Landing heavy objects on Mars is not quite as bad as an airless landing, but it still takes a lot of fuel. Von Braun probably would have wanted to build a large space station orbiting Mars, with rockets shuttling back and forth from Earth orbit for supply. Then, with enough fuel accumulated in Mars orbit, a soft landing on rocket power would be possible.
While generating sufficient Methane is probably too big of an ask without involving extensive infrastructure, in methalox rockets (which many next gen rockets are), the larger mass is the LOX (iirc ~75% of propellant mass on Starship is LOX), which is a lot easier to devise automated methods for ISRU. Thus the problem becomes a lot more solvable. You send ahead a system to collect and store LOX, then you bring enough Methane for the return trip, and you also spend the 2 years till the return window collecting LOX.
Although, if you're sending stuff ahead of time and have the expected economics of Starship (ie down from hundreds of millions per ton to the Martian surface to millions per ton), you really can afford to just send ahead enough propellants for at least a round trip.
I remember something similar. The stoichiometric mix is 80% oxygen, but the actual mix is fuel rich, because CH4 is a light molecule, and the end result is a higher specific impulse.
Still, one could imagine that you could run the rocket in oxygen rich mode; you give up some specific impulse, but you might need to carry less CH4 with you for the return trip.
All that said, I just run the numbers, and I had a huge surprise: if I didn't make any mistakes, the Starship has enough fuel for the return trip, without any need for fancy refueling in Mars orbit. According to the wikipedia delta-v map [1], the delta-v needed to go from GST orbit to the Mars transfer orbit is only 1.16 km/s (yes, not a mistake). Then from there to low Mars orbit it's a further 2.1 km/s, but aerobraking is possible. Also out of the 1.16 km/s from Mars transfer to GST, 0.77 km/s can be done with aerobraking on the return trip. But let's be conservative and ignore all the assistance from aerobraking (although the Starship was designed specifically with that in mind). We end up with a total of 3.26 km/s for one way, and 6.52 km/s for both ways.
The exhaust velocity of the Starship is 3.56 km/s [2], which leads to a ratio of delta-v to exhaust velocity of 1.83, the exponential of which is 6.24. So you can have a ratio of initial mass to final mass of 6.24. The ratio of the Starship gross mass to dry mass is 1300/100 = 13, so more than twice the minimum. Of course, the delta-v map assumes the most economical routes, and for human travel you might need to splurge a bit, to get up there faster. Still, 13 vs 6.24 seems like a good margin to me.
[1] https://upload.wikimedia.org/wikipedia/commons/9/93/Solar_sy...
[2] https://en.wikipedia.org/wiki/SpaceX_Starship_(spacecraft)
I still think it would way more feasible to just to find 5-6 guys in the 25-30 year range to send on a one-way expedition. Instead of spending all of their time maintaining a factory making fuel these guys could be spending time exploring the planet and doing experiments. In return humanity would memorialize them and try to send them stuff to stay alive. After a few years we would try to send another crew to join the first crew to make more progress on the planet and build from there.
Some people are accused and convicted of a crime, know they are at fault, and even want to be sentenced for their crime. EG, they knew they were negligent, made a mistake they should not have, etc.
Such types could potentially feel almost relief with such exile, if their personalities aligned with that of an explorer. And if they truly desire censure, punishment, "doing their time" on Mars, instead of rotting in a jail cell, may seem very good to them.
Of course, lots of profiling would need to be done -- but, that is already done for such missions.
But the big bucks are still going into the Senate Launch System.
[1] https://www.nasa.gov/tdm/space-nuclear-propulsion/
[2] https://www.youtube.com/watch?v=nNnsnyIvzps
[3] https://www.bwxt.com/what-we-do/advanced-technologies/space-...
Edit: for my last comment (which I can’t edit now) I meant to say that hydrogen has a high energy content by mass but not by volume. So 1kg of the stuff has a huge amount of energy but also takes up a lot of physical space.
The bigger question in my mind is that in 50 years, will we need to even land humans on mars, or will be able to build space-faring robots where we can upload our consciousness and send that instead.
Humans, or generally all complex life on this planet is well ... adapted to this planet. Space is very hostile to us.
There's a reason why Mars has had six rovers, with opportunity working for 15 years.
Distance to Moon (384,400km) is 0.0017 of that to Mars (225,000,000,000km).
Humans have spent barely a few days moonwalking.
Like in any other business venture this mars/interstellar is a bet, so doubts of success are natural.
Elon Musk, in his 2013 keynote address at SXSW
A few? Over 200 000 payed a scammy company money, to maybe be considered a one way mars colonist.
https://en.m.wikipedia.org/wiki/Mars_One
This year was supposed to be the year they finally go, but surprisingly it did not work out somehow, maybe because the company only knew how to do good looking 3D models and no real hardware. But they did make the proof, that there is no shortage of willing people to make a one way trip.
And in general I am more optimistic, I am pretty sure there will be humans on Mars in the next 50 years. I am not a fan of the guy in general, but I do believe Elon Musk is serious about going there and I can imagine him still dreaming of being the first on Mars (and then build his kingdom there). And the chinese might start a new space race. Then there is India, Brazil, .. lots of ambitions and national pride and egos. Or crowdfunding goes really mainstream and we organize a pure scientific mars mission at some point? 50 years are a long time and the rate of change right is crazy. It does not have to go all in a bad direction. In either way, rocket starts became something very normal. At some point it is just about doing enough of then, for the fuel and supplies. And we can do that. Also robots have come far, who can be send ahead.
What would be the point, though? Besides live streaming someone slowly dying from radiation poisoning?
It’s not like a human can really do anything that a sufficiently complex robot wouldn’t be able to. Also I always assumed that the whole point of going there (or to the moon for that matter) was to show that we can successfully get humans there and back rather than anything else.
But if the point was to start a long-term colony on mars then it would make sense to first send people that would not expect to come back. Robots are cool, but I’m guessing that us humans with our arms and fingers will be able to do general tasks better than robots will for a long while. Humans have ability to fix things, reach things, and to improvise which robots generally lack. Construction or factories on mars will require people on the ground managing those projects.
There would also be a scientific benefit understanding how people age and how long-term social relations can last on mars.
Compared to Earth, Mars has no atmosphere. (100k pascals vs 600 pascals.)
Mars has no magnetic field.
Mars has 1/3rd the gravity of Earth. We know low gravity has deleterious health effects.
Anybody who lived on Mars would have to live inside a pressurized building at all times. Stepping outside would be lethal. If we're able to to build sustainable colonies in these conditions then we might as well focus on colonizing the Moon first. There would be nothing special about Mars, we might as well just live in space habitats. If there is a future of Martian colonization it involves extensive genetic engineering and massive terraforming projects we can only dream of now.
We all watched Star [Trek|Wars] growing up, I get it. Mars is not a viable colonization project. The best you could ever hope for would be, at tremendous expense, an Antarctic-style research station.
This is an area of research that has been explored extensively around earth already. In anticipation of the “real thing”.
Many cultures have a concept of sanctity of the grave, or right of sepulchre. From that point of view, what happens to the Mars habitat where those people died? Does it become a mausoleum forever? Anything else seems very fraught.
It would be a bizarre spectacle to send another trillion-dollar crew whose first task is to clear out the corpses...
We will do whatever we did the last time we explored a new frontier. How many European colonies failed in the new world? What did they do?
Nothing new under the sun.
In at least one case the failure of the colony resulted in the country which founded it being forced into a slightly one-sided merger with its nearest neighbour, which is why the British flag now has blue in it.
Modern nations may be mindful of this and wish to avoid repeating the mistake. On the other hand, they may have a case of the FOMOs after looking at how successful the USA became… at least if they convince themselves their new space colony won't also declare independence just like the USA did.
Considering that colonies on Mars are extremely unlikely to ever be self-sustainable that’s hardly a concern (in fact the opposite might be preferable).
Comparing the US (or any country or place that’s inhabited on Earth, besides maybe Antarctica but even that is not even remotely close) to a potential colony on Mars is beyond absurd.
"The ability to colonise Mars does not currently exist" is true, but tells us next to nothing about what will be possible if we put effort into the attempt, just as the fact that the ability to achieve the goal of "landing a man on the Moon and returning him safely to the Earth" did not exist on May 25, 1961, but the attempt taught us many things including that (and how) we could.
Likewise for colonies, when Columbus set sail everyone knew the world was round, and almost everyone even knew how big it was (except, ironically, Columbus). What nobody knew was that America existed, and if America had not existed then none of the ships that existed at that time could make it all the way to where Columbus thought he was going.
It's the unknowns that hold us back from Mars, but at the moment the only reasons I have to suspect a Mars colony would fail are the black swans, not the problems currently being worked on.
Why don’t you move to Antarctica? We have the technology that would allow use to settle millions of people there. We don’t, because it’s cold, there is nothing to do there and there much nicer places to live further north. In the case for Mars multiply all of that including the cost by (idk) 1000? 10000 times?
> Likewise for colonies
I don’t see the analogy here at all. Yes Columbus took a risk, he did that because he and his investor expected to make a lot of money just like the Portuguese going around Africa did. How is that relevant?
Europeans colonized America because it was green, warm, full of resources and otherwise about as nice as Europe (just with a lot less people due to various reason). OTH nobody colonized Antarctica or the northern half of Greenland etc. due to obvious reasons..
I do however expect that there's enough psychological draw from "the final frontier" to get a million people spending $100k USD for the trip. Can he get that cheap? No idea.
> I don’t see the analogy here at all. Yes Columbus took a risk, he did that because he and his investor expected to make a lot of money just like the Portuguese going around Africa did. How is that relevant?
Because what he was actually aiming for wasn't possible, he just got lucky there was a (just about possible) alternative that he happened to find purely by coincidence.
What I'm expecting, is that we get von Neumann replicators before a Mars colony reaches the current population of Greenland (56k), let alone a million, and also that a lot of people will prefer the Moon instead (the ways in which the Moon is harder are not ones I expect to be important compared to the difficulty of either). But I also expect that some random thing which gets invented specifically as a result of the attempt to colonise Mars to prove really useful in some impossible to predict way.
- Sailing to New England didn’t cost a trillion dollars.
- The expedition wasn’t live-streamed to every pocket back in England.
- People didn’t know what could be found in America. There was a sense of adventure. In contrast, we know what’s on Mars and the answer is basically “nothing”.
History is full of people selling everything and taking a one way trip into a new frontier.
Not a lot. People actually paid to move there because it resulted in a significant improvement in living conditions/income/etc. on average (besides the few earliest attempts). Colonization and exploration was almost entirely driven by profit union at least the 1800s or so.
Colonizing Mars wouldn’t be even remotely comparable in almost any way to what happened in the Americas/Australia/etc.
> selling everything and taking a one way trip into a new frontier.
Yeah, because there was a lot of free land there/natural resources/high demand for labor etc.
To be fair they kind of did. Or rather they never expected to finding anything extremely different to what they have experienced in Europe (besides very low population density and all the benefits resulting from that).
How is that relevant at all? The only thing that comes close to mars are mostly self-sustainable colonies (not a thing) in Antarctica (which is still a more habitable place than Mars by several magnitudes).
> we did the last time we explored a new frontier
Because the cost was relatively extremely low and there were practical reasons to do that?
But I expect that either civilization would be able to resupply them with people or even connect them back eventually, or alternatively (if we do decline) too much stuff would be happening on Earth for people to really notice the fate of Martians.
But then, if we can send automatons that are able to operate a station to such a high degree that they could be trusted to cremate the humans, why send the humans at all...?
> Human history is full of people who have done exactly this.
Are there any self-sustainable colonies in Antarctica (which is more habitable than Mars by at least several magnitudes)? So not humans have never done anything even remotely close to what colonizing Mars would require.
Being the first human to set foot on Mars stands out as one task it couldn't complete.
Something that nobody should be allowed to even try to do in the foreseeable future even id that person managed to get enough resources for that.
Eg. If you scale out to a 10,000 year timeframe and this is step 1 leading to a self-sufficient backup for Earth, then one day some event seriously threatened to take out our home planet, suddenly the ~whole population would feel the expense was worth it whatever the magnitude.
> If you scale out to a 10,000 year timeframe
AFAIK there were no events at last several hundred million years that had a realistic chance of making the Earth less habitable that Mars. So unless we had a ways to cheaply transport millions of people to Mars (maybe space station or the moon would be a better option though?) focusing on building infrastructure that would allow us to minimize the impact of meteorites or massive volcanic eruptions as much as possible.
And in any case if the only purpose of sending humans to Mars is to prove that we can, why go the easiest and most unethical route?
People have said the same of many great endeavours, and it is often hard to predict all everything that results from tackling big challenges.
I suspect that there is likely nothing anyone could suggest would succeed in shifting you position.
Usually due to practical or religious (so practical from the perspective of the people doing them) reasons
> I suspect that there is likely nothing anyone could suggest would succeed in shifting you position.
I’m not sure about that. A rational and well thought out argument might do that.
So all the current Mars-capable rockets are being developed with the idea that there will be return trips every synod.
Maybe those ideas will fail. But there are billions of dollars going toward this goal today, and more in the future. So I would bet very much that a return trip is likely within a decade.
At current levels of technology and investment, colonization won't happen in our lifetimes. I'd wager we'll get, at best, a few very very dangerous and expensive crewed missions and some very basic infrastructure.
Uh, because SpaceX is a serious success?
The last year, they launched 10 times as much payload into space than China.
Musk may be able to eventually manage the latter, but I don't think success at the former is a reliable indicator of that.
And even then, most likely with a layer of indirection that puts Starship in the role of space truck which enables the infrastructure be built, but which isn't the main mode of transport itself: To really make a Mars colony viable, I think both Earth and Mars (for different reasons) would probably want a non-rocket launch system such as an orbital ring, which Starship could help build.
[0] assuming the von Neumann replicators don't eat us all first. He is literally building a bunch of general purpose humanoid robots and suggesting they may take on factory roles… and Tesla/Optimus isn't the only such robot under development.
They also seem to be fairly concentrated on development of new vehicles and don't distract themselves with anything else.
Minimum Viable Product Most Valued Player.
All of his projects have stalled at a middle ground where they are profitable.
Boring Company is actually just Boring. No Hyperloops.
Tesla isnt producing enough cars to really lower the barrier to entry for electrics. Makes a desirable luxury car tho.
Space X has nailed the orbital supply industry, but its space exploration days are still far in the future.
Starlink is an amazing tool for rural areas but has very predictable congestion issues when pointed at urban areas. Planned upgrades will reduce the networks redundancy as he slots in larger middle man nodes. Even then, theres only so much you can do.
Before a musk fanboy comes in here and says he is a futurist a lot of his hard firm dates were years that sounded like "2017".
Middle man nodes? Do you know how satellite Internet works at all?
Every major auto manufacturer is scrambling to build an EV because Tesla left them sitting without any potential market in 5-10 years if they don't. Tesla's goal, stated clearly from the beginning, was to accelerate the adoption of electric vehicles. In this it has definitely succeeded. Yeah, it hasn't moved downmarket as quickly as people hoped. But as long as the more expensive models are being sold faster than produced, that's a capitalism problem not a Tesla problem.
SpaceX launches more commercial payloads than every other launch provider combined. They are investing heavily in next-gen launch capability despite being blocked by lots of red tape for environmental issues tha, a few miles away over the border, nobody cares about.
Starlink - what exactly did you expect here? It was never going to compete with urban FTTH.
Boring company - yeah not sure what you expected either. IMO this is more about having something that can build habitats on Mars. Hyperloop works on Mars without active vacuum systems or airtight sealing.
And no I'm not a fanboy. I think he's very anti-labour for example, which isn't the way to build a stable society. But from a tech standpoint I don't think these are valid criticisms.
There are plenty of people who made more money than him in the dot-com booms and just whittered the money away on building Facebook for Cats or some zero-commercial-application deep tech project nobody will ever hear about.
In the end we wouldn't be talking about him if the Falcon 1 had a single additional failed launch.
What does this even mean? Everyone is only one guy?
https://earthsky.org/astronomy-essentials/close-and-far-mart...
And, no, personally I don’t think Tesla or SpaceX count as giving back.
Why can’t our billionaires at least just slink off to the lovely beaches of some island somewhere. Oh wait, egos…
But Mars? Mars? How does that sound enjoyable? I actually hope he makes it there.
And millions of people? I’m no expert but are there even anywhere near enough launch windows for that? And I’m guessing even just figuring out the cost of the fuel to reach escape velocity would show how this a non-starter for more than Musk himself and a few companions.
> And I’m guessing even just figuring out the cost of the fuel to reach escape velocity would show how this a non-starter for more than Musk himself and a few companions.
You'd definitely be wrong about that. Fuel costs specifically are very obviously fine, the hard parts are (1) "can they make the superheavy/starship combo as reusable as they hope?" (2) "solve in-orbit refuelling", and (3), "kiloton/year Sabatier process ISRU without human supervision or maintenance, growing to megaton/year when humans become available for such tasks".
[0] Which is also why a criticism I see others making, "Musk didn't found Tesla!", isn't a big deal. It's true, but also Tesla had delivered no more than 147 individual cars by the time Tesla took over as CEO.
But that is not actually the order things happened. He was talking about mars colonies before he become the wealthiest on the planet.
> Mars? Mars? How does that sound enjoyable?
Nobody said they want to do it because it is enjoyable. Where are you getting this?
> millions of people? I’m no expert but are there even anywhere near enough launch windows for that?
In what way do you think the number of launch windows constrain the number of colonist?
> I’m guessing even just figuring out the cost of the fuel to reach escape velocity would show how this a non-starter
You are guessing? :)
Yeah, well, that’s just, like, your opinion, man. Say what you will about the tenets of Muskianism but at least it’s an ethos.
> Why can’t our billionaires at least just slink off to the lovely beaches of some island somewhere. Oh wait, egos…
One person’s egotism is another’s genuine belief. I’m personally not surprised someone who had the ambition and luck to be a billionaire would continue doing things they believe in. I’m not even convinced it would be beneficial for them to disappear. What happens to the immense amount of capital they control?
> But Mars? Mars? How does that sound enjoyable? I actually hope he makes it there.
Does he actually want to go to Mars personally? I thought the idea was that he wants humanity to be multi-planetary.
He said "I'd like to die on Mars, just not on impact." in 2013, no idea how serious he is though.
https://finance.yahoo.com/news/elon-musks-vision-die-mars-16....
Right. Sounds cool, maybe they could commission someone to make a scifi tv show but that’s about it.
Why would you want millions of people on Mars? What purpose that would achieve? There is no way this colony could be self sustainable… (also good luck raising the inconceivable high amount of money required to get them there in the first place)
It would literally be the most wasteful and poi thing humans have accomplished (on purpose at least) ever.
Myself I doubt this, there's very few which would affect all of and only Earth. Gamma ray burst? Also Mars. Paperclip optimiser? Probably also Mars. Pandemic? If you're moving stuff between planets, probably also Mars.
Nuclear war and climate change combined won't leave this planet anything like as uninhabitable as Mars, though of course the converse is that the capacity to colonise Mars means the middle of the Sahara, the middle of Antarctica, all superfund cleanup sites, and the top of Mount Everest, all become easy to turn into friendly and pleasant cities you'd be happy to live in.
The amount of ingenuity and co-operation needed to go to Mars may be greater than the amount needed to maintain Earth.
I don't see on Mars is safer than just an orbiting space station. Needing to go to Mars or anywhere other than Earth adds complexity to the issue.
I would (if I had a say in the matter) go for the Moon over Mars or an orbital space station. An orbital space station (or collection of them) for a million people would be very hard, because we don't have a convenient small asteroid to mine for building materials and therefore can't ISRU. I'd pick the Moon because it's close enough that when the inevitable black swan catastrophe happens, it's only a few days travel so we'd have a chance of saving almost everyone's lives if all the water or food was lost to depressurisation/the outside environment/surprise mould.
Mars, to rephrase what I wrote before, is less hospitable than all the worst environmental disasters we can experience on Earth, even if those disasters were combined. Being able to colonise it means we can fix basically anything that goes wrong here.