EVs are impractical. Charging fast can't be done and the network won't exist until the cars get built anyway. But noone would buy them without the network so its impossible.
Oh, you built EVs, 100KW+ chargers and the network yourself? Well, obviously that was inevitable if we had just given General Motors and Ford enough time.
Its not a falsifiable position, so its interesting to think about too.
I think a HUGE force for innovation in silicon valley was simply the graph of moores law.
The practical and financial considerations had a "common knowledge" roadmap to reduce risk and people would race to keep up instead of plod along.
Getting starship to work reliably still involves some never done before procedures that remain to be proven. But SpaceX has a plan that might work, if it doesn't there are many ways to adjust the plan. With enough time and money, they can do it.
Colonizing mars is not so easy to show as feasible. Certainly we can launch a bunch of cans and digging equipment and get a few people living there. But anything like a self sustaining population? Don't know, we don't really have a concrete plan of how to do that. People often say, if you think you can colonize mars, colonize the Gobi Desert first, as it is 10,000 times easier.
Most importantly, colonising the moon is tractable in terms of emergencies: if someone on the moon suffers an accident and needs a surgery, they could be in a hospital on Earth in a day or two. If their shelter is damaged, or supplies are needed, we can send help to the Moon and have it arrrive before everyone is dead.
You are on mars and suddenly are suffering from liver disease? You are probably dead. It's going to be like the life of iur first Abtarctic explorers, when they get in trouble, there is no help. Many don't return, and noone stays there to live. To this day noone 'colonised' Antarctica.
Mars settlement is only viable when we have a spaceship factory on the moon, nuclear engines, and we could send the equivant of a large marine research vessel to mars, so 10,000 tons usefull payload, every month.
1. No atmosphere means no weathering, so all of the moon dust is incredibly sharp and easily coats equipment when it gets kicked up. This dust quickly wears out joints and contact surfaces.
2. The Moon's low gravity and lack of atmosphere mean that you have to carry extra propellant to land.
3. Lack of easily extractable resources. It is comparatively easier to extract water and CO2 on Mars to generate methane for a return trip. A trip to the moon requires carrying all of the fuel for a return trip as well.
Nuclear-powered ships built in orbit would drop transit times significantly but I wonder if they'd significantly reduce Mars <-> Earth costs (you'd still need Starships to shuttle payloads through the atmosphere). They are probably required for mining the asteroid belt though...
Lack of atmosphere I get, but how does low gravity require more propellant to land?
(edit: maybe you meant lack of atmosphere due to low gravity, and I got the other meaning contrary to your intent)
However, it is a bit problematic that landing a rocket on the lunar surface can kick rocks around the planet (thanks to the low gravity), possibly into orbit or beyond (which could pelt other equipment). So you need to switch to an entirely different propulsion system for descent, which carries a payload penalty.
https://upload.wikimedia.org/wikipedia/commons/9/93/Solar_sy...
Also there is some water on the moon so you can make rocket fuel, though how much exactly remains an open question
Questionable.
> but it's so thin you still have to land propulsively using rockets
You have to do the same on earth. Starship sized vehicles have to land on earth propulsively too.
Sure, you can do somewhat larger payloads to Orbit without engines but for large things you need to have real engines.
> You definitely need to sacrifice less spacecraft mass to land on the moon
On the moon you can't aerobrake, that is far worse.
> Also there is some water on the moon so you can make rocket fuel, though how much exactly remains an open question
There is a huge difference. Water on the moon has to be mined from permanently shadowed craters. The water is frozen and incredibly hard, its more like mining stone on earth.
On Mars there are places where you can literally land, drill down and make yourself an underground lake pretty easily. Or land basically right on an ice sheet.
On the moon you need to figure out how to get energy down into the crater, you need sophisticated mining equipment, all that equipment needs to handle incredibly low temperatures.
Mars comparatively is not so far away from earth in terms of temperature for your equipment.
In summation, in-situ for rocket fuel/water is far, far easier on Mars.
Ice is 0.5 Mpa stong in the freezer and 2 Mpa at absolute zero.
Thats tensile strenght of chalk and limestone - you can get that with a shovel. Tensile strength of rock is measured in Hundreds of MPA.
The smallest, wimpiest digger you can find can handle it.
So you need to create excavator that operate inside a creator that can operate at extrem temperatures.
On Mars you can literally do what we already do at the South Pole, drill a hole and make it warm.
Its multiple orders of magnitude easier.
https://everydayastronaut.com/raptor-engine/ (scroll down to the text immediately above the RP1/Methane/Hydrogen chart)
Would also provide radiation shielding.
The way I usually picture Mars settlements being made is either finding an existing lava tube and creating an airtight seal on the interior, or digging a hole in the ground, erecting a dome (possibly out of blocks made on-site from local materials), and then burying it in dirt. The dome acts as a compressive structure, and you can inflate a habitat on the inside like blowing up a balloon. Either way, people live underground for the benefit of radiation shielding. And either way, the airtight seal of the habitat has something solid for all that air pressure to press against.
Realistically, though, I wouldn't expect pressure to vary that much with elevation. Mars' weaker gravity implies that it would vary less than on Earth. However, according to this [1], the pressure does vary a lot by season. That's interesting.
> Surface pressure: 6.36 mb at mean radius (variable from 4.0 to 8.7 mb depending on season)
Surface water might not be readily available on Mars, but ice is present on the surface at the poles, and probably elsewhere in shadowy craters or underground. (Unfortunately, the places with the best access to ice are not great for solar power.)
[1] https://nssdc.gsfc.nasa.gov/planetary/factsheet/marsfact.htm...
A space elevator makes no sense on the moon. First of all the orbit is unstable and you would need constant station keeping.
Also, it turns out that if there is no atmosphere you don't actually need an elevator, you can just use electrically driven propulsion without an elevator. You just use a rail gun to shoot stuff into orbit.
> when they get in trouble, there is no help.
But there will be at least one professional doctors and likely a highly advanced medical facility.
> Mars settlement is only viable when we have a spaceship factory on the moon, nuclear engines, and we could send the equivant of a large marine research vessel to mars, so 10,000 tons usefull payload, every month.
You would first need to prove that building such infrastructure on the moon itself isn't far to un-practical and more expensive then going directly from earth.
Common, think about this for just a minute - how many medical staff and how many tons of equipment are required to staff even a small rural hospital? An MRI scanner alone weighs 20 tons. Where are you going to get fresh blood for transfusions, skin grafts, or a kidney transplant? Many medical supplies are perishable and won;t last the trip.
A mobile hospital looks like USNS comfort - 70,000 tons displacement and over 1,000 staff. If you could take it apart and sent it to mars, you would need 700 starships.
That's why, when US army deploys a forward operating base, or arctic explorers set up shop, they can't afford to bring an 'highly advanced medical facility'. They deal with basic injuries and stabilise the patient, and send him back to a proper medical facility asap. You can do that on the moon, but on Mars it takes 6 month to travel once every 2 years.
If you are one of the first people on mars, and your spaceship is not the size of a nuclear aircraft carrier, any kind of non-trivial medical problem is a death sentence.
"You would first need to prove that building such infrastructure on the moon itself isn't far to un-practical and more expensive then going directly from earth."
Look, you can argue that cities in space are too difficult, but if you want to argue that a Moon city is impractical but a Mars city is easy - then I think the burden of proof is on you.
We could reasonably expect any humans going to Mars to bring a lot of medical equipment, supplies, and trained personnel with them. If you need an emergency organ transplant, though, you're probably out of luck.
This isn't substantially different than the risks many people face on Earth, including tens of millions of people in the United States who lack medical insurance. Most people wouldn't accept those kinds of risks voluntarily, but if someone really wants to go to Mars they might decide the risks are acceptable.
If a Mars colony becomes well established with a substantial population, then the risks become less, as the colony would have the infrastructure and full-time expert staff one would expect to find in a typical hospital, and a larger population would mean more potential blood and organ donors.
My point was that you will have at least 1 room dedicated and filled with the best available medical equipment and smart people that have thought about what is most needed. There will be likely two doctors and multiple people trained as backups.
That is only on the first flight, over time, as infrastructure grows the medical facilities will grow as well.
Point being here it is not exactly a crazy proposition for somebody to go on that mission.
> A mobile hospital looks like USNS comfort - 70,000 tons displacement and over 1,000 staff.
You are looking forward way far. If there is need on Mars for that kind of hospital with 1000 staff, 700 Starships is not actually that crazy anymore. Not to mention there are likely lots of optimizations as they serve different functions.
In a typical space elevator, the counterweight end of a space elevator is not in orbit. The center of mass of a space elevator would be above geostationary orbit, so the counterweight would be moving substantially faster than orbital speed at its altitude. A space elevator is held taut by centrifugal "force".
For the Moon it would work a bit different; the Moon doesn't spin fast enough for a purely centrifugal elevator. Instead the elevator would pass through one of the Lagrange points, in effect being held taut between the gravitational pulls of Earth and the Moon.
The Lagrange points aren't stable orbits either, but technically the space elevator would be going through a Lagrange point, not sitting inside that region in orbit. I am not sure how much station keeping would be required. You might still be right overall here.
And for human launch a SSTO reusable lander should be fine.
Once you get regular tourist trips to the lunar surface for the ultra-wealthy, the economies of scale can drive down the cost and grow the market, and you may have the self-sustaining economics for a permanent lunar population to support these visiting tourists – hospitality staff, tour guides, maintenance staff, medical, construction, spacecraft maintenance (vehicles like HLS Starship can't return to Earth for maintenance but that could happen on the surface), etc.
I don't think it has to be either/or, you can do both – establish a crewed research station on the Moon and establish a crewed research station on Mars. But the former has a much shorter path to evolve from a research station (which is dependent on public funding or private philanthropy) into something economically self-sustaining than the later does.
Each Starship is designed to carry 100 tons to mars, IIRC.
What's stopping them from building hundreds of them?
I think the plan is to send a fleet of them with supplies only to mars first, and then bring them back, and do the trip a second time. It's feasible that once the tech is extant and they work and can be produced quickly, that they build hundreds or perhaps a thousand ships.
You can also actually make money from producing telecommunication satellites, startlink sats, etc. and launching them from the moon.
The materials will be clearly far cheaper sourced from earth. You can probably make high quality steel on the moon but its not easy. You need to do prospecting on the moon, find what materials are where. You need to refine those sources into the right materials in the right amount.
You need to put a huge mining, refining, and manufacturing infrastructure on the moon at huge cost. And this is far beyond our current ability in robotics.
And 3D printing object of that size has not proven to be the best solution, there is a reason SpaceX builds Starship the way they build it.
And what does it save you? Why would you do it?
The traditional answer was, because launching from earth is expensive. But that very premise is what SpaceX Starship tries to overcome.
Once you have a fully reusable Starship System, having to launch a few more times should not be that expensive.
The infrastructure you suggest itself would require a fully working Starship system anyway. So why would we build that infrastructure on earth, then build the whole infrastructure again on the moon just so we can launch from the moon.
Additionally, all the other things that we want to send to Mars are on earth, including the humans, food, medical equipment and so on.
This simply doesn't make sense once you really think threw all the requirements end to end. SpaceX actually did think threw these things.
The only actually reasonable suggestion is that you could have some mining for water on the moon and then use a railgun to shoot it into earth orbit. But even the economics of that are very questionable and setting something like that up would likely require a working Starship system too.
Manufacturing on the moon simply makes no sense unless you actually want to create things on the moon. There are cool suggestions for that, see this company (who just got a NASA contract to study this further):
I also don't think it is necessarily easier to manufacture space machines there given the constraints, even if the materials are available. If Starship is fully reusable 100T to orbit for just the cost of the propellant, there is a huge benefit to Earth-based manufacturing in the short to medium term.
Why Mars? 3 reasons: Mars is where the science is, where the challenge is, and where the future is.
Give his full answer a watch, it's very interesting: https://www.youtube.com/watch?v=1S6k2LBJhac
On the other hand the fact that "going for a walk" will be extremely difficult will motivate increased focus on cavern excavation and other construction underground. These are "necessities" on mars but would be "interesting" in the gobi dessert.
Elon Musk doesn't have a concrete plan for a "self-sustaining population". I think all he is actually planning on doing in the medium term is working with NASA to establish a research station with a few dozen people, devoted to research into how to live on Mars. The research station is going to be dependent on continual resupply and funding from Earth.
Growing to the point of being a self-sustaining colony capable of surviving without continual support from Earth is likely to be many centuries away. However, I think Musk is going to want to call it a "colony" from the start, because of the power of aspirational naming, to centre the hope that it will grow into that. But even if it eventually gets there, none of us are going to live to see it. And there's no point trying to even come up with a detailed plan – for a multi-century project, the only possible plan is to make it up as we go along.
What is Elon Musk going to do with his immense wealth when he dies? Don't be surprised if he leaves a massive chunk of it to a charitable foundation devoted to paying for the settlement of Mars. Absent a new Space Race (which may yet happen at some point), governments are unlikely to want to pay for anything more than a few research stations, but ultra-wealthy private benefactors may be willing to pay for a lot more.
If we're talking about population living on earth, that argument makes sense - from a population pressure standpoint , there's no argument to go to mars.
But if we're talking about civilization expanding from more resources, with some space where you can potentially crash land a few asteroids while trying to pull it into orbit for easier mining, then Earth is out of question.
Professor Dave Explains has a nicw YouTube video about it. I can totally imagine that Elin's dynasty will try it.
I have of course read/seen many pie in the sky plans for how to make mars habitable, but they are not concrete plans with even napkin math backing them up.
If you manged to create the atmosphere the radiation on the surface would already be reduced. The extra distance to the sun plus the atmosphere more then makes up for the missing magnetism.
Also, medicine is advancing, if this is actually still the major issue in 30 years is questionable.
But overall I agree, we are not there yet with plans but if we can build a research station there and have constant flights and constantly people living there, space technology will continue to improve and eventually we might reach that level.
You could mitigate these problems by having humans live permanently underground. But that's not exactly terraforming. How can we overcome these significant hurdles to permanent human colonization of Mars?
Oh really?
_The Innovator's Dilemma_, written 20 years ago, includes a chapter based on an industry analysis that said that on current technology trends, mass electric cars would come viable around 2020. Guess what? Around 2020 mass electric cars became viable! Elon Musk figured out that high end electric sports cars could become viable earlier, and built a company around it.
How about those reusable rockets? https://en.wikipedia.org/wiki/Reusable_launch_system documents a history of attempts at making reusable systems literally from the dawn of the Space Age. Everyone knew that in theory it should be possible. The problem was that in practice they didn't work well enough. (For example the Shuttle wound up costing more per "reusable launch" than an expendable rocket would have.) What SpaceX perfected is a vertical suicide burn. It is called a suicide burn because there is no margin of error, and any mistakes /will/ kill you. But it is also the most efficient way to land the rocket. Nobody did it before Musk because nobody was willing to trust their software control system that much. And even still, when humans take a trip on Dragon we /don't/ trust their skills at a suicide burn for the return. We instead parachute into the ocean, just like Alan Shepherd did 60 years ago. (Elon hopes, of course, that Starship will change that.)
So your comment critiquing humanity by critiquing all of the experts who failed to do back of the napkin math showed more about your ignorance than the ignorance of the experts.
Does anyone know if convection is a net positive or negative when smelting metal? I know that one way to remove impurities is to cast a billet and then saw off the bottom and top edge, where the heavy and the light contaminants tend to come out of suspension. But is that a boon or just making the most of a bad situation?
That's a possibility with Mars too, but a riskier return due to the distance.
"As we reported previously (Ronca & Alberts, 2002b), pre- and postflight body weights of dams and the body weights of the offspring used in these experiments were comparable across treatment groups. Within 48-72 hrs following landing, the rat dams that contributed offspring to the postnatal studies gave birth to healthy offspring."
People have feelings. Humanity does not.
But if you're going to give it feelings, a far more likely outcome is that a life-ending meteor will not hit the earth, and that the humanity organism would be much happier if it didn't waste its efforts on chasing a fairy tale, instead of fixing problems here, on Earth.
It boggles the mind that people worry about planet-killing meteors arriving over geological timescales, when the real danger - sustainability - is staring us in the face today, and needs action now.
When we build our own spaceships, we rapidly develop in miniature the sustainable tech needed to really fix earth.
We already have carbon dioxide scrubbers, we just need a vast clean source of energy in order to clean things up, and stop the pollution on net.
Probably fission is a good enough stop gap.
This will happen as soon as the incentive structures are there.
Engineering progress is helping, even if indirectly. Who knows what more energy efficient environment cleansing tech will he developed for spacecraft next. Or power sources, batteries, etc. Technology development is cumulative and crosses over domains.
Spacex is a spearhead rapidly innovating technology. Government mechanisms are a sort of discombobulated rising tide/ pasture of cows, or herd of scared sheep trying to stay on the grazing turf. Assuming gov’s do not get very much more organized, the better the tech, the easier choices the sheep have to make — win wins get things done. We could benefit greatly from tech advances such that gov gets win wins by making green choices. That way the incentives can tilt more favorably more quickly.
The problems of sustainability or climate change are about political will and priorities. They aren't something a single billionaire can solve. Focus on mobilizing, organizing, and educating voters if you want to do something about sustainability.
That's the appeal of dreaming about Mars. It's all vague, hand-wavy, loosey-goosey. It's like a software project, before the first line of code is written. To buy into the vision, you don't need to figure out how it has to work - you just need to have the hope that everything will fall into place, the code will be perfect and defect-free, and it's going to be way better then the system you are re-writing.
The only problem is that billions of people currently depend on the legacy system, and that the vague plan for the re-write calls for it to be carried out blindfolded, with a hand tied behind your back, and to make things more interesting, the language of choice is brainfuck.
If everyone had your attitude there would never be any progress. Imagine if someone told Newton "Why are you bothering with how things fall? Go solve the plague or something."
I have no vision of any Martian society. We can figure that out if we get there. Getting there is the interesting part right now.
Technically you can do it but it's not practical.
It is possible and practical but there's no reason to.
Oh, look here we are. Well, sure anybody could have seen that this was where we would end up - we just didn't agree on when we'd be here.