Modular Mars

[crandles57]

can we see two of these domes with a starship parked in the middle?

Cool concept for an early   / emergency shelter.

You'd want to have a double layer with a bunch of spray in plastic insulation between the layers, both thermal and radiation reduction.

If you're having a double layer, then pump down the space in between to ~true vacuum and use super-insulating MLI. As it is the thin atmosphere on Mars makes MLI much less effective, but with only 1/100th of Earth pressure there's far less force trying to crush a vacuum-insulated jacket.

Doesn't that just change which layer has to be strong and make things marginally worse? I.e. instead of 1atm pressure to 0.01 atm pressure at the outside layer, a 0.99atm pressure difference, you now have 1Atm to 0 difference at the inside layer.

[lamontagne]

https://www.monolithic.org/domes
Something very similar here on earth, they put the concrete on the inside.

Nice site, I like those domes. They'd have to be inverted on Mars, though, due to the low atmospheric pressure, and then somehow anchored to the surface.

To balance the forces, all you need to do is make the footing much smaller than the dome radius. So instead of having a sphere cut in half, it now becomes a mostly-complete sphere "sitting" on a small flat spot.

Picture a radome, but (if anything) the geometry would be even a bit more extreme than what's shown below.

Weve been through this a billion times on here, but I don’t think anchoring is gonna be THAT hard once you have equipment and people on Mars. It’s just intellectually simpler to skip it.

Oh no. Are we back to THIS again? Rohith Dronadula and Haym Benaroya designed a semi-rigid deployable dome with a flat base and worked out the stress for 1 bar of atmosphere with FEA. It's not an unobtanium-level problem.

https://spacesettlementprogress.com/engineering-analysis-of-a-hybrid-lunar-inflatable-structure/

Click through to where the authors kindly provided a link and you can read it for yourself.

@Robotbeat a model of this would make a great 3D printing project if you're feeling bored one day

It works for a small dome, gets expensive for nothing for a larger one.  You can make flat walled pressure vessels, it's just not the most economical choice.  Could be the most practical one in some cases.

BTW, reading the paper, the mass of the baseplate is 192 tonnes, while the mass of the kevlar structure and beams is 25 tonnes, for a total of 217 tonnes.  So the baseplate comes at a really high cost, compared to a sphere.

A mass budget of 50 tonnes would give you a complete sphere, with twice the volume, leaving almost 200 tonnes to fitting out the interior with floors and other useful things such as life support, food and astronauts.  it's a 2021 paper and based on the first design of Starship, with a 250 tonnes payload.

[Twark_Main]

...
Oh no. Are we back to THIS again? Rohith Dronadula and Haym Benaroya designed a semi-rigid deployable dome with a flat base and worked out the stress for 1 bar of atmosphere with FEA. It's not an unobtanium-level problem.

https://spacesettlementprogress.com/engineering-analysis-of-a-hybrid-lunar-inflatable-structure/

It's not that you can't, it's that you're making it heavier and harder for less pressurized volume. Less juice for more squeeze.   

If you're having a double layer, then pump down the space in between to ~true vacuum and use super-insulating MLI. As it is the thin atmosphere on Mars makes MLI much less effective, but with only 1/100th of Earth pressure there's far less force trying to crush a vacuum-insulated jacket.

Doesn't that just change which layer has to be strong and make things marginally worse?

Sure, there's no magic that makes the hab wall not need to hold one atmosphere. Point is you can add vacuum insulation with only a thin layer on the outside.

I.e. instead of 1atm pressure to 0.01 atm pressure at the outside layer, a 0.99atm pressure difference, you now have 1Atm to 0 difference at the inside layer.

Right, so to add vacuum insulation you only needed to add 0.01 atm worth of structural strength on the inside (ie a rounding error, probably not even enough to go up to the next gauge thickness) and 0.01 atm of strength on the outside. Much easier than here on Earth, where you need to add enough strength for 1 atmosphere on each side.

[catdlr]

Ti Morse@ti_morse
First interview with Saurav Shroff (@SauravShroff5), co-founder & CEO of Starpath (@StarpathSpace).

We talk about what it takes to build a self-sustaining city on Mars, creating rocket propellent production plants on the Moon and Mars, and selling solar panels to satellite companies.

0:40 Inputs to create a self-sustaining city on Mars
3:53 Creating rocket propellent production plants
6:21 How much a Nasa rover costs to build
8:02 Building solar panels
15:51 Scaling Starship production
17:56 Why it’s important to make life multi-planetary
24:16 Starting Starpath
26:53 Creating the first 10 Starpath rovers
31:20 Rover testing
33:09 How to simulate Martian soil on Earth
35:11 What if SpaceX didn’t exist
40:14 Keeping fast iteration loops as you scale
49:19 How many Starships it takes to make Mars viable
1:02:43 What are Starpath’s biggest risks
1:11:31 Finding talent that’s aligned with the mission
1:15:30 Living on Mars
1:18:46 Idiot index in the space industry

https://twitter.com/ti_morse/status/1980736116727972120

[InterestedEngineer]

Ti Morse@ti_morse
First interview with Saurav Shroff (@SauravShroff5), co-founder & CEO of Starpath (@StarpathSpace).

We talk about what it takes to build a self-sustaining city on Mars, creating rocket propellent production plants on the Moon and Mars, and selling solar panels to satellite companies.

0:40 Inputs to create a self-sustaining city on Mars
3:53 Creating rocket propellent production plants
6:21 How much a Nasa rover costs to build
8:02 Building solar panels
15:51 Scaling Starship production
17:56 Why it’s important to make life multi-planetary
24:16 Starting Starpath
26:53 Creating the first 10 Starpath rovers
31:20 Rover testing
33:09 How to simulate Martian soil on Earth
35:11 What if SpaceX didn’t exist
40:14 Keeping fast iteration loops as you scale
49:19 How many Starships it takes to make Mars viable
1:02:43 What are Starpath’s biggest risks
1:11:31 Finding talent that’s aligned with the mission
1:15:30 Living on Mars
1:18:46 Idiot index in the space industry

https://twitter.com/ti_morse/status/1980736116727972120

wow.  The leaders of new space are so refreshing in their outlooks and knowledge

[Vultur]

Re pressure: there's probably no reason to have Mars habs at 1 atmosphere. It's additional structural weight for nothing. Even if you don't want to go to higher than 21% oxygen concentration because of fire risk issues, Denver is about 0.82-0.83 atm and Mexico City around 0.75 atm.