Rene-NASA-Mooned-America

Blowholes Of Sea & Space / Chap. 12 p. 101
368 watts. 6 This should be added to the Sun's heat value for a total heat input of 571 watts. 7
However we should calculate the heat radiated by the shady side of the suit. Before
proceeding we must determine a temperature for the air in the suit. The higher the temperature,
the easier it is for the air cooler to do the job. Let's assume that their suits stayed at 100°
F. Looking back to the Temperature Conversion chart we see that this temperature is 311°
Kelvin which we need to know in order to use the Stefan-Boltzmann radiation equation.
We must invert the original formula to look like this.
I (watts) = K 4 x ( A x e x a)
Thus we find that there are 80 watts being radiated. 8 This must be subtracted from the
571 total watts, which leaves us with 491 watts. 9 To round out the numbers we add 9 watts
for radios, pump heat, etc. for a total of 500 watts. I0 Since there are 860 calories per watt
and, assuming we can work at 100% efficiency we must make enough ice to carry off 430,000
calories per hour. " In 4 hours that adds up to 1,720,000 calories. 12
To lower the temperature of one gram of water one degree C requires the loss of one
calorie of heat. Upon the formation of ice, a gram of water loses 80 calories. Therefore a
temperature drop from 100° F (38° C) down to freezing (0° C) entails the transfer of 38
calories, and when that gram freezes it absorbs another 80 calories for a total of 118 calories
per gram vented out the blowhole. If we divide that 1,720,000 calories by 118 we get 14,576
gms of water that we must eject. 13 This is 14.6 liters, which equals .514 cubic feet. 14 That
would take up 1/4 of the PLSS's volume. 15 The weight of this is 32 pounds on Earth, which
is or 38 % of the total claimed weight. 16
So let's take off the kid-skin gloves and get realistic. Using an efficiency of 40 %, which
is still high compared to most mechanisms, and a suit temperature of 80° F, we find that
23.78 liters of throw away water is needed. This is 52.3 pounds on Earth, 62 % of the
PLSS's total weight and .839 cubic feet which is 40 % of the unit's volume. Remember that
the pack also holds an oxygen bottle, a carbon dioxide scrubber, a dehumidifier, a water
bladder for the cooling circuit, dump water bladder for ejection, a heat exchanger, a radio
that monitors bodily function, a communications radio with power enough to reach Houston.
And it also contains a battery large enough to power everything listed above. Can you
fault me for feeling that these packs were designed and fabricated by the Wizard of Oz
If we divide the 23,788 gms of water by 240-minutes we get 100 grams a minute being
spewed out the blow hole. At an efficiency of 40 %, 60 grams a minute of frozen vapor
would escape the heat exchanger, making quite a whoosh as it ejected. Did anyone hear the
astronauts make any whale jokes about their blow holes When the other guy's suit vented,
did any body ever shout "Thar she blows!" Or is it that any type of venting simply not done
in public
Much more realistically our space heroes should have pranced about carrying a Robinson
Crusoe parasol. Blocking direct solar radiation would have alleviated most of the heat
absorption problem, at least while they were walking on the Moon. However, not only
would it have affected their macho image by carrying a Mary Poppins umbrella, it would
have been a severe impediment as they went gamboling about. Also, it might have pointed a
hot finger at the naked LEM sitting in the broiling Sun without any type of shade. That's
NASA MOONED AMERICA! / Rene