Air locks

tahanson43206 · 2025-02-03 08:24:29

Louis created this topic, and I note that in 2017, JoshNH4H described the habitat atmosphere in terms that match up reasonably well with the consensus that has emerged since then. The consensus boils down to the 3-5-8 rule, that every Mars child must learn from the earliest possible age.

I looked for a topic with the words "air" and 'lock" because in early 2025, Calliban reminded us of the practical solution for a non-mechanical air lock.

A U shaped reservoir of water could serve as an air lock on Mars. Such an air lock would need an evaporation cap at the surface, and it might need something similar inside the habitat.

There are two advantages that I see for using such an air lock...

First, there is no need to maintain a seal around the door, which would be required on every other air lock on Mars.

Second, the water would automatically collect Mars dust as residents move from outside through the tunnel to the habitat.

Calliban pointed out that Mars suits that travel through the water passage would collect water on the surface, which would evaporate on Mars. Thus, there would be a need to replenish the water in the lock.

Everything has tradeoffs. I expect that only the very wealthy will have air locks of this type.

This topic is probably worth a read from the top.

(th)

Void · 2025-02-03 10:21:22

A Barometric Airlock. I have been into that sort of thing for some time.

Search "Barometric".

I would suggest that you might look at what that could fetch.

If you had a shed on top of a lake which was covered in ice, then you might have a hatch that covers a hole in the ice.
If the shed can be pressurized to lets say 50 mbar of Martian atmosphere, then you could open that hatch and boiling would not be so much of a problem.

If you had a Hoist in the shed above the hatch, you would bring large items in and out of the lake.

https://endmemo.com/chem/vaporpressurewater.php
Actually 23.2977 mbar is enough for 20 deg C water. So, you could probably go down to 12 mbar or so as the maximum pressure the shed would have to hold. That would almost deal with 10 degree C water.

The Shed, would have horizontal doors like a barn, for instance that would need to be capable of holding up to 12 to 24 mbar of pressure. When the shed was pressurized those doors would be closed, and the hatch could be opened in the floor leading into the lake a load could be transferred Lake<>Shed.

Then the hatch could be closed, and the "Barn Doors" could be opened and the loads transferred Mars Surface<>Shed.

While humans in suits could move though this method(s), it would be much more sensible to be more safely and efficiently remotely teleoperating robots from a safe spot at the bottom of the lake for instance.

Ending Pending

Search Barometric: https://newmars.com/forums/search.php?s … d=78699263

Last edited by Void (2025-02-03 10:39:20)

Void · 2025-02-03 12:30:59

You arguments have some merit, but as you have suggested mine might have a place as well: https://newmars.com/forums/viewtopic.ph … 74#p229574
Quote:

tahanson43206
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For Void re #124
Thanks for your reminder that water exists on Mars.
This is a situation where we both can be right.
I stated that only an obscenely wealthy individual could afford to pay for the water that may exist on Mars to fill a lake.
The fact that water exists on Mars does not mean it is affordable to average persons.
On Earth, it is possible to buy a one liter bottle of water for $1.50 at a convenience store. Apparently one liter can be purchased for as little as 50 cents.
On Mars, in 2025, the price of that bottle of water is infinite.
When the first liter of water lands with the first humans to drop in on the planet, that liter will cost about 80 billion dollars, give or take.
After many many decades, and possibly centuries, the price of a liter of water may fall to the equivalent of 50 cents.
I conclude that in this conversation, it is possible for us both to be right.
All we have to do is to select the epoch we are talking about.
(th)

We still don't have the ground truth the extent that I think Dr. Johnson would be comfortable with.

But the ISS already can tightly recycle water. So, a little water would go a long way. The bulk of water will be wanted to make propellants. Nuclear power would be a good choice for the surface of Mars, I think that most people now believe.

We will want large ice bodies for fuel. But for Make-Up water for people:
https://www.extremetech.com/extreme/167 … of%20water.
Quote:

If you heat up a cubic foot of Mars soil, you can harvest around two pints (one liter) of water. According to new data returned by NASA's Curiosity rover, this isn't just a one-off lucky find, either: It seems that most of the dirt on Mars harbors large amounts of water.

If you have electrical power either nuclear or solar, then you could likely get that water sufficiently to make it on Mars.
But of course that may be more trouble than extracting large amounts from an ice body.

If you want to use nuclear reactors, you will want to have radiators. A pond or lake can be such a radiator, and an airlock, and a farm.

A Lake with an inflatable dome over it might be covered in ice. It may not even need to be a transparent dome, just to serve as a vapor barrier and a radiator. With nuclear you may become less dependent on solar.

So, if you want gardens you can have them in chambers under water, or in vaults dug in the rock under a body of water.
Much of the agriculture might be precision fermentation type, so you don't even need lights for it. You just need electricity to crack water into Hydrogen and Oxygen. The Oxygen you can breath or use as propellants. The Hydrogen of course can be used in precision fermentation along with CO2.

If you have a lake with a low pressure dome over it, then you can play with day/night temperature fluctuations. At night frost will move from the ice to the interior surface of the dome. During the day that frost will evaporate as sunlight warms the dome. You can then compress the humid air inside the dome to produce distilled water.

So, you see the whole setup might serve rather well.

Then if you want greenhouses on the surface to grow vegetables you can do that as an independent function.

Much food can be stored indefinitely on Mars using freezing and drying. So, your solar dependent economy could tolerate interruptions like dust storms or winters. But your nuclear process will make sure that you have Oxygen to breath and water to drink, and even food from precision fermentation and mushrooms and stored frozen and dried foodstuffs.

Large amounts of water near Candor Chaos, the size of the Netherlands: https://www.newscientist.com/article/23 … e-equator/

It has to be evaluated how deep that water goes and if it is brine or ice or a combination.

A landing by SpaceX with robots might be able to give information on that.

Ending Pending

Last edited by Void (2025-02-03 12:50:36)

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#51 2025-02-03 08:24:29

Re: Air locks

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