Primarily for general aviation discussion, but other aviation topics are also welcome.
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By Dave W
#1842169
I think that's about 3.5 litres of oxygen, so equates to about 16.7 litres of Earth air.

This says that yer average human consumes about 550 litres (equivalent) of pure oxygen a day, so 23 litres an hour or 0.38 litres a minute.

So that's not far off. It doesn't seem much, does it?
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By Miscellaneous
#1842172
Dave W wrote:It doesn't seem much, does it?

Not if you are using the hot air often expressed on the forum, as your yardstick? :wink:

To tell you the truth I am struggling to get my head around the magnitude of much of this achievement. It struck me today that determining the atmosphere and gravity on Mars sufficiently accurately that the design from the equations resulted in flight is a monumental achievement in itself. :shock: Simply marvellous. :thumright:

I'm with @Paul_Sengupta, the thought of what has to come that we will never see is a bit of a niggle. I doubt Galileo gave much thought to missing the first flight on Mars after he died. :wink:
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By akg1486
#1842173
Colonel Panic wrote:I was surprised to read that 5 grams of oxygen would be enough to keep an astronaut (on Mars) breathing for 10 minutes. Seems a very small number to me!

A quick calculation (which may be wrong) says that 5 grams of oxygen is what you'll find in 110-115 liters of air on earth at sea level. It does sound like very little: if you'd be locked up in a room with 110 liters of air you would suffocate fairly quickly. But that's a lot to do with all the CO2 you expel. In a space situation you could probably make use of all the oxygen in the air.

Another way of calculating oxygen need would be to convert the energi needed per day (some 2 000 kcal) to the weight of the stuff being metabolized: fat and carbs, mostly. And then calculate how much oxygen is needed to burn that under ideal circumstances. My high school chemistry from forty years ago isn't enough for a quantative calculcation, but I can give it a go from a qualitative point-of-view:

Since the waste product CO2 contains 57% oxygen by weight, five grams of oxygen could not possibly metabolize more than 3-4 grams of carbon. And that's not even taking the H2O (89% oxygen by weight) into consideration; there's a lot of hydrogen in both carbs and fat. So let's say five grams of oxygen lets you metabolize 2 grams of food. There are 6*24=144 ten minute periods per 24 hours, so let's say 300 grams of food per day. To get to the 2 000 kcal per day in 300 grams of food, the food must contain some 667 kcal/100 grams. There are food stuffs that reach such level: hazelnuts and chicken fat, for example.

To survive on 5 grams of oxygen per ten minutes, you really need to have special diet and some clever means to use every single oxygen molecule. But the rough figures aren't off by an order of magnitude.

I would be happy if someone more knowledable would give it a go with an estimate!
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By akg1486
#1843762
Miscellaneous wrote:
Mike Tango wrote:Flight four from Wright Brothers Field...

A unique entry for the pilot's logbook! :D

It would have been, but there isn't really a "pilot". There's not even a drone pilot. All the praise goes to the middle-manager to tells the drone to fly. :D
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By akg1486
#1843827
Mike Tango wrote:
akg1486 wrote:It would have been, but there isn't really a "pilot". There's not even a drone pilot. All the praise goes to the middle-manager to tells the drone to fly. :D


Best not tell Captain Grip :D

Pilot Logs First Flight on Another World

Ah: a Norwegian. They are such show-offs! :D
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