On Mars you can build shelter with dirt or in caves. You would be better protected than in LEO.
The Moon is very inhospitable, but it's close enough we could have just shuttled an endless stream of ready-to-live habitat modules there, one after another. The tech was there. The will was not.
I'm not saying it would have been rational to do it in the 1970s, but we could have!
On the other hand, what we actually did do (to the Earth) wasn't exactly rational, either.
> On Mars you can build shelter with dirt or in caves.
Really? What machines would be used to build these shelters? How do they get to Mars? How would they be powered? What auxilliary materials will they require and how do those get to Mars?
Launch while also having to launch everything the people we send there need for the rest of their lives, and also launch everything needed to power and maintain that robot for as long as it's required? Hmmmmm...
But okay, let's say we do all that. We can now dig up Mars-dirt. How do we make that into airtight shelter that is also proof against cosmic radiation?
You keep raising these logistical issues like you’re the only person who ever thought of them. And you seem to be underestimating the resources that can be committed. It’s not like people are planning to send one or two rockets and calling it a day. Serious plans involve sending hundreds of rockets every year, and tens of thousands of tons of cargo.
> You keep raising these logistical issues like you’re the only person who ever thought of them.
Better than to hand-wave them wouldn't you agree? Because these issues are real, hard and very limiting factors, and they don't go away by throwing money at them. And I'm pretty sure I am not the only person who keeps raising these issues.
> Serious plans involve sending hundreds of rockets every year
That would be a really neat trick.
Mars's synodic period with Earth is 780 days (about 26 months) and the resulting transfer window lasts a few weeks at most. So if you want to send even 100 rockets per year, you have to start +200 rockets within that launch window.
To put that into perspective, since 1960 there were a grand total of 50 Mars missions, that includes unsuccessful ones, which were more than half: https://en.wikipedia.org/wiki/List_of_missions_to_Mars Most of these missions didn't land anything on Mars, and not a single one involved landing the spaceship itself, or had even remotely the kind of payload capacity that a colonisation effort requires.
So unless someone has a workable idea for a completely new propulsion system, I'm afraid there won't be "hundreds of rockets every year".
Edit: Oh, I almost forgot, small question: How do these "hundreds of rockets per year" get back to Earth? Because, if they don't, well, that's gonna up the launch costs somewhat, wouldn't it?
You could launch 200 rockets the same day if you wanted to. These things are exactly what throwing money at works for. If you have a really deep pipeline of several, the rockets could also be coming home - but cheap transfers take a really long time.
> You could launch 200 rockets the same day if you wanted to.
No, I can launch 200 rockets the same day if I have sufficient rockets, launch pads, reload-capacity on these pads, fuel, and personnel.
We have none of these things, and they cannot be solved by throwing money either. Just one example why not: Launch sites have geographic requirements.
> If you have a really deep pipeline of several, the rockets could also be coming home
A pipeline of what, rockets!?
The fuel-requirements of a spaceship far outstrip it's payload capacity. That's not me saying that, but physics.
So I have to launch M rockets to bring N rockets back home, with M being a multiple of N. And then to bring M home, I have to launch L rockets, with L being a multiple of M. Did anyone say "geometric growth"?
Yes, it does. What is doesn't have: lots of available energy, industrial facilities, storage tanks, or any of the other things required to actually make in-situ methane/LOX production feasible.
You don't have to believe me, the helpful folks at CSS have provided all the numbers and background data:
> Starship uses Methane/LOX because almost all modern rocket engines do
That is simply not true. Starship has been built for Mars and Elon has said it himself that making fuel on mars makes it using methane the only option. It's not some exploratory science craft that can live in the luxury of just importing everything from Earth. It's a relatively very cheap, massive water tower free of NASA's hope-ending bloat that is the only current realistic shot at our species being multi-planetary.
Yes that is true, as shown by the link I provided. Methane/LOX is simply one of the go-to options for liquid fuel rocket engines these days, whether or not these engines are intended to go to Mars or not.
And btw. SpaceX themselves market Startship as a transport vehicle "to carry both crew and cargo to Earth orbit, the Moon, Mars and beyond."https://www.spacex.com/vehicles/starship/
> the only current realistic shot at our species being multi-planetary.
I'm curious: How does building a base on Mars, that is 100% dependent on regular support from Earth to survive, contributes neither resources nor self-sustaining living space to our species, cannot terraform the planet, and cannot serve as a backup in case Earth goes boom, make our species "multi-planetary"?
A multi-planetary species has permanent settlements on more than one planet or moon, that are either self-sustaining, or contributing (resources), or both. These settlements serve a role beyond bragging rights and exploration. A Mars base, insofar as we could currently make it happen, doesn't do that.
If a 15th century nation brought 5 guys to some bare-rock-island in the middle of the Atlantic and left them there with the promise to drop by every now and then to bring them food, that doesn't make them a colonial power.
Other than Mars, the moon is near enough to actually make permanent bases feasible, which could provide a platform for further space exploration (Launching something from 1/6th of earths gravity uses a lot less energy). Luna is near enough to support a colony, including rotating crew, and it actually has a resource that could become useful in the not-so-far future, that could be worth exploiting: https://en.wikipedia.org/wiki/Helium-3#Moon
Wtf is that "argument"? You proved nothing. Methane is the way because of ferrying all the fuel to mars isn't an option, full stop.
> bla bla because we dont have bases on 10 planets/moons we aren't multiplanetary
With the more urgency we should press on then. Humanity has advanced on other fronts enough that it's becoming a real inconsistency/risk because we can die to nuclear, viral reasons due to tech while still being trapped here
> free of NASA's hope-ending bloat
You actually don't know what you are talking about. Please see SLS's budget per launch/kilo VS SpaceX's offerings. NASA was not going to get much of anything done by itself when it comes to not just science, other than scamming money from congress for things that look good but don't work towards realistic human off-world migration
> Moon
This is part of the NASA-specific not hurrying out when your house is on fire strategy. Yes Spaceship will go to moon, but that's far from the main goal because it's not good enough. The mission to go to the moon is literally more of a PR thing funded by that japanese billionaire for SpaceX
It’s more complicated than that. Cargo rockets don’t all need to be launched at once, they just need to be ready to burn in the launch window. In fact because they’ll need to be refuelled in orbit they have to be launched before the launch window anyway. The passenger rockets will be the last to launch.
Optimal transfer orbits have short windows, but there are other orbits available if you’re prepared to wait longer, including ballistic capture orbits, elliptic transfer orbits, and making use of aero braking (skimming through the high atmosphere) for orbital capture.
As for the return journey, it’s unlikely that many of the initial rockets will be coming back. Return journeys will likely be limited to passenger rockets. There won’t be much else to bring back until there is sufficient infrastructure on Mars.
> Cargo rockets don’t all need to be launched at once, they just need to be ready to burn in the launch window.
So what's the plan, launch all those rockets into LEO, and then have them sit there for up to 2 years before sending them on their merry way?
Whos doing maintenance? Who repairs these rockets when they get hit by space debris? Who'd even know one was damaged? What's the backup plan when almost inevitably some of them will fail come travel-day? More rockets? Whos doing maintenance on them, and who pays for them?
Where are all these rockets coming from btw.? Spaceships aint cheap, they have to earn their keep by doing things like ferrying commercial cargo into LEO. Who can afford to have a fleet of them sitting around doing nothing?
Look, I'm not saying that any of this is impossible. I'm just saying that a VERY hard task, that we have never done before, just got an order of magnitude harder. At what point in this hardship am I allowed to wave a little cost-benefit-analysis and ask what exactly we gain from sending people to Mars (aka. nothing that can't be done better with robotic probes)?
> Return journeys will likely be limited to passenger rockets.
Let's start with: return journeys will be limited to rockets that are still operational after landing in a rock-desert, with zero support structures, on a sheet of powdery regolith-dust, and after having been blasted for months with Martian dust-storms, and subjected to extreme temperature differentials.
Humans have 10 successful missions landing robots on Mars, starting in 1975. Robots have been operating on Mars continuously for almost 20 years. Opportunity was active for 15 years. The helicopter Ingenuity has flown 63 separate times and counting. The Perseverance rover is about the size of a hatchback car and carries seven advanced scientific instruments.
Ten years of strong-willed national effort was enough to get us humans landing on the moon. From where we are now, you honestly don't think ten years of strong-willed national (or even international) effort could get us a robot capable of digging holes?
> you honestly don't think ten years of strong-willed national (or even international) effort could get us a robot capable of digging holes?
Yes, I do think that.
Because there is a big difference between an exploratory vehicle that carries a number of scientific instruments and can be powered by a few solar panels or a small nuclear battery...
Just for comparisons sake: Perseverances MMRTG provides 110 watts of power. A single metric horsepower is 735.5 watts. I leave looking up the power requirements of even a small machine that would be capable of digging habitats into the martian bedrock, as an exercise to the reader.
I agree it's not realistic to send a full tunnel boring machine, drilling out 200 to 700 meters per week for subways and highways, to Mars in the next 10 years. Such a thing would have to be assembled on Mars with advanced industry already in place.
I vehemently disagree that we need a 700 meter/week behemoth, sized for heavy rail, to dig out a habitat for one or two dozen humans. I'm imagining something more like a small-ish Roadheader[1], two to four times larger than Perseverance. It would either need to be Diesel powered (yes, shipping the diesel would suck, but it doesn't need to run forever) or we'd need a small solar farm and a couple Tesla batteries powering the thing (we probably want that anyway, for our habitat).
It would take months to dig out a cave large enough for 10 to 20 humans, and there are hundreds of other problems to solve to actually turn a small, potentially unstable Martian cave into a livable habitat. We know the first steps will be slow; that's OK. Besides, we have a decade of engineering to refine the design. Don't underestimate humans.
A (very) small roadheader starts at around 8 metric tonnes, and requires around 20kW of power...just for operating the cutting head. And that's a really small one.
Again, for comparison, Perseverance: 1025kg, 110W of power
> It would either need to be Diesel powered
That would be a neat trick on a planet with an atmospheric pressure of 610 pascals, where oxygen registers barely above a trace element.
> or we'd need a small solar farm
Or maybe a not so small one.
Using Tesla solar panels https://www.tesla.com/solarpanels as a reference point, they produce up to 400W and are just shy of 2m². That's on Earth. Solar irradiance on Mars is 59% of Earths, so these panels will probably produce ~240W apiece. So to meet the energy requirements of even a small roadheader, we need 83 of these panels, each of which is ~21.5kg in mass, so a total of 1.784t in solar panels alone.
Note, that is without cabling, inverters, electronics, spare panels, support structures, etc. ... or the batteries for that matter. Production numbers are also for peak sunlight conditions on Mars, so best-case daylight during the martian summer, and no dust storms.
So depending on how heavy the batteries are, I reckon we are already looking at around 12-14 tons of equipment, just for digging with a single machine. And that doesn't include any prefabricated parts, spare parts, airlocks, other heavy machinery, support beams, other auxilliary materials....
I mean, these roadheaders will require new drill heads every now and then, won't they?
What's the payload capacity of our current space ship designs again? Because...
> It would take months to dig out a cave large enough for 10 to 20 humans,
...we need food and water and medical supplies and power and space suits, and a lot of other things for all these people. Oh, and habitats, because they will need somewhere to live during all these months bevore the cave is ready.
> So depending on how heavy the batteries are, I reckon we are already looking at around 12-14 tons of equipment, just for digging with a single machine.
So you're saying a single Starship could ferry 7 to 8 full rigs? 14 tons of payload is not a big deal right now, much less with 10 years of project-of-national-importance funding. Let's send 2 (one backup) along with lots of other nice goodies for setting up shop then.
> So to meet the energy requirements of even a small roadheader, we need 83 of these panels, each of which is ~21.5kg in mass, so a total of 1.784t in solar panels alone.
> ... I mean, these roadheaders will require new drill heads every now and then, won't they?
1.8t in solar panels and some extra for new drill heads is really not that much tonnage for the kind of project we're talking about. And remember, we're re-using all this electrical infrastructure for our habitat.
> ...we need food and water and medical supplies and power and space suits, and a lot of other things for all these people. Oh, and habitats, because they will need somewhere to live during all these months bevore the cave is ready.
They live on Earth before the cave is ready. Why send them at the same time?
Remember: the original point was that digging a habitat-sized cave on Mars is really not the hard part here, and something we could accomplish within 10 years if we wanted to. 15 to 20 tons of payload and some moderate engineering challenges have not really disproved that notion. Yes, there are plenty of other hard parts.
But we aren't talking about LEO deployment here. We are talking about a flight to Mars. And we won't be deploying that paylod in space, we have to land it, with the ship, with zero support structures on the ground.
> They live on Earth before the cave is ready. Why send them at the same time?
Then please show me the robotic infrastructure that is capable, with no pre-existing support structures, of building a sealed habitat, after self-unloading from a landed spaceship, and self-assembling itself from it's packaged form. All steps have to be done with no human help on site.
Show me that this works here on Earth. And then show me that same thing, but this time, any remote control has a 6-minute delay (and that's still generous, because 3 light minutes is the lowest possible distance between the 2 planets), and it has to be done at in an antarctic dry valley.
So we have a vessel capable of ferrying 100 tons to Mars that's already had 55 seconds of controlled flight from a launch where it was missing 3 engines, developed by a single non-government company. And this is supposed to make me pessimistic about a concerted effort from the United States government being able to make this thing (or something like it) work in the next ten years?
> But we aren't talking about LEO deployment here. We are talking about a flight to Mars.
I was using the payload-to-Mars number, about 100 tons. That does require refueling in orbit. That's expensive, but a pretty simple orbital rendezvous, which we've been doing since 1965.
> And we won't be deploying that paylod in space, we have to land it
Parachutes, aerobraking, skycranes ... these are well-solved problems on Mars. You think we've already hit the limit of mass that's possible to land on Mars?
> Then please show me the robotic infrastructure that is capable, with no pre-existing support structures, of building a sealed habitat, after self-unloading from a landed spaceship
Let's revisit the original point being made:
> Pretty sure we could design and launch a digging robot in 10 years, I dont really buy that as the bottleneck to mars exploration
An extra ~14 tons (half of which we need anyway) and a couple of months of digging is pretty clearly not the bottleneck.
But to actually address your point: the robots don't need to make it move-in-ready, they just need to set up enough that the arriving humans can do it relatively quickly (days). If humans have to IKEA-assemble things and weld* some stuff, that's fine. (*yes, harder on Mars, but possible). Since the spaceship itself will have to be a livable habitat, obviously the hope would be to re-use most of that. We send pre-emptive missions to set things up (dig holes, set up solar panels, gather basic resources), and another manned mission to finalize the hab. Bonus points if we can just scooch the ship into the cave after it lands as the initial hab.
I think we're just deeply divided on what we think ten thousand focused engineers with hundreds of billions of dollars in budget can accomplish in 10 years. Remember, we're talking about a national or international focused initiative here.
> that's already had 55 seconds of controlled flight
Good. And once it makes the trip to Mars and lands successfully, with 100t of payload, then I will accept it as an argument.
> Parachutes, aerobraking, skycranes
We are not talking about a 1025 kg science vehicle here, we are talking about 100t of cargo, that has to land in the same place, preferably intact. Good luck making a parachute that carries that weight in a 610 pascal atmosphere.
And latest the colonists will have to land a ship there, or they are stuck. So no, without ships being able to land on Mars, intact, Mars Colony is not happening.
And btw. since you mentioned Spaceship: I'm pretty sure landing the thing on mars and letting it take off from there, is what it says on their own website: https://www.spacex.com/human-spaceflight/mars/ (scroll down to the "TO MARS AND BACK" diagram)
> they just need to set up enough that the arriving humans can do it relatively quickly (days).
> We send pre-emptive missions to set things up (dig holes, set up solar panels, gather basic resources)
Good, then show me that the robots can do that, under the conditions pointed out above.
> I think we're just deeply divided on what we think ten thousand focused engineers with hundreds of billions of dollars in budget can accomplish in 10 years.
No I don't think we are. I am well aware that nothing about a Mars colony is physically impossible, or outside the reach of contemporary human technology, if we really want to do it. I think it would take somewhat longer than 10 years, given the technological difficulties, but I don't think it is impossible.
The thing where I think we disagree is, given all the problems I pointed out, whether or not it is worth it jumping through all those hoops just for...yeah, for what? For science? We have robots doing that on Mars, and they don't require habitats, or food, or water. Resources? Mars doesn't have any Earth doesn't already have in abundance. Land? The entire planet is an airless, freeze dried, irradiated, toxic wasteland. As a backup plan? Even after a thermonuclear war, Earth would still be more inhabitable than Mars.
Wanna invest the time and effort of 10000 engineers and hundreds of billions of dollars working in international cooperation into space programs? Fine by me! Here are a few suggestions:
- The DART test was a huge success, we should develop that, because defending earth from asteroids could come in handy at some point
- A moon base sounds awesome. btw. the Moon might actually have a valuable resource we don't easily get on Earth: https://en.wikipedia.org/wiki/Helium-3#Moon
- Please build more deep space telescopes
- ISS is getting old
- There is lots of garbage in LEO that we need a solution for
- Eventually we will need much better propulsion systems
All of these activities sound way better to me, than wasting resources trying to set up shop on a worthless ball of dust for no good reason.
I actually think we've basically reached agreement. All your dashed items are higher on my priority list as well, and much more. I want to see Mars terraformed in the next few hundred years, which starts with learning how to terraform Earth (a rather immediate need, in fact!). Sending humans to live on Mars makes terraforming it harder, not easier, since now we can't just chuck ice comets at it without endangering lives. I still firmly believe that we could set up human habitats in 10 years, but I totally agree that we should not.
>> We send pre-emptive missions to set things up (dig holes, set up solar panels, gather basic resources)
> Good, then show me that the robots can do that, under the conditions pointed out above.
For your consideration (I have no idea on the merits of this company, but I see it on this site every once in a while):
> I actually think we've basically reached agreement.
Yes, I do think so too, and thanks for the discussion, I enjoyed it alot!
> I want to see Mars terraformed in the next few hundred years
I think it will be a few centuries until we have the technology to do that, and then carrying out the task will probably take further centuries, but I do think it is a worthwhile goal to work towards.
However, if I were looking for a first terraforming target, I would recommend Venus instead. Reasons being, the planets gravity (which we cannot do anything about barring some serious SciFi-esque breakthroughts in physics) is much closer to Earths (~0.9g), energy may be easier to come by due to it's proximity to the sun, and while its magnetic field is weak, it is still stronger than that on Mars.
> which starts with learning how to terraform Earth
Luckily, that is surprisingly easy. The biosphere is self regulating, so if Humanity manages to pull itself together and stop actively ruining it, it can undo the damage caused so far. Nature will do so anyway, eventually, the question our species has to answer is if we still want to exist by that point or not.
> Good. And once it makes the trip to Mars and lands successfully, with 100t of payload, then I will accept it as an argument.
This guy is trolling. Think if Kennedy said the same about funding the Apollo program only after computers were 50 times smaller and we had solved the F1 vibration problems, among the thousand other ones.
Blinded by wanting to feel right in an argument to the point of proving themselves wrong. It's a bit dark to be on the hopeless side doing that though. Even if it proves hope absolutely prevails here.
> You could totally just dig a 1 meter deep hole with a fancy bulldozer, then plop down a prefabbed house and bury it
Yes, and that "prefabbed house", that is sturdy enough that we can "bury it" under a pile of rock [1] thick enough to provide adequate protection from cosmic radiation, where does that come from? How much mass is that? How is that mass transported to mars? What machines and tools are required to assemble it there, and how much mass are those? How is the energy for these tools provided?
[1]: Just to be clear what a pile we are talking about here: If we used the water-shield method, it would require 5m of water for a 50% reduction in radiation intensity.
Apollo wasn't really fiscally sustainable, particularly given the expansion that you visualize. In 1965 it was 0.75% of GDP per year and NASA was 1% of GDP per year. By comparison the "pork program" SLS is running at 0.018% of GDP so is 40x more affordable. Expanding the Apollo spending in the 1970s probably wouldn't have helped us any when climate change became a concern.
> On Mars you can build shelter with dirt or in caves. You would be better protected than in LEO.
Is that true? Maybe if you never ever go outside but you might as well just dig a very deep cave here on Earth if your entire is to prove that humans can live in extremely inhospitable environments.
The Moon is very inhospitable, but it's close enough we could have just shuttled an endless stream of ready-to-live habitat modules there, one after another. The tech was there. The will was not.
I'm not saying it would have been rational to do it in the 1970s, but we could have!
On the other hand, what we actually did do (to the Earth) wasn't exactly rational, either.