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Thanks! Fascinating hints at the complexities of working around radiation hazards:

>MCU processor units operate redundantly, receiving and processing identical sensor data to perform the flight-control functions necessary to keep the vehicle flying in the air. At any given time, one of the MCU is active with the other waiting to be hot-swapped in case of a fault.

>Each subsystem has a current monitor to detect possible latch-up current and can be power cycled to clear a SEL. In addition, current limiting is added to prevent a destructive SEL event and most devices are switched off when not in use to minimize their exposure to SEL. For the critical FPGA which is always on for the duration of the mission, the radiation tolerant ProASIC3 is chosen with the military temperature grade (-55 C to 125 C) and -1 speed grade to mitigate the degradation in the propagation delay caused by the total dose radiation.

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I'm always amazed by the crazy crap people deal with in space, and how much protection the Earth affords us. Extreme temperatures, radiation, small bits of material traveling fast enough to go through structural metals like a knife; it's a thrill a second.

Don’t forget vacuum welding

https://en.m.wikipedia.org/wiki/Cold_welding

https://en.m.wikipedia.org/wiki/Vacuum_cementing

The first time it happened it must have been puzzling

This is an important and highly under-appreciated point. We humans evolved under some very particular environmental conditions, ones which are radically different from space in almost every conceivable way.

When people talk about colonizing Mars, I ask them to do the following thought experiment: imagine you are going to move to the Atacama desert. You have to live there for the rest of your life. You get to take one standard twenty-foot shipping container with you. You can pack that container however you like, but you have to live inside the container along with whatever stuff you pack it with for nine months before you can go out for the first time.

Figuring out how to make that work is about 100 times easier than colonizing Mars.

I think that's a poor example.

First off, doing such a moving experiment with only your own funds is a lot harder than if you had billions to millions of dollars to do it.

Secondly, people won't be trapped inside on Mars and will make regular, if not daily trips outside on EVAs (we may need a new acronym as there's no "Vehicle" here.)

Thirdly, a lot of hardware will be outside the "container" including the power generation from nuclear power or solar energy. (Likely nuclear powered sterling engines that have already been demonstrated in subscale versions.) (This contributes to the difference in funds point on my first point.)

Fourth, even though you didn't mention it, I'll add it here to preempt a counter argument. The radiation risks are overstated. Radiation on Mars is at least half that of being in space because you have radiation from one half of the "sky" blocked by the planet itself. Also while the radiation levels are certainly elevated, they're likely not going to kill you. Any long term colonies are going to be mostly underground anyway. (Or more likely simply buried by shoveling dirt on top.)

> doing such a moving experiment with only your own funds

I didn't say that you had to do it with your own funds. But how exactly do you think that extra money would help? Getting to the Altacama desert is not difficult or expensive. That's the reason that the fact that no one has bothered to even attempt it is so damning.

> people won't be trapped inside on Mars

I didn't say they would be. In fact, I specifically said that you would only have to spend nine months (the travel time to Mars) inside the container. After that you can go out as much as you like. You don't even have to wear a space suit.

> a lot of hardware will be outside the "container" including the power generation from nuclear power or solar energy

That's why I gave you a full 20-foot container. But fine, take three containers, which is about what will fit in a Falcon Heavy. Or six. It doesn't really matter. The point is, take some number of containers that you think is a plausible payload for a Mars colony -- and nothing else.

> The radiation risks are overstated

I never claimed otherwise. There are a zillion other things that will get you before the radiation does.

> Radiation on Mars is at least half that of being in space because you have radiation from one half of the "sky" blocked by the planet itself

You have to get there, which exposes you to a lot of radiation. And then you have to live there which exposes you to a lot more, no matter if it is "half" that you would get if Mars was a one-faced world WRT the sun.

Also, how are you going to get these diggers, their fuel, their support systems, etc, etc, to Mars that will excavate holes (lovely to live in) or cover things (ditto)? Why would anyone want to live like that, or worse, condemn their children to do so?

I used (in the 1960/70s) to believe in the colonisation of space. But now not at all - it is simply too difficult. And that's the answer to the Fermi Paradox.

If you at least sleep underground (1-2m), it keeps the total lifetime radiation dose manageable.

For most of the machinery, you would bring the tricky to manufacture bits (tight tolerance mechanical, electronics, non-basic chemicals) with you, and build the bulk structural parts on site. Even for something like a 10,000kg machine tool, only about ~500-2000kgs of materials need to be sent (see granite+epoxy CNC machines[0]). Other machines, such as diggers, they would have to be electric powered. This is not too difficult as most heavy machines are diesel->hydraulic, with electric->hydraulic conversion not too hard (run-time will suffer though).

If you wanted to start a colony, its easy if you can get 10,000 people to go as everyone doesn't have to wear a dozen different hats to keep things going. With current in-use launch tech, its unlikely that enough people can afford to go (or can get a loan to do so). If launch costs get down to ~$500k/ton to Mars, then it would be possible. The biggest issue at first would likely be getting enough electrical power from solar to refine metals and chemicals as that takes a lot of electricity and the likely first sources or raw materials will be sub-optimal as you would be prioritizing ease of access over efficiency.

[0]: https://www.cnccookbook.com/epoxy-granite-cnc-machine-fill/

holes (lovely to live in)

People build hobbit houses and earthships and the like all the time.

https://en.wikipedia.org/wiki/Coober_Pedy

> Why would anyone want to live like that

Think about not being under control of any government of Earth. This is literally a new world, for you to shape. For some people it's worth all the downsides, and more.

Indeed! Instead, you’d get to live under a much smaller, less experienced, and more resource-starved government —- possibly a corporatocracy. Yay!

Control needs a basis from which to operate. I doubt there will be much of one on Mars initially. It would most likely be a direct democracy just because of the reality on the ground.

Instead, you'll have the pleasure of living under what amounts to a ubiquitous-surveillance dictatorship.

What, you think surviving under those conditions will work like a Heinlein novel?

What makes you think Mars would be like that more than Earth? Mars colonists can simply turn the cameras off when they want.

Your sponsors can also just stop supporting you when they want. An uprising on Mars can be struck down by waiting for everyone on mars to die.

Not under control of any government on earth? It's not 2200 yet. Your entire colony will be dependent on earth for the rest of your lifetime. If we had evidence of nitrogen in martian soil and we had already sent machines that increase atmospheric pressure on the planet then you might be justified in thinking that it's just a matter of time. As it is right now you would have to live in an earth sponsored underground shelter and die in there. By defying earth you would just die sooner.

I think the digging aspect is being worked on. I don't think starting the Boring Co. was a random idea. Although the machines don't run on methane. Yet.

Heres what I'm thinking. Since we have money, we test test test to make sure things work. Then each developed nation usa, Russia, china, India, Japan, UAE, Canada, ESA etc with a space program launches 1 a day for a total of 30 days. That would allow 30 shipping containers to arrive within days of each other. The first few are redundant life support/escape/return, the next few allow you to start building, the last few allow you to grow. In the meantime we are building and launching as fast as we can. you have to think ahead by 9 months and have everything planned out as best as you can with redundancy. So scaling, teamwork, redundancy and thinking ahead. Also money, lots of money.

Well, that solution is also perfectly applicable if we were to colonize a desert, or Antarctica, or the ocean floor. Still, all of those are easier than colonizing Mars even if we throw unprecedented amounts of resources at the problem.

Good sequence for a movie, but most likely we will pack a bunch of starships fill of supplies and land them, leaving two available for emergency return, the other N will shuttle more supplies to Mars. We can test the landing and relaunch as many times as necessary using automated systems. By the time humans land they can checkin at the front desk.

I think a base on one of the Mars moons would be nice. You can build a radiation shield and have a nice place to store your stuff. Maybe some fuel could be extracted from the regolith.

My son is an engineer for a company that makes autonomous fork lifts. One month he was at a client at an aluminium smelter with the machines moving hot metal ingots around; the next month he was at a client that had the machines moving pallets of food product food around a warehouse-sized freezer.

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