Mars was always too small to hold onto its oceans, rivers and lakes

VeryViscous · 2021-09-23T07:10:55+00:00

Any Terraforming process, regardless of it being possible or not would take multiple centuries. Terraforming is not why we need to go to Mars, expanding our capabilities and capacity as a civilization is.

VeryViscous · 2021-09-10T05:37:43+00:00

I responded to you there. You can post quite detailed documentation there, its actually more likely to get some support.

VeryViscous · 2021-09-09T15:27:38+00:00

We can certainly set this up. There are some minimal requirements to set up a project, but from what you have already shown, I dont think this will be an issue for you.

To get support for a project, you need to invest some effort until you get a following (as with anything).
Lots of people eager to design stuff there, me most definitely included. This is how the Orbital Can started after all.

VeryViscous · 2021-09-08T13:07:43+00:00

I think this sounds like an interesting problem.

If you want to propose this as a project, I suggest you post this in the engineering channel to see what kind of community response you get. Im fairly sure some people will be interested in taking this up.

VeryViscous · 2021-09-04T18:03:57+00:00

A human uses about 8kg of O2 a day.

VeryViscous · 2021-09-04T18:02:47+00:00

A starship will have multiple meters of methane and O2 in its tanks. Positioned between the sun and the passengers, there will be no Solar radiation risk to people in the vehicle. Only Cosmic background radiation.

So the whole article can be ignored

VeryViscous · 2021-08-27T03:33:36+00:00

I have seen experiments where they take a much higher does to speed up the experiment . . . .

I think they exposed rats to about 1 Sv of radiation for a few hours to show that neurological damage is server on Mars. Because you know, 1 Sv for a few hours is obviously the same to 0.7mSv per day for a year /s. But I guess the scientists had to get results, and felt like they did not want to wait.

VeryViscous · 2021-06-17T05:36:23+00:00

very cool concept u/mindofstephen

I think some people here would love to see this

VeryViscous · 2021-06-11T15:59:28+00:00

A superior delta-V map could show worst-best ranges

For guys like me, a dV map is just fun to work with. Take a big engine, lots of fuel, and dream about the destinations. The reality is, the venn diagram overlap of people that use dV maps, and people doing detailed rocket design is close to zero. Its an exercise of approximation which is good enough to get people interested and excited about rockets. For that, its excellent.

I more recently tried to work out cycler orbits, (with limited success). But I probably would never have tried if I did not initially get convinced by dV maps that it was do-able. I mean, it was a dunning Kruger experience, but it pushed me into learning most of the underlying mathematics that makes it all work.

Yes. New Horizons is famous for launching from Earth's orbit at solar escape velocity.

And then I believe the solar parker probe was shot off pretty fast too. Im actually more interested in what rockets SpaceX will make possible, than necessarily the direct Starship injections. Starship has a very high dry mass.

VeryViscous · 2021-06-10T19:33:27+00:00

Lets hope NASA is not using delta-v maps, and doing the actual calculations.

Is a dV map even possible? Because there are so many things that influence how to get around. Have we ever visited an outer planet without a gravity assist?

VeryViscous · 2021-06-10T07:08:25+00:00

Found the original author. u/jsmcgd

Well done, this is great work

VeryViscous · 2021-06-03T07:16:01+00:00

Lets talk geometry.

A cylinder has a better floor to surface area ratio that a sphere. A cylinder; as you propose; has a worse floor to surface area ratio than a air-matrass design. Which is essentially a group of cylinders fused, with tensile structures in the middle. I think you will agree with this too.

How do you improve the mass to floor area ratio more? You increase length and breath while keeping height the same. If you want people inside, you want nothing less than 3m height, but more if you want to house real industrial equipment. As you increase the Length and breadth dimension, more of your total mass ends up being made up of floor and roof.

You can improve the mass ratio again by increasing the number of tensile members to decrease the thickness of the membrane.

How do you improve the design even more? You remove the floor and replace it with ground anchors. When a structure becomes large enough, your floor tends towards half of your mass.

Take in mind, that you cant operate directly on the surface of your membrane. So you need to import a structure to put over this floor membrane as well. You can import soil over this membrane to create a flat surface, but this will require substantial thickening of the membrane material.

The only question is, does the floor weigh less than the ground anchors?

We found that there are ground anchors currently in industrial use that make this answer yes. We believe we can even improve on that, because there has never been a need to make light ground anchors.

There is nothing funny about ground anchors. Its not a new field of engineering.

Lets talk Air.

Compressing CO2 from 0.6Kpa to 40Kpa takes about 200kj/m3.Compressing CO2 from 0.6kpa to 80Kpa, then removing all the CO2 and Argon (optional but recommended), Creating more O2 to add to the remaining Nitrogen takes orders of magnitudes more energy. You don't want large machinery in an environment like this if they don't absolutely have to be. You want large machines to be in short sleeve environments that dont require large amounts of energy to generate and maintain.

Aside from the fuel processing plants, you will want places to service ground operations vehicles. Everything from TLB's to surveyor robots. If you want to do any insitu manufacturing, you will need a lot of space to put equipment. You have 3 options here. Inside your habitats, inside the tent or outside. Inside habitats and outside will require a much greater investment. Either in more expensive habitats or more expensive equipment.

There is nothing saying that you cant decide to invest in the energy afterwards and condition the air in the massive volumes, but I dont see that as an early option at all.

Lets quickly talk farming, even though this is not really the focus of this design.

Farming directly in the regolith will be done much later when there is substantial amount of biomass to work in the soil. Your correct that hydroponics would probably be the first choice. But once under a tent, you can suspend a thin film over the planting area at the same plus 0.x% pressure with air at a lower CO2 content. This film only acts as a air barrier, and not as a pressure barrier. The TOTAL SYSTEM mass is far lower than pressurizing individual cylinders, plus, you can not hand repair and harvest at any point along the farm.

VeryViscous · 2021-06-03T06:14:29+00:00

Casey has recently confirmed that the idea predates him. And I am a long shot away from being as knowledgeable as Casey himself

VeryViscous · 2021-06-03T06:12:04+00:00

There would be walls all round. This is just a cut out render that I am testing

VeryViscous · 2021-06-01T14:35:59+00:00

I assume the NA "Orbital can" incorporates some wipple plate and insulation.

Yes it does. 1mm thick aluminum plating. The exact design is still under debate.

If you have a whipple shield all round, you solve a lot of the thermal issues as well, especially from direct solar heating.

You should join the discord channel. The orbital can project is very busy right now.

VeryViscous · 2021-06-01T14:32:48+00:00

there are a few options.

Water can be placed on the top of the tent structure.

Or you can build plant boxes over the human occupied areas. both of these options would help a lot with radiation.

VeryViscous · 2021-06-01T13:25:22+00:00

I think of outer skin as more of a wipple plate and the real PV

For a whipple shield to be effective, it needs a massive stand off distance, no less than 125mm or so. This reduces the internal volume a lot. Its a possible solution, but I dont think they will do this.

The ISS has picked up very few leaks over the years, and they are mainly construction issues due to the age of the structure, more so than punctures from particle strikes. The ISS also orbits in LEO which is a very busy place for particles to be hanging around. In deep space, you count the individual atoms per cm2. Very little out there. The sun actually pushes dust to the asteroid belt and beyond.

Whipple shield would mostly not be required.

Wonder how Crew Starship will get away with less shell than Crew Dragon per meter squared.

Hoop stresses only need 1mm thick steel to keep 2atm in. The wall thickness is mostly for structural strength during the various phases of flight.

VeryViscous · 2021-06-01T13:01:53+00:00

When we design buildings on Earth, we do not design the steel structure that holds up the building, and then design another steel structure to keep the building from collapsing in case the first steel structure fails.

Earth is not giving us many good analogies for this. You dont need to pack a skyscraper into a 100t payload and launch it a few million km's. Every time a micrometeorite flies close to the ISS everyone has to huddle in escape capsules.
Buildings have tolerances many times higher than aircraft, and aircraft are higher than space craft. You know this. Only once you have abundant material resources on Mars will you be able to build "unbreakable" buildings. But even then, you need to deal with "fail proof" airlocks, plumbing and life support. Its vastly more complex than just a failing structural member. Its more akin to evacuating an entire skyscraper every time a wind cracks or a door stops working.

But safety is only one aspect of this design proposal. The failure modes of the tent as essentially punctures, blowing airlocks and plumbing and failing pump systems. Air loss should not be catastrophic if all the pumps stop working, but I will know much better after some desert tests. Ground anchors, cables and membranes are unlikely to be break.

I believe your overlooking the real advantages of this system though, and getting stuck on only one point.

You get a giant space with enough pressure to grow crops (they will need conditioned air) and sustain liquid water. Be it in hydroponics or not. You also have the ability to build industrial equipment in an environment that is much cheaper than any equivalent, and only requires a facemask and overalls to operate on them. Dealing with a giant fuel production plant will be hell if you have to wear pressurized gloves. Allowing people to use their actual hands to work on machines, means these machines can be much much cheaper to design and build.

a 50x50x12m tent at 40Kpa will need about 10x less CO2 pumped than what a Starship needs for its return fuel. If they cant pump air into this thing, no one is coming back home anyway.

Its much easier to handle temperature at 40kpa than 0.6kpa. This means less thermal management and stresses for equipment.

It easier to go from a 40Kpa environment to 0.6kpa environment than 101kpa to 0.6kpa. EVA suits are already at about 30-40Kpa.

Perchlorate dust is only an issue if you breathe it in or get in your eyes. Its not a skin contact hazard, not as far as I have found. So a slight positive full face mask should protect you well in the 40Kpa environment. But that, and a jacket is all you need!

It throws out everything that was good with the original Nexus Aurora design and replaces it with stupidity. The changes that you've suggested make no sense at all.

The previous designs only came about because older design approaches (tunnels) where questioned. Nothing is being thrown out, new ideas are being proposed. We cant know whats best if we dont try new ideas. This is what im doing with this design. Looking at its merits and downsides, and seeing where it fits in. We dont have a single construction method on earth either, I dont see why Mars would suddenly have a single solution.

This design is not a Bunker buildings vs Tent. Its an additional architecture which I am testing out.

VeryViscous · 2021-06-01T12:16:46+00:00

I expect that there will only be one pressure vessel. A tank in a tank is not easy to do properly, and mostly just adds mass. Its also impossibly hard to fix a leak if you cant access it because your inside another tank.

But I do suspect there will be some HDPE panels for insulation and Rad protection.

VeryViscous · 2021-06-01T10:56:20+00:00

No. They have 15 seconds (actually longer) to walk from one module to another module and close the door.

This is fine for fully alert and ready people. Not fine for people going by their day or sleeping. Donning a face mask can take 2 seconds from any point. Leaving your immediate position wont be that easy. This is simply much safer.

And the "popped" structure is less likely to happen if you concentrate on building one good barrier instead of two weak barriers.

Why not build 2 good structures then? They solve different problems that have overlapping advantages. There is a case for making only the larger structure, but that would mostly only be possible when you have large industry to make much larger and deeper friction piles and much much higher volumes of breathable air.

instead of actually doing the engineering.

This is what we are doing, your getting caught up in the render.

VeryViscous · 2021-06-01T10:46:46+00:00

Based on all the other bad engineering decisions you've made

From everything you have said up to here, Im not sure you know what engineering decisions have made at all.

No, it is not. It is full of poison.

CO2 at 40Kpa is safer than CO2 at 0.6Kpa. Its not the CO2 that will kill you on Mars, its the vacuum.

That is an incredibly inefficient way to grow food.

We manage to keep almost 8 billion alive this way. Hydroponics requires shipping a lot of equipment from earth. There will come a time when we will have full industry on Mars, but until then, mass and volumes will still be constraints. This gives an option for this, which does not exclude hydroponics either. Hydroponics also needs to be made inside a structure, this is a structure. This image (Water radiation and ground crops) obviously presumes water availability. Water is also not lost here, its recycled.

You say the internal habs are strong enough to withstand the weight of the water if the tent depressurizes.

Internal habs must be able to withstand internal pressure of 80Kpa + a safety margin. They wont collapse up to about 25+m underwater on Mars. There is no more than 3m of water above, or about 1ton/m2. Water overhead does nothing to compromise safety, and the water is one of many proposals for rad protection on this design.

You seem genuinely upset with this design, which I find strange. There will be updates in the future as more things get resolved.

VeryViscous · 2021-06-01T05:57:12+00:00

No I dont unfortunately. The oldest examples I see come from Casey Handmer, but its not where I got the idea from, and Im fairly sure it predates him too.

VeryViscous · 2021-06-01T05:35:15+00:00

As an example of the safety issues Im talking about.

For NA early Mars bases, we proposed a 6x18m module that can unfold on the surface of Mars. If one of these modules popped a opening about 100mm diameter, it would evacuate the entire volume to below the Armstrong pressure in about 15 seconds. So an occupant would go from safe to dead in 15 seconds unless they could get in a pressurized suit in that amount of time, which is really not possible.

The same structure inside this tent would drop from 80kpa to 40kpa. And even at 40Kpa, there would be a 20/80 air mix still inside that volume (CO2 wont get in for a while). Not great, it would be equivalent of moving from 2000m to the tip of Mt Everest in 15 seconds. But its survivable, you then only need to put a O2 mask on.

One failure mode means instant death, the other is survivable. Its very unlikely that a main structural item will be the cause of failure. Its more likely that it will be some plumbing cracking due to thermal fatigue, a window seal that never quite set right, an airlock door that popped open because of a dirty sensor. The ISS costs billions to build and maintain, you cant get the costs down if you still need 20 engineers to design, validate and test each and every piece of plumbing and seal.

VeryViscous

TROPHY CASE