000 36089 226.32 3.315
20000 65617 54.748 .802
32000 104987 8.678 .127
47000 154200 1.204 .0176
75000 246062 .0245 3.59e-4
This shows that the 60000 or 63000 foot level provides considerably less
pressure than is in the astronauts' suits, even with Lenoir's down to
3.7 psi.
If we use this sea-level pressure and the 21% oxygen figure, we get an
oxygen partial-pressure of 3.1 psi. So the astronauts are running a bit
rich. Maybe they could use 3.1 psi of O2, plus another pound of N2, if
they want the suits over 4 psi. On the other hand, maybe they need the
oxygen. During Gemini, astronauts tended to fog up their face plates
while trying to do real work.
David Smith
------------------------------
Date: 22 Nov 1982 1803-EST
From: Tony <Li at RUTGERS>
Subject: Air Pressure in suits.
The air pressure on earth decreases roughly by one p.s.i. per
thousand feet. Thus, the 4.2 p.s.i. is roughly about what you would
experience at 11,000 feet. This is certainly acceptable for work, but
you wouldn't want to do any wind sprints. :-)
------------------------------
Date: 22 Nov 82 7:28:22-PST (Mon)
To: space at Mit-Mc
From: harpo!npoiv!alice!sjb at Ucb-C70
Subject: Piggyback Delayed
Article-I.D.: alice.1186
Via: Usenet; 22 Nov 82 18:16-PST
The Columbia completed part one of its flight back to KSC yesterday,
as its 747 landed at Kelly AFB in Texas for refueling. But bad weather
there has forced postponement by one day of the last leg of the trip,
now set to land at KSC tomorrow. Meanwhile, the Challenger's rollout
to the VAB is now scheduled for no earlier than 1800 EST today, due
to delays with a hydraulic line.
------------------------------
Date: 22 Nov 82 22:32-EST (Mon)
From: Steven Gutfreund <gutfreund.umass-coins@UDel-Relay>
To: space at Mit-Mc
cc: david.smith at Cmu-10a
Subject: Pressureless Suits
Via: UMASS-COINS; 23 Nov 82 0:59-EST
I'm still not sure I have gotton a definitive answer on this:
1. The linear heuristic that the pilot gave for turning feet to
millibars of Hg, was obviously flawed. David.Smith's quotations
from the CRC are obviously more correct.
2. The comments about Dave of 2001, are not exactly relevent. I am
assuming a pressure helmet with some sort of seal that will work.
(BTW, I just saw this film last night again, and the scene is
pretty believable, I was just not sure how he positioned the pod
so well with no rear window).
The two major arguments against pressureless suits at this moment seem
to be: (1) without pressured suits, exhaling becomes too hard (2) Blood
starts boiling when the body is is exposed to vacuum.
Counter-arguments to (1)
(1) is a good argument, But humans are pretty good about building up
lung power for exhaling. Just look at Tuba players, people who can
do artificial respiration for hours, or those incredible bagpipe players.
I wonder if one could not train ones lungs to produce enough counter
pressure against 3.7 psi. If not, why not an elastic band around the
chest. This way, the 3.7 psi air forced into the lung will do work
which is stored in the band, which can then help the person exhale.
(2) Do you really think that if I put my hand in a vacuum bottle, my
blood will start to boil? Forget the misleading stuff about persperation,
and concetrate. Why is it that blood boils at lower pressures? Just
as David.Smith says: "it is a liquid immersed in a lower pressure
ambient environment". This can only be accomplished by the artery
and vein walls expanding. Will this really happen if a the body
is exposed to a mere 16psi differential? The balloonist falling from
102,000 probably had a severely swollen hand due to frostbite (but
I could be wrong).
I would not be surprized if pressureless suits are not realistic,
but I still think that the evidence has not yet been presented here
to shoot it down.
- Steven Gutfreund
------------------------------
Date: 22 Nov 82 16:11:07-PST (Mon)
To: space at Mit-Mc
From: harpo!eagle!mhtsa!alice!sjb at Ucb-C70
Subject: Shuttle Arrives at KSC on Time After All
Article-I.D.: alice.1188
Via: Usenet; 23 Nov 82 0:16-PST
The Columbia arrived at KSC today on time after all. The
storm front that NASA said would delay the arrival by a
day had dissipated by morning, and NASA decided to go ahead
and try to fly the remaining 3 hours to Canaveral.
------------------------------
Date: 22 Nov 82 17:35:45-PST (Mon)
To: space at Mit-Mc
From: harpo!ihnp4!ihuxr!lew at Ucb-C70
Subject: You could look it up
Article-I.D.: ihuxr.217
Via: Usenet; 23 Nov 82 2:02-PST
The 1973 edition of Encyclopedia Britannica contains the following
paragraphs in the article "Space Exploration", under the heading
"The Vacuum of Space":
Exposed to such a vacuum environment, the unprotected human being
would have less than 15 sec. of consciousness because of the swift
onset of acute hypoxia, and immediate, catastrophic decompression
symptoms including bends, chokes, palsies, and ebullism. The last
term is defined as the profuse evaporation or "boiling" of body fluids.
To protect the astronaut against the vacuum of space, typical U.S.
spacecraft are designed to contain a normal operating pressure of
5 psia (pounds per square inch, absolute) of 100% oxygen, and a
minimum emergency pressure of 3.5 psia.
---------------------------------------------
Some comments on other net.space submissions:
Venting your lungs would surely "freeze dry" them rapidly.
Your heart maintains a pressure DIFFERENCE between the venous and
arterial systems. It cannot pressurize the whole circulatory system.
Lew Mammel, Jr. ihuxr!lew
------------------------------
Date: 23 November 1982 05:21-EST
From: Robert Elton Maas <REM at MIT-MC>
Subject: Oxygen use at low pressures
To: harpo!npoiv!eisx!pyuxbb!jb at UCB-C70
cc: SPACE at MIT-MC
Thanks for the fine info. That sounds like a good manual.
One more question, does it say how long at zero pressure the human
body can remain before boiling of body fluids causes damage to the
body? (Like is it just a half second from vacuum to death, or could
somebody "hold their breath" for 5 seconds while turning the pressure
back on after an accidental depressurization?)
------------------------------
Date: 23 November 1982 05:32-EST
From: Robert Elton Maas <REM at MIT-MC>
Subject: Shuttle Software
To: gutfreund.umass-coins at UDEL-RELAY
cc: SPACE at MIT-MC
I think that's a great idea! I wonder if they also paid IBM for
finding bugs in Rockwell's software?
------------------------------
Date: 23 November 1982 05:38-EST
From: Robert Elton Maas <REM at MIT-MC>
Subject: NASA as a Pollyanna
To: decvax!utzoo!watmath!pcmcgeer at UCB-C70
cc: SPACE at MIT-MC
Date: 21 Nov 82 15:57:36-PST (Sun)
From: decvax!utzoo!watmath!pcmcgeer at Ucb-C70
Remember, in 1962 Gus Grissom lost his capsule on reentry,
and NASA still called the mission - with all data lost - a "total success".
Sigh, I must have missed that particular hype. Yeah, that one sure
beats the STS hype.
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End of SPACE Digest
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