Hopefully they'll send more drones to mars, moon, etc and less rovers. Unless there are technical reasons I'm not aware of, why wouldn't they scout with drones instead of rovers?
The science payload that an aircraft can carry is much smaller compared to a rover. Also due mass restrictions (afaik) copters are solar-powered, while rovers can be rtg powered; this is pretty relevant for cave exploration as it would be pretty catastrophic for a copter to run out of power in a cave where as rover could at least hypothetically find its way back out.
A sphere may be the best shape for enclosing the most amount of space using the least amount of material, but that's no good if most of that space isn't useful. The fact that the upper reaches of a dome are almost all wasted space make them impractical for contexts like this, especially since breathable atmosphere will be at a premium (and imagine having to heat all of it; average Mars surface temperature is approximately the same as deepest Antarctica). Habitats on Mars will be more like submarines (subarenes?): long and narrow cylinders. I also don't think that any sort of sci-fi self-healing material will help here, because the pressure difference between inside and outside will explode your habitat before any self-healing mechanism kicks in (average surface pressure is the same as 45 km above Earth's surface). Exactly as this article suggests, you're better off sticking your subarene in a cave to protect it from storms and meteorites.
Technically though that atmosphere isn't "wasted" its your reserve. Having a big volume of gas has a lot of advantages because it buffers up local emissions and releases - compare low ceiling vs high ceiling in buildings.
Right, but even there you still have the square-cubed law working for you - the larger volume you deal with, the less surface area you lose heat through.
I'm sure it wasn't your intention, but this comment describes perfectly why I find there's nothing appealing about colonizing Mars. Ah yes, that glorious future of humanity, let's go live underground in a tube. Not that I don't understand the intellectual appeal of space faring (smart people doing smart stuff with technology), but I find the picture of humans in space such an impoverished vision of the future.
What do you consider to be an appealing vision of space travel/habitation?
Like if space travel was an electric car and you were an ICE car kind of guy, what would space travel have to be like for you to be like "Okay, that's pretty cool."
As long as you can convince the ICE car kind of guy he's in the upper caste that gets to stay earthbound while the poor are sent to Mars, it's probably not too difficult.
Why would the poor be sent to Mars? Its my impression the discourse is the other way around; the adventurous, people with options, would mindfully choose to leave earth and start anew.
Gravity similar to earth, breathable air. So my body still works fine on this new planet.
Mediterranean climate would be great, but that's negotiable.
I like your analogy with ice cars and electric cars. It perfectly captures the value system that drives space colonizatuon. It's the fetishization of technology. Because it requires advanced technology, therefore, in and of itself, space travel is the right thing to pursue. It's a modernist mindset.
Great video, loved it. Perfect example. Figuring out stuff, doing science, equations, technology stuff, is valuable in and of itself. No word on what is the inherent value of colonizing another planet, why a human would need to be on Mars in the first place.
Going to Mars will eventually end up the same fate as going to the Moon. It's a branding effort, the most expensive carnival ride. We'll do it a few times, some young people with a sense of adventure, middle-aged people bored with their families, old people looking for a last hurrah. And once there, only to live in the most bureaucratic, degraded, dependent way possible. In a true anti-state of freedom.
It's constructive to think about this in contrast to the explorers of the 15th and 16th century. They discovered paradise. Mountains of gold and silver, perfect weather if you were lucky, freedom (frighteningly raw freedom) from their lords in the old country, grass plains carpeted with red meat, streams overflowing with fish, ... Technology was not a value in and of itself in any of these endeavors. Current discourse around going to Mars, technology _is_ the value.
> The fact that the upper reaches of a dome are almost all wasted space...
Not psychologically, it's not. You might say the same about much of the inside volume of a cathedral; useless space! And yet, we make sure they all have it, because we value it.
> because the pressure difference between inside and outside will explode your habitat before any self-healing mechanism kicks
No, it won't. It's (at most) one atmosphere worth of pressure. ~14 psi. A small hole in a tire doesn't immediately burst it, and it's under significantly more pressure.
The Apollo command module environment was 5 psi pure oxygen. This gave the astronauts lungs the same partial pressure of oxygen that earth atmosphere provides. So not even 14 psi difference, but 5 psi. A difference that can be dealt with during a repair. A commercial aircraft cabin while flying at 40,000 ft has about 8 psi of pressure differential
The difference of 1atm between sea level and the void doesn't tend to yield violent explosions and has been survived. It's not remotely going to resemble a diving bell accident or something. A small puncture and large volume will give time to respond before disaster.
There is a problem with hemispherical habitats that is often overlooked. There are two forces at play - air pressure acts up trying to lift the skin of the habitat of the ground. This must be opposed by anchoring the habitat to the ground, the force of which acts downward.
The problem is that the first force scales with the surface area enclosed (or even volume - I'm not sure as I can't find the reference at the moment), while the second one scales with the circumference. So r^2 versus r. This gives a fundamental limit on how big hemispherical habitats can be.
Scales with area, and if it’s small enough that there’s nopressure gradients, it’s just deltaPA. (Or effectively, pa because it’s basicaally a vacuum out there)
The tensile strength of the membrane will also be interesting for larger habitats.
Interesting... do you have any more information on this? My impression from studying this was that that dissolutional karst would probably not last the hundreds of millions or few billions of years kind of timeframe that separates us from when liquid water was prevalent on Mars. However, I'm not sure if that impression is based on good assumptions -- the oldest caves on earth are thought to be about 340 million years old but the processes that act to remove caves on earth are probably far more active than what goes on on Mars, so maybe there are caves on Mars from a wet period that still exist. However, my impression from working with people on mars and moon cave projects is that the community generally thinks that the entrances that have been found are lava tube collapse features, or related to impacts or small-scale tectonism.
> Types of cave entrances identified in the catalog include lava tube skylights, deep fractures, Atypical Pit Craters (APCs), and other void spaces in karst-similar terrains.
The cave candidates that they displayed in the image were all in the Tharsis Montes surrounding the major martian volcanos in the most volcanic region of Mars, so I suspect that those ones are largely lava tubes.
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[ 4.3 ms ] story [ 102 ms ] threadhttps://en.wikipedia.org/wiki/Ingenuity_(helicopter)
Has anyone thought about constructing self healing domes like all those scifi movies and games imply?
(As for air - we just need enough barsooms of oxygen !)
Like if space travel was an electric car and you were an ICE car kind of guy, what would space travel have to be like for you to be like "Okay, that's pretty cool."
Mediterranean climate would be great, but that's negotiable.
I like your analogy with ice cars and electric cars. It perfectly captures the value system that drives space colonizatuon. It's the fetishization of technology. Because it requires advanced technology, therefore, in and of itself, space travel is the right thing to pursue. It's a modernist mindset.
Going to Mars will eventually end up the same fate as going to the Moon. It's a branding effort, the most expensive carnival ride. We'll do it a few times, some young people with a sense of adventure, middle-aged people bored with their families, old people looking for a last hurrah. And once there, only to live in the most bureaucratic, degraded, dependent way possible. In a true anti-state of freedom.
It's constructive to think about this in contrast to the explorers of the 15th and 16th century. They discovered paradise. Mountains of gold and silver, perfect weather if you were lucky, freedom (frighteningly raw freedom) from their lords in the old country, grass plains carpeted with red meat, streams overflowing with fish, ... Technology was not a value in and of itself in any of these endeavors. Current discourse around going to Mars, technology _is_ the value.
Not psychologically, it's not. You might say the same about much of the inside volume of a cathedral; useless space! And yet, we make sure they all have it, because we value it.
> because the pressure difference between inside and outside will explode your habitat before any self-healing mechanism kicks
No, it won't. It's (at most) one atmosphere worth of pressure. ~14 psi. A small hole in a tire doesn't immediately burst it, and it's under significantly more pressure.
The problem is that the first force scales with the surface area enclosed (or even volume - I'm not sure as I can't find the reference at the moment), while the second one scales with the circumference. So r^2 versus r. This gives a fundamental limit on how big hemispherical habitats can be.
The tensile strength of the membrane will also be interesting for larger habitats.
This, a disproportionate amount of human history has only been preserved in caves.
The lack of radiation shielding is a problem.
The cave candidates that they displayed in the image were all in the Tharsis Montes surrounding the major martian volcanos in the most volcanic region of Mars, so I suspect that those ones are largely lava tubes.
Harder to fly in, though.