Elon asking for help

[GoSlash27]

34 minutes ago, Beccab said:

What? In what way did they prove that exactly?

Well, you can see it in the free-fall from 10 km up, which is equivalent to Martian atmospheric density at the surface. IIRC, the Angry Astronaut had a video on the subject a few months ago. I'll see if I can dig it up for you.

Best,

-Slashy

[kerbiloid]

1 hour ago, Beccab said:

This is thread at this point is basically no different from:

But was Musk actually asking for help on Venus?

[Beccab]

24 minutes ago, GoSlash27 said:

Well, you can see it in the free-fall from 10 km up, which is equivalent to Martian atmospheric density at the surface. IIRC, the Angry Astronaut had a video on the subject a few months ago. I'll see if I can dig it up for you.

Best,

-Slashy

Angry astronaut has been proved to be one of the least reliable source on Starship and spacex in general, on par with Thunderfoot, getting way too many things wrong to get the "it could be just a mistake" pass. If you link that as your source you may as well link a 4chan forum.
If you can find any reliable source on that I'm all ears

[Rakaydos]

26 minutes ago, GoSlash27 said:

Well, you can see it in the free-fall from 10 km up, which is equivalent to Martian atmospheric density at the surface. IIRC, the Angry Astronaut had a video on the subject a few months ago. I'll see if I can dig it up for you.

Best,

-Slashy

mars pressure is more like 35+ KM up, IIRC. But they did do mars pressure retroburns in the early days of F9 reuse, and that data is still valid. SN20, if it survives entry, will also test upper atmo descent. They already know they can do landing thanks to SN15.

[Rakaydos]

1 hour ago, GoSlash27 said:

Rakaydos,

 The most problematic parts of the "minimize imports ASAP" approach are the increased stakes (a whole lot of humans), the massively increased dependence on a single platform not having a catastrophic failure, and increased pressure of "sunk cost" that comes with going with the full intent to stay rather then visiting to learn *how* to stay. Dude's not going to build an entire city, run into an insurmountable problem, and then just shrug and say "oh, well in that case nevermind". 

JMO,

-Slashy

 

What do you mean by "massively increased dependence on a single platform not having a catastrophic failure"?

Each Starship and each superheavy will have it's own flight history, meaning most flaws can be identified as being vessel specific. The chances for a class-wide failure requiring remedy to affect a synod launch, without getting a waiver for at least resupply, (sunk cost FTW!) is slim, but is also the reason the mars base keeps supplies on hand for a missed synod. The chances of two sequential synods both being obstructed by critical, class wide failures... AFTER successfully getting a significan population to mars, is ridiculusly small. But Falcon Heavy can still throw the most essential supplies to mars if that happens.

"going with the full intent to stay rather then visiting to learn *how* to stay" 

I dont understand the difference. Nothing is going to be perfect on the first go. every problem that arises is a learning experience, one more thing that needs to be mastered for an independant mars city state. Going to stay IS learning how to stay.

You also seem to be positing that there will be some diffictlty that is completely insurmountable, no matter how much mass they can sling to mars. I do not buy your arguments here. Even something as fundamental as gravity can be compensated for with spinning carousels. And building said carousels out of martian iron, makes it that much easier. (carousels are not in the current plan, because they probably wont be needed. But they are an option if they are.)

But hey, if you have a functional fuel plant, which the first crew will set up, you can always bring everyone home packed in like sardines. If you cant get a fuel plant, it's the same problem whether the intent is a city or a research outpost.

[GoSlash27]

Found it!

 

 

21 minutes ago, Rakaydos said:

mars pressure is more like 35+ KM up, IIRC. But they did do mars pressure retroburns in the early days of F9 reuse, and that data is still valid. SN20, if it survives entry, will also test upper atmo descent. They already know they can do landing thanks to SN15.

Yes, on Earth with Earth's atmospheric density and gravity. The problem is that the Mars landing profile requires a much lower terminal velocity than was demonstrated, showing that it will (at least in the current configuration) require either much bigger fins or a lot more DV dedicated to the landing burn than they're planning for.

Best,

-Slashy

[Beccab]

5 minutes ago, GoSlash27 said:

Found it!

 

 

As I said, completely unreliable source. Check the comments of the video you linked, even them make fun of this

Only to quote a few:

Quote

Do more research before worrying so much, you are confusing bleed-off post-terminal velocity with the total deceleration process. No Starship modifications are yet shown to be needed for Mars. The propulsive deceleration on Mars, keeping G forces low, requires only a small amount of extra fuel. The Mars flip maneuver is analyzed at: https://www.academia.edu/44677823/Landing_High_Mass_Payloads_on_Mars Figure 5 should look familiar.

Quote

Someone doesn't know what terminal velocity means...

Quote

There were no issues on the way up. Those were intentional engine shut-downs, one after the other to reduce thrust.

Quote

Isn't the "speed bleed" mostly about going from hypersonic to subsonic though? That wasn't part of the test.

Quote

There have been studies of this, basically there's an optimal altitude/flight path envelope that starship will have to stay in. https://arc.aiaa.org/doi/pdf/10.2514/1.A34262

Quote

"It didn't bleed any speed!" From what?? It slows down from entry speed to a hell of a lot slower as it transitions from space to planetary atmosphere. This test had absolutely nothing to do with that. "It almost got to the pad." Check RGV Aerial Photography. The outline of the entire skirt is clearly visible on the pad.

 

Edited July 13, 2021 by Beccab

[GoSlash27]

9 minutes ago, Rakaydos said:

What do you mean by "massively increased dependence on a single platform not having a catastrophic failure"?

Exactly what you're talking about. While you discount the possibility of such a failure as unlikely, you must acknowledge that it is not zero. In such an event, it's a whole lot less risky to have a couple dozen researchers dependant upon a 'hail mary' desperation mission than several tens of thousands.

 I think we're just not going to see eye to eye on this one. You take the optimistic view, while I'm more risk- averse.

Best,

-Slashy

6 minutes ago, Beccab said:

As I said, completely unreliable source. Check the comments of the video you linked, even them make fun of this

Only to quote a few:

 

Sorry, but none of those links provide any useful rebuttal and the rest are just ad- hominems.

The SpaceX plan expects that terminal free-fall portion to take 3 minutes on Mars, and it was demonstrated to be less than 2 minutes on Earth. That's a problem that SpaceX needs to look into.

Best,

-Slashy

[Rakaydos]

19 minutes ago, GoSlash27 said:

 

The SpaceX plan expects that terminal free-fall portion to take 3 minutes on Mars, and it was demonstrated to be less than 2 minutes on Earth. That's a problem that SpaceX needs to look into.

Best,

-Slashy

What problem? The engines work just fine for 3 minutes, there's no problem for them to look into. 

[Beccab]

27 minutes ago, GoSlash27 said:

Sorry, but none of those links provide any useful rebuttal and the rest are just ad- hominems.

The SpaceX plan expects that terminal free-fall portion to take 3 minutes on Mars, and it was demonstrated to be less than 2 minutes on Earth. That's a problem that SpaceX needs to look into.

Best,

That's not how it works. Don't take Angry Anstronaut's word as gospel, they are absolutely meaningless given that he made absolutely zero calculations in the video.
The comparison you make there is meaningless. It takes 2 minutes from 10 km on earth to sea level with the drag created by starship; without any atmosphere and earth gravity, the same process would have taken sqrt(10,000/9.8)=32 seconds. But there's no place on mars where the atmospherical density of mars is equal to the one at earth sea level, or even at 10 kms of height for that matters, so the two cannot be compared.
The second part of this that is uncomparable is the flight profile. On any starship hop, it is vertically up and down. On mars, it is the exact opposite, that is almost horizontal. There is no horizontal terminal velocity, only vertical, which means the atmosphere is going to bring you as close to zero as possible horizontally.
Third, you talk about free fall. This is not free fall, at all. Going at terminal velocity always means that you *aren't* in free fall, in fact the vomit comet to simulate free fall has to use its engines to compensate for the atmospheric drag.

Again, never take a youtube video as a source. Make your own calculations about what is being talked about, or better yet find a reliable source talking about the problem to see if it actually exists. This one in particular literally cannot exist, the drag created by a particular shape can be throughly verified in computer simulations and doesn't need real testing nowaydays. They were testing the control from the aero surfaces, engine reliability, cold gas thrusters, pressure holding of the tanks etc, but nothing like that. it is clear in the video that Angry Astronaut completely misunderstood the nature of the test

Edited July 13, 2021 by Beccab

[southernplain]

10 hours ago, K^2 said:

US wants to go to Mars, because that's where they wanted to go to during cold war to beat USSR and back then, we didn't know just how crappy Mars' surface is. Not that we cared too much. All you had to do was get boots on the ground, not establish any sort of long term colony. Today, China just wants to go there to compete with US, and that's it. Russia's claims about having a Mars program aren't even credible, and even China's are in way too early of a stage to call it anything concrete. So really, US wants to go to Mars as some sort of cold war vestige and publicity stunt, and that's about it. "Every single national program," is such a huge overstatement here.

The big money national programs, like NASA, ESA, CNSA, and Roscomos, all have significant Mars exploration programs that are enabling human spaceflight to Mars (MOXIE on Perserverance only makes sense in the context of future human missions). NASA and CNSA are both planning to actually send people there. Need I point out that NASA hasn't sent anything to Venus beyond flybys since Magellan in the 1990's (although we will be returning soon).

The point, rather tenuously made and perhaps overstated, is that money and engineering resources are being spent on going to Mars and solving the problems for staying there. Sure it is political flags and footprints nonsense, but national programs and SpaceX are devoting time and money to the problem. The same can not be said for Venus, despite its advantages, which makes Venus a less achievable destination near term. I am in favour of getting humans living on other planets as fast as possible. 

10 hours ago, K^2 said:

And do what with them? Surface structures on Mars aren't suitable for long term habitation. Between radiation and toxicity and abrasiveness of Martian dust, just waiting out for next departure window on Mars is a huge challenge. You have to dig to build anything remotely sustainable for long term habitation. And that's not something you're going to be able to do with a few landers. You need to land an entire infrastructure on Mars before you can make it habitable. There are a few projects that suggest turning Martian dust into printable material to construct mounds over landed habitats, but even that's a huge undertaking.

Contrast this to Venus where a single lander with a balloon and additional inflatable sections can be suitable for long term habitation. Something like Starship would actually work perfectly, as it can survive the re-entry and has enough volume to bring in the inflatables. You'll have to find a way to resupply it, and you'll have to find a way to dock a return vessel to it, but at least you don't have the fundamental problem of people not being able to survive there with minimal equipment.

Yes, we need to land infrastructure on Mars for long term habitation. I am all for building a transportation infrastructure that allows us to put massive quantities of material on the surface of Mars. Just naturally, we will start will short term habitation modules and land the infrastructure needed to make it more permanent. Given Starships capabilities, the initial short term habitation infrastructure need not be actually very small or limited. We could pre-stage hundreds or thousands of tons of stuff per person on the surface before the first humans get there. The only thing that matters is that the down mass keeps coming, that the volume increases with each synod, and that it is relatively affordable to get there.

Earth (regolith?) moving machines are commercially available off the shelf (although I definitely concede they will require extensive modification), it isn't exactly impossible to imagine putting a few on the surface of Mars given the capabilities of Starship. Digging isn't that complicated given our rovers are already doing it on Mars (albeit at a hilariously tiny scale).

No one is designing Venus dirigibles, although perhaps NASA should throw some money at that problem.

10 hours ago, K^2 said:

No. It's a problem for humans, though. A big one. And since we're trying to find a place where people can live long term, picking a place that's better for equipment is hardly the best criterion.

Yeah, it's a lot easier to organize a return trip from Mars. So if you want to just visit it for a few months, just to put a check mark that you've had boots on the ground, by all means. Go to Mars. I mean, honestly, that's all these gov't space programs are trying to do. Get good publicity stunt of having people walk on another planet. But that solves absolutely none of the long term issues.

We need to be able to get to the destination and return from it, so the equipment we have is absolutely relevant for where we go first. Exploration and settlement of the Caribbean proceeded before exploration and settlement of the South Pole for a reason. There are no near-term hardware proposals for a spaceflight architecture that allows Venus descent and return for humans. 

Starship's architecture is being designed to go to Mars. If you want to propose an alternate architecture to go to, and come back from, Venus, well then I am all on board. Then we need to sell it to SpaceX or whoever else has billions of dollars to spend turning metal into reality. But it seems very unlikely that we are going to throw hundreds of Starships to the bottom of the Venusian gravity well with no way to get them and the people on board back out. Mars colonization is never going to be about the loony Mars to stay proposals. Some, maybe most, of the people who go to Mars (especially early on) are going to want to rotate onto and off of Mars.

Competition between national programs, NASA and CNSA, will be good for Mars colonization long term as they look to find the best solutions to the problems of living on Mars. The technological developments needed to go there, even temporarily, and the data collected while we are there, will enable the colonization process long term.

11 hours ago, K^2 said:

Gravity problems can be overcome if you have enough space, and radiation if you have enough shielding. You can't do either with a few landers. You have to build major infrastructure. And then you're still living short miserable lives in cramped underground tunnels, because that's the best you can hope for on Mars. I just don't even see the point.

Yes, we need a huge amount of infrastructure on Mars for long term habitation. We won't start with a million tons of down mass before the humans get there. We will start with short term settlements and build out from there like every other human settlement program on Earth. The Pilgrims didn't show up to a fully built out 21st century Plymouth when they landed, they had to build the entire society bit by bit. The trick is finding suitably motivated settlers who are willing to take on the risks to build the initial settlements. Incidentally, Venus has the same problem. The infrastructure to support human atmosphere is straightforward, but the rest of the human built environment has to be shipped down there as well since there is no surface to build on and no solid materials to use.

You seem fixated on the "short miserable lives." I think it is far too early to say with confidence that future Mars colonists will be miserable. Underground cities aren't exactly unheard of in human history (see Derinkuyu), but permanent floating societies are functionally unheard of. No one has ever lived long term in a dirigible or hot air balloon. Which isn't to say we can't live like that, but I don't think it is exactly fair to say underground at Mars is miserable, but floating at Venus is great given how limited our dataset is.

This is just spit balling, but it seems likely that never seeing solid ground has some psychological toll on humans who have had a million years of evolutionary history on the surface of Earth.

Finally, and I would like to make this point abundantly clear, I do not think this is an either or proposition. Lets colonize both! That is the sci-fi future I would like to live in. 

[GoSlash27]

42 minutes ago, Rakaydos said:

What problem? The engines work just fine for 3 minutes, there's no problem for them to look into. 

Yes they do.... And if they are relying on the engines to soak up the DV instead of the atmosphere, they certainly have that option. It just means a lower payload capacity than they're currently expecting.

 The other option would be to put much larger fins on it. Either way, it's a potential problem with the current design that they're either unaware of or have decided isn't a problem. Pointing these potential problems out is what this thread is supposed to be about... or at least so I thought.

Best,

-Slashy

Edited July 13, 2021 by GoSlash27

[Rakaydos]

5 minutes ago, GoSlash27 said:

Yes they do.... And if they are relying on the engines to soak up the DV instead of the atmosphere, they certainly have that option. It just means a lower payload capacity than they're currently expecting.

 The other option would be to put much larger fins on it. Either way, it's a potential problem with the current design that they're either unaware of or have decided isn't a problem. Pointing these potential problems out is what this thread is supposed to be about... or at least so I thought.

Best,

-Slashy

These things are trivial to calculate. They already have it figured in, guarenteed.

[southernplain]

9 hours ago, SunlitZelkova said:

The thing about Mars is interesting. To add more on to what K^2 said, the reason people got interested in going there in the first place originally was because of the "canals" that were popularized by Percival Lowell in the late 1800s. Then in the early 50s when ICBM development began, space travel became a very serious possibility which numerous entertainment companies took advantage of. Part of the reason Mars is automatically accepted as the next target for space exploration after the Moon is "because Von Braun said so"; Disney's Tomorrowland episodes on space exploration were instrumental in shaping US public perception of space. Likewise I wouldn't be surprised if the interest in Mars in the USSR/Russia comes from early 20th century works of art (like the movie Aelita), and then considering these same people responsible for propaganda then had to create new works during early Space Race, they naturally chose Mars as a dreamy target, as it is what they did before. And it has stuck since then, often quite simply because "they said so" (they dreamed it first and now I like it too), not because of any logic reason.

I definitely understand the history behind why Mars has been targeted for colonization. However, saying there are no logical reasons to go to Mars is not true. It has a very conveniently earthlike day night cycle and it is the only planet with an atmosphere we can land on, to name just a few points.

9 hours ago, SunlitZelkova said:

I don't think the ground is that important. A colony would fly/float, and would likely be so massive it would be hard to tell you were even in the air. To use an Earthly example, despite regularly getting sea-sick on ocean liners or having trouble sleeping on trains, many passengers of German trans-Atlantic rigid airships in the 20s and 30s found no issues travelling and staying multiple nights aboard the airships. And if the gravity is lower anyways, you are likely going to feel uncomfortable to a certain extent. Versus Venus with its Earth like gravity, which coupled with the nature of lighter-than-air-esque flight should not create major comfort issues.

I understand these points, and I won't say you are wrong in raising them. However, Venusian gravity isn't strictly Earthlike, it is about 10% less than Earth. Given that we don't have very much data at all about partial gravity environments it isn't fair to say that Venusian gravity is Earthlike for humans. The answer is that we need more data on partial gravity enviroments.

I think that a solid surface is important insofar as we can land stuff there, use the surface as a staging point, and extract resources from the surface. Every single built environment on Venus needs to be shipped in except for the atmosphere and what we can extract from it. For example, we can mine water ice on Mars (using techniques we perfect at Shackleton crater on the Moon), and bury habitation modules in regolith.

9 hours ago, SunlitZelkova said:

Some other thoughts-

1. No need to worry about Marsquakes destroying or damaging the colony

2. Colonies can crowd around eachother for support, no need to build them far apart as dictated by Mars surface geography, which eliminates the need for Starship SSTO

3. Safety and perhaps mental anxiety for colonists is a huge improvement, if the Mars city suffers a breach it has the potential to explode, the counteraction of such a problem of which would require building the city in segments that can seal off in an emergency. Versus on Venus where while the air will begin to leak, it will do so slowly, and it poses no threat to the colony itself (the outside toxic atmosphere will not mix with the inside fast, and it will not drop altitude quickly). I would feel much more comfortable in a floating Venus balloon-craft than in a lunar or Mars habitat.

4. No need to worry about dust storms interrupting supply of energy through a solar farm.

1. As far as I know, this isn't an insurmountable problem. Mars isn't particularly seismically active. Marsquakes do happen, but from the evidence that we have they are mild compared to earthquakes. INSIGHT was barely able to detect the marsquake it observed.

2. It is not clear why colonies need to be widely separated on Mars, please explain. There is as much surface area on the surface of Mars as there is on all of the land on Earth, but we don't need to have widely separated colonies to start with.

3. This seems quite overstated. Astronauts on the ISS live in a decades old artificial pressure vessel millimeters from literal vacuum and it doesn't seem to impose undue stress on them. Leaks on ISS are easily detected and quite slow, leaving lots of time to react and patch the hole. The same principle applies to Mars if we can suitably engineer the habitation modules.

4. A reasonable point, but not a show stopper. A backup power source, nuclear energy seems quite good for Mars, is definitely needed.

9 hours ago, SunlitZelkova said:

As you said Martian gravity and radiation are some of the biggest problems, and SpaceX has no presented no idea how to solve them- in fact, they haven't even looked into whether Martian gravity is safe or not. This is beyond irresponsible, and not only threatens human lives- it threatens SpaceX's goal itself. This is not to shame SpaceX employees (including Musk)- they likely simply haven't realized it. Mars is cool after all. But they need to take the colony aspect more serious right now, to prevent massive monetary and human losses in the future.

This concern seems a bit exaggerated given that the only thing we can observe from SpaceX is progress on the transportation infrastructure. Starship is a natural starting place because as it stands, no amount of money will let us put someone on the surface of Mars or floating on Venus.

That isn't to say that there is no work being done behind closed doors or that SpaceX can't leverage NASA's expertise, on ECLSS, habitation, human biomedical needs, et. al, when (if?) Starship is fully operational. I doubt that SpaceX is going to throw some humans at Mars and hope to sustain them later. They can do that with hardware because the consequences are low, but I would guess that they will be quite cautious with humans.

Edited July 13, 2021 by southernplain

[king of nowhere]

Some people here are way more expert than I am, but I am sure that at spaceX they are not total morons. They built spaceship to land on Mars, using the belly flop manuever, they will surely have made all the calculations ahead of time to figure out flap size and descent times and everything.

there's still a lot of things that can go wrong with the fine details, and since this is rocket science it just takes a tiny detail to destroy the rocket. But I just refuse to believe that a multibillion space industry that made dozens of successful launches would just make a blunder as stupid as not calculating the flap size with precision. One may as well suggest that they forgot to put in a command pod.

9 hours ago, SunlitZelkova said:

Sadly Venus isn't considered often despite Soviet papers on floating colonies in the early 70s and Geoffrey A. Landis's work on proposals for balloon based exploration. That's not to say Mars is at fault, but "just because they said so" is a poor reason to choose it as a colonization target.

I don't think the ground is that important. A colony would fly/float, and would likely be so massive it would be hard to tell you were even in the air.

 

the problem with the lack of ground is that a colony, to qualify as such, needs to be self-sustaining. which means it must get resources from the environment, because as much aas we can try to send a closed-cycle ecosystem, there will be losses.

What can you get from Venus atmosphere? Some CO2. Some sulfur. Maybe there's enough sulfuric acid in the air for efficient extraction, in which case you can also get hydrogen. But what about everything else? No nitrogen, no phosphorous, sodium, chlorine; all stuff you'd need to grow plants. No iron, silicon, or anything else you can use to make buildings. Those things don't float in the air, so you need to go down on the ground to get them. So you need to make machinery that can survive the 400+ degrees and 90 atmospheres.

 

Granted, if we had those machinery, and we could conceivably reach the surface of venus in a sort of submarine, and extract from there the resources we need, I'd be all for it. But until we have that, Venus is not feasible. Even when we will have that kind of technology, the amount of material we'd need to send to venus to sustain a colony that could extract resources on its own is staggering. On mars, you can get water, iron, silicon, just by digging.

[Beccab]

7 minutes ago, king of nowhere said:

One may as well suggest that they forgot to put in a command pod.

Check yo staging SpaceX, you already forgot to put the parachutes on Starship

[Rakaydos]

11 minutes ago, king of nowhere said:

Some people here are way more expert than I am, but I am sure that at spaceX they are not total morons. They built spaceship to land on Mars, using the belly flop manuever, they will surely have made all the calculations ahead of time to figure out flap size and descent times and everything.

there's still a lot of things that can go wrong with the fine details, and since this is rocket science it just takes a tiny detail to destroy the rocket. But I just refuse to believe that a multibillion space industry that made dozens of successful launches would just make a blunder as stupid as not calculating the flap size with precision. One may as well suggest that they forgot to put in a command pod.

the problem with the lack of ground is that a colony, to qualify as such, needs to be self-sustaining. which means it must get resources from the environment, because as much aas we can try to send a closed-cycle ecosystem, there will be losses.

What can you get from Venus atmosphere? Some CO2. Some sulfur. Maybe there's enough sulfuric acid in the air for efficient extraction, in which case you can also get hydrogen. But what about everything else? No nitrogen, no phosphorous, sodium, chlorine; all stuff you'd need to grow plants. No iron, silicon, or anything else you can use to make buildings. Those things don't float in the air, so you need to go down on the ground to get them. So you need to make machinery that can survive the 400+ degrees and 90 atmospheres.

 

Granted, if we had those machinery, and we could conceivably reach the surface of venus in a sort of submarine, and extract from there the resources we need, I'd be all for it. But until we have that, Venus is not feasible. Even when we will have that kind of technology, the amount of material we'd need to send to venus to sustain a colony that could extract resources on its own is staggering. On mars, you can get water, iron, silicon, just by digging.

The best way to "mine" venus might actually be by asteroid impactor.  you're already set up to process ambient particulates, so drop a dinosaur killer and mine the dirt out of the air.

[kerbiloid]

And then watch the amusing red sunsets all the day long, sometimes with meteor showers.

"From Venus with love."

Edited July 13, 2021 by kerbiloid

[mikegarrison]

1 hour ago, southernplain said:

3. This seems quite overstated. Astronauts on the ISS live in a decades old artificial pressure vessel millimeters from literal vacuum and it doesn't seem to impose undue stress on them. Leaks on ISS are easily detected and quite slow, leaving lots of time to react and patch the hole. The same principle applies to Mars if we can suitably engineer the habitation modules.

Mars isn't the ISS.

ISS:

• Need more air or water? Ship it up.
• Need more food? Ship it up.
• Stuff breaks down? Ship up replacements.
• Something goes wrong that isn't instantly catastrophic? Hop in the capsules and come home.

Mars:

• What you brought is what you have, and getting back home is not easy.

[Beccab]

Not exactly.

1 minute ago, mikegarrison said:

• Need more air or water? Ship it up.
• Need more food? Ship it up.

These are all things that are planned a long time before they are needed. They don't look in the storage and say "NASA, we're out of coffee, send us some more if you want your science", everything is calculated precisely to fit the needs and has launches on schedule half a year before the actual date. This won't change for Mars, everything will be calculated and sent to be able to arrive with enough margin.

4 minutes ago, mikegarrison said:

Stuff breaks down? Ship up replacements.

This is more definitely problematic on Mars, agreed. If something catastrophic happens to the base, you need to survive there for a period between a few months+6 months for travel time and 2 years if mars and earth are on the wrong side of their orbits, although I'm positive that if the payload isn't that big you could go there even in non-perfect launch windows. If you can't do that you have to abort and go back to orbit to start the trip back to Earth, provided the earth return rocket is still working. But if both the ISS and the return capsules broke you'd be screwed as well, so the very last part doesn't change.

9 minutes ago, mikegarrison said:

Something goes wrong that isn't instantly catastrophic? Hop in the capsules and come home.

This would be identical for Mars settlements, just that the return would take 6 months instead of a few hours or a day at most.

[mikegarrison]

28 minutes ago, Beccab said:

This would be identical for Mars settlements, just that the return would take 6 months instead of a few hours or a day at most.

Only is the ship is ready to go at all times. And then only if they happen to be in a transfer window. If you want to be able to get home at any time, you need a LOT more delta-v, and it's still going to take months and months.

For example -- medical emergency? Emergency surgery needed? Handle it there or somebody dies. Like in Antarctica in the winter, when doctors have had to do things like the guy who had to remove his own appendix.

Edited July 13, 2021 by mikegarrison

[Beccab]

2 minutes ago, mikegarrison said:

For example -- medical emergency? Emergency surgery needed? Handle it there or somebody dies. Like in Antarctica in the winter, when doctors have had to do things like the guy who had to remove his own appendix.

Starship is actually known to be planned to have proper medical system on it https://boards.greenhouse.io/spacex/jobs/5305733002?gh_jid=5305733002

[mikegarrison]

4 minutes ago, Beccab said:

Starship is actually known to be planned to have proper medical system on it https://boards.greenhouse.io/spacex/jobs/5305733002?gh_jid=5305733002

Starship is known to be the TARDIS. It can fit an infinite amount of stuff and also 100 people into a volume that is smaller than what 6-ish people live in at the ISS.

Edited July 13, 2021 by mikegarrison

[king of nowhere]

2 hours ago, Rakaydos said:

The best way to "mine" venus might actually be by asteroid impactor.  you're already set up to process ambient particulates, so drop a dinosaur killer and mine the dirt out of the air.

What could possibly go wrong?

[Beccab]

9 minutes ago, mikegarrison said:

100 people into a volume that is smaller than what 6-ish people live in at the ISS.

That's possible the least meaningful comparison that can be done. Orion is going to store 4-6 people for deep space missions on a volume that is less than 40 times smaller than starship.

I'm not saying it will end up with 100 people on it, but the ISS has nothing to do with the reasons