Elon asking for help

[mikegarrison]

5 minutes ago, Beccab said:

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

"Deep space" on Orion is a 3-day trip to the moon.

Bottom line is that Starship has been massively oversold as being able to carry 100 people to Mars. There is just no way. But every time anybody mentions this, fans here get all up in arms over it.

If it could take 3-4 people to Mars and back (having pre-positioned fuel and food and supplies etc.) it would be massively successful. Why people insist on defending things like 100 people to Mars  or 1000 people point-to-point is beyond my understanding.

Edited July 13, 2021 by mikegarrison

[Beccab]

2 minutes ago, mikegarrison said:

"Deep space" on Orion is a 3-day trip to the moon.

It's made to support crew for 21 days, not three. Not comparable to a 6 months trip to mars, but it isn't a short time either 

[southernplain]

1 hour ago, mikegarrison said:

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.

You missed the point.  I was addressing the idea that living with the threat of decompression is some unbearable mental strain. 

If we are colonizing Mars or Venus or the Moon or wherever, it is a racing certainty that things will break and people will die. Just our limited forays into space have already resulted in the deaths of 17-19 people (depending on how you count Challenger, Soyuz 1, and Micheal Adams' X-15 flight). The astronauts on Apollo 13 probably should have died from SA-508's pogo event or from the CSM failure, thankfully they didn't.

The possibility that there may be deaths is not a reason to not attempt to go to Mars or Venus or wherever.

However, we can plan and design to account for unexpected failures. We do the same with ISS, there aren't emergency Cargo Dragons or Progresses sitting around in case something happens (AFAIK, let me know if I am wrong). In a time limited emergency, astronauts can abort home, otherwise we know the risks and they are acceptable until the next resupply mission. The same processes can be designed for Mars, with much greater redundancy (enabled by Starship's down mass capabilities). Mars colonists could abort home (early on), abort to another settlement, or sit tight for resupply. Equipment failures can be handled routinely enough given sufficient planning and redundancy.

Quote

 

"Deep space" on Orion is a 3-day trip to the moon.

Bottom line is that Starship has been massively oversold as being able to carry 100 people to Mars. There is just no way. But every time anybody mentions this, fans here get all up in arms over it.

If it could take 3-4 people to Mars and back (having pre-positioned fuel and food and supplies etc.) it would be massively successful. Why people insist on defending things like 100 people to Mars  or 1000 people point-to-point is beyond my understanding.

 

You are right, it is incredibly unlikely Starship ever takes 100 people anywhere. 

However, starship, if it becomes fully operational, can provide us with amazing capabilities that make Mars colonization feasible. 

Edited July 13, 2021 by southernplain

[kerbiloid]

In the best case it won't be bringing every time 20 corpses died from: long-term zero-g with no physiotherapeutic equipment, broken toilet, insufficient power to cool, insufficient power to warm,  insufficient power to breathe, broken water electrolysis plant, and many other things which can't or at least never mentioned to be mounted in the Starship habitat.

[Rakaydos]

1 hour ago, mikegarrison said:

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.

Not all at once, but it does have the habitable volume of Air Force One.

[mikegarrison]

Just now, Rakaydos said:

Not all at once, but it does have the habitable volume of Air Force One.

I wouldn't want to fly Air Force One to Mars.

[Rakaydos]

Just now, mikegarrison said:

I wouldn't want to fly Air Force One to Mars.

How about two air force ones flown near each other, with weekly inter-ship videogame tournaments?

 

The important part is that starship has the volume for a wide variety of services and a dozen people at the same time. And heavy equipment that doesnt get used until you're on mars, gets sent on a cargo flight in the same convoy.

[southernplain]

1 minute ago, mikegarrison said:

I wouldn't want to fly Air Force One to Mars.

If you wanted to fly to Mars, how would you want to get there?

[mikegarrison]

I am well-reconciled that I will never be going to Mars, but I would want something that would dwarf Starship. Of course, we're talking  a whole  different level of investment. Like a global international priority.

[Rakaydos]

3 minutes ago, mikegarrison said:

I am well-reconciled that I will never be going to Mars, but I would want something that would dwarf Starship. Of course, we're talking  a whole  different level of investment. Like a global international priority.

How expensive would it be to build in orbit at 200 dollars per ton?

[southernplain]

3 minutes ago, mikegarrison said:

I am well-reconciled that I will never be going to Mars, but I would want something that would dwarf Starship. Of course, we're talking  a whole  different level of investment. Like a global international priority.

So like a thousand or ten-thousand ton interplanetary freighter? I don't see why we can't make something like that a priority to build if we are serious about Mars colonization. 

Starship is pretty cool, but it is a tiny early modern carrack compared to modern oceangoing cruise liner/cargo carrying behemoths. We are going to need to outgrow Starship if we are serious about planetary colonization.

[GoSlash27]

6 hours ago, Rakaydos said:

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

Ya know... This is not a thread to point out flaws simply to bash on SpaceX, but rather offer concerns and potentially helpful criticism. You are totally correct in pointing that out.

 I wonder if you realize that the only thing less useful to SpaceX's effort than that is posting things like 'they already have it figured in, guaranteed'. Maybe they *don't* already have it figured in, and maybe it's in *their* best interest to check and make sure.

 Tell ya what: How about we just limit the conversation to potential pitfalls, concerns, and potential solutions and agree to not try to convince people who don't work at SpaceX about our opinions?

Fair?

-Slashy

 

 

 

[Rakaydos]

18 minutes ago, GoSlash27 said:

Ya know... This is not a thread to point out flaws simply to bash on SpaceX, but rather offer concerns and potentially helpful criticism. You are totally correct in pointing that out.

 I wonder if you realize that the only thing less useful to SpaceX's effort than that is posting things like 'they already have it figured in, guaranteed'. Maybe they *don't* already have it figured in, and maybe it's in *their* best interest to check and make sure.

 Tell ya what: How about we just limit the conversation to potential pitfalls, concerns, and potential solutions and agree to not try to convince people who don't work at SpaceX about our opinions?

Fair?

-Slashy

 

 

 

This is how your complaint comes off.

[Slyguy3129]

On 7/13/2021 at 2:13 AM, Beccab said:

I am not passionate about him, in fact I couldn't care less about musk. But spacex isn't musk.

There is of course nothing wrong with not following someone or something, it's very normal. But if you don't know something simply say that, don't make stuff up:

There are no hordes with pitch forks going against you, you simply said something incorrect and people are correcting you. It's how life works, nothing wrong with that.

As for spacex, since you were wondering what people like about them:

They are the only company capable of sending up astronauts from the US, which hasn't been possible since 2011. (The only other vehicle for these 10 years was the russian soyuz)

They are the only company landing rockets and reusing them, instead of throwing them in the ocean (or on land, see china)

They already have the most powerful available rocket, the Falcon Heavy

They are building the most powerful rocket in history as I mentioned before, the first rocket fully reusable and that has a lot of uses planned for it (human lunar lander, human mars lander, super heavy unmanned launcher, point to point transportation. Obviously not all will materialise, but these are the planned ones)

They are extremely open about their development and current status of things, you can see about everything they are building re starship in the open in Texas which is unlike almost any space company

Lots and lots of extremely cool videos (not renders) on youtube and the like

I said I don't follow the guy, I said that right off, that meant I didn't know.

Yea, that he does it here in Texas, is my biggest plus in his favor.

Thank you for explaining.

 

[snip]

 

Edited July 14, 2021 by Vanamonde

[GoSlash27]

That's nice and all... but what's it to ya? What, exactly, is your role here? To facilitate potentially helpful advice that SpaceX *specifically requested*, or to complain about how those concerns "come off"?

 If you want to help, I recommend you just sit back and allow SpaceX to decide for themselves which comments are helpful and which aren't.

Best,

-Slashy

 

[K^2]

6 hours ago, southernplain said:

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.

You are showing a lot of evidence for us studying Mars, which makes perfect sense. We can send rovers there and even get sample returns in the future. There is a lot of science to be done on Mars which can tell us a lot about history of Solar system, Earth, and life in general. There is no reason not to sand probes there.

But none of this prepares us for putting boots on the ground, let alone build anything for staying on Mars. Curiosity and Perseverance are large enough to start testing ability to dig and lay foundation on Mars, but these weren't the missions they were tasked with. Absolutely nothing we've sent to Mars actually puts us on the way to a colony.

Everything else is just posturing and PR. Idea of Mars colonies is popular with public. Martian made good bank. NASA is riding on it, so is everyone else. But it's still just science fiction at this point. I seriously don't think you're putting in perspective the amount of infrastructure necessary to survive on Mars more than a few months.

6 hours ago, southernplain said:

Just naturally, we will start will short term habitation modules and land the infrastructure needed to make it more permanent.

You can't progress from one to the other on Mars. You can't just keep landing modules on the surface and assemble them together like in a bad sci-fi movie or a game. To survive long term on Mars, you have to go underground. That means digging out thousands of metric tons of dirt, assembling structures underground, then covering them back up. You need digging machines to do that, which needs their own infrastructure to support, and you'll have to bring thousands of people for short term stay to operate all of that machinery, oversee construction, and possibly do some manual work that the machines aren't specialized for.

Construction of a sustainable colony on Mars is comparable to construction of an aircraft carrier or a nuclear submarine. But underground. In toxic dirt. In near-vacuum. On a different planet. Comparing absolutely everything we have planned for Mars to that effort is like saying that making a model rocket is a serious first step towards orbital launch capability.

6 hours ago, southernplain said:

Earth (regolith?) moving machines are commercially available off the shelf

No. Precisely because dirt and rock are nothing like regolith nor Martian dust. Dust on Mars isn't as abrasive as regolith, but it's exceptionally fine and chemically reactive. It will get into every single joint in machinery, contaminate lubricants, and absolutely wreck any bearings. Not to mention power and cooling requirements. Mars has virtually no atmosphere, so anything that generates any amount of heat is a huge problem. All of the machinery for digging on Mars has to be purpose-built.

Absolutely nothing we build on Earth is usable on Mars. Even electronics are going to be a bit problematic. Though, I suspect, for day-to-day use you'd be able to live with crashes and bugs, similar to how they make do on ISS.

Contrast this to Venus where the only serious problem is corrosive atmosphere, which means you can't have exposed metal structures. But you'll probably want to build out of plastics anyways, and there are plenty of options if all you have to worry about is sulfuric acid. You'll still probably want to custom-build things, but you can at least use off-the-shelf parts like electronics, batteries, motors... An electric rotorcraft built for operations on Earth just needs some protective polymer coating in the motor coils and it can be used on Venus as is. Most crucially here, I think, is the fact that we can test pretty much everything on Earth and not worry that it will behave different on Venus.

7 hours ago, southernplain said:

We need to be able to get to the destination and return from it

You keep saying that. But if your goal is to stay there, ability to stay long term has to be more important than ability to return. Sure, you don't want to fully deny ability to do so, but you don't need to ferry back absolutely everything that's heading to Venus. You just need to have capability to lift crews to orbit.

7 hours ago, southernplain said:

Starship's architecture is being designed to go to Mars.

Which is why it's not considered for absolutely any other purpose. Oh, wait.

Starship is designed for Mars because that's what NASA was throwing money at. The moment they indicated they'd be open to spending on Lunar mission, suddenly Starship is a perfect fit for that as well. But in reality, it's just a convenient reusable rocket. It works great with direct landing on Mars because there is an opportunity to refuel there. Well, in theory. Infrastructure for it is another matter, and money to donuts that idea will get shelved for a LONG while. But that's an aside. You simply wouldn't use Starship for trips to and from Venus atmosphere. You would use a modified Starship or something similar for trips to and from Venusian orbit. It's a perfect craft for doing round trips between orbit of Earth and orbits of Mars OR Venus, and that's by design. It's meant to be versatile. And if you don't need to land, Starship is perfectly capable of bringing enough fuel for a return trip.

That means the rocket you bring to atmosphere of Venus only needs to be capable of bringing colonists from Venus out to an orbital facility for transfer to Starship or another interplanetary vessel. A Falcon 9 delivered to Venus can easily lift half a dozen people out of that gravity well. But in the long term, I imagine we'd switch to an SSTO plane of some kind. It would be parked in orbit where its cryogenic fuels won't cause problems until it is needed. At that point, it can dive into atmosphere, dock with the colony, pick up passengers, and take them to orbit where it would be refueled by one of Starships or w/e.

The turn-around can actually be more efficient than Earth-Mars missions and you wouldn't rely on refueling infrastructure in the short term. Like I said, I expect actual manned Mars missions on Starship to end up being similar, requiring an orbital refueling.

7 hours ago, southernplain said:

The Pilgrims didn't show up to a fully built out 21st century Plymouth when they landed

Yeah, but Pilgrims didn't need 21st century Plymouth just to survive. The environment was habitable. There were local food sources. And while there were new local sources of mortality, they didn't have to deal with anything like ever-present radiation and toxic dust flying around near-vacuum. You simply can't build a Mars colony incrementally. It's too hostile of an environment. You can on Venus, because Venus is very nearly habitable in the cloud layer. But Mars is just too much.

7 hours ago, southernplain said:

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

Well, sure. Once you build something of that scale. On another planet. In near vacuum. In soil whose characteristics we do not fully understand yet. Derinkuyu took centuries to build. And we don't have lift capacity to make the progress a lot faster. Plus, exposed rock as your walls isn't an option. Absolutely everything you build must be air tight. Which means you'll have to deliver materials for structural support, wall paneling, airlocks, etc. Like I said, a better comparison is building an aircraft carrier on another planet. US managed to build a dozen on this planet. I don't think we can be expecting serious progress on it this century.

Venus we can colonize incrementally. We can have first people on Venus next decade who will permanently stay there if desired, provided continued supply deliveries from Earth. It is a simple impossibility with Mars. I don't see how this is even an argument when one can be done in a decade and another takes a century at best.

And it's still life underground in low gravity vs open skies of Venus. Why is this even a contest?

[SunlitZelkova]

16 hours ago, K^2 said:

^* Note that for day-night cycle, we really don't care about planet's rotation, as it's super slow. But the winds super-rotate, resulting in a day-night cycle of about four Earth days. So at equator, the average insolation is roughly 1/2pi of peak.

At the circumpolar regions, the day-night cycle can be brought much closer to Earth's.

15 hours ago, Rakaydos said:

The biggest problem with a venus colony is coming home. Earth equivilant gravity and pressure means you're going to need a superheavy to get starship back to orbit, and the logistics of superheavy launch and landing from an airborn, floating platform boggles the mind. Not to mention SSTOing a superheavy into space to get it to venus in the first place.

Launching Starship from Venus was just a random idea I threw out there. It could be a purpose-built VDV/VAV instead.

14 hours ago, Deddly said:

If the colony is vegetarian, at least to begin with, things get easier but by no means easy. I agree with @GoSlash27 on this one, it is no easy thing to get not just an ecosystem but a complex interplay of ecosystems in place.

Honestly, I don't think they are going to do it. But I do want to see a lot of massive rockets flying and I would love to see a manned Mars base become a reality. Whether or not it ever becomes a self-sustaining colony, I think the journey there will be quite exciting. SpaceX never claimed to be able to do all of it themselves. Is that where they're going wrong, do you think? Perhaps no other companies will be interested in making that kind of investment with so little promise of return? Would they be more likely to get an outpost-possibly-future-colony established by bringing absolutely everything in house? 

 

As for floating cities on Venus being an easier option, not a chance. 

I think Venus might not be "easier", but it is at least similar to the difficulties of a Mars colony.

It is interesting. Both planets have pros and cons. On Mars negatives are the dust and low gravity, pros are abundant resources. On Venus negatives are lack of resources and ascent and descent would be complex, but pros are gravity closer to Earth's and relatively "clean" environment.

I say that because dust will likely get everywhere just as regolith does- a problem that IIRC has yet to be solved, whereas protection against sulfuric acid on Venus could be basically identical to protection used on Earth when handling such materials.

14 hours ago, kerbiloid said:

Basic calculations, please. Mass, area, amount of soil and water, productivity of the support industry.

The words are cheap, the potato costs money.

As I said here-

19 hours ago, SunlitZelkova said:

This is just random thinking based on experience with space history (but not engineering)...

Most of my knowledge revolves around space history and politics around that. Even if those subjects were my strengths, I am not a professional engineer so whatever I come with will likely have a number of metaphorical holes. That said, until it is specifically proven it can not be done, I see no reason to discount the idea.

9 hours ago, southernplain said:

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.

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

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.

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.

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. 

Part of the reason no one has sent much to Venus is because of the reason that I stated- all in support of exploration of Mars which is mainly done for the "because reasons" reasons I explained.

In regards to Venus descent and ascent, there is an excellent proposal here- https://sacd.larc.nasa.gov/smab/havoc/ Using Starship derived modules and Starship itself, this could be very easily realized.

Yes, no one is actually building prototypes, but just because it hasn't been built doesn't mean it should not be "now".

I don't think NASA and CNSA Mars exploration will not benefit human colonization. All of it is currently aimed at a 500-day-ish long expedition. That's not colonization- no one is planning to stay there for longer and no studies are going to happen as to how humans do in the Martian environment until humans actually get there. The NASA and CNSA research that is ongoing is applicable for expeditions but has no relation on colonization.

The Venus structure will indeed need to be shipped there but it is the same case on Mars as K^2 explained in his post.

Interestingly, while health effects of living on Mars are certainly up for discussion, I think "Mars depression"- colonists being miserable- is a subjective matter and therefore should not be taken into account for colony proposals. It's not like people can be forced to go to a Mars or Venus colony- these people will have to no what they are signing up for and be prepared for it. There are people who can and *will* endure either underground or floating conditions, so that aspect isn't really important in colony planning in my opinion.

I like your final statement of your post above. I would like to clarify the only reason I am "against" (more like simply don't support) Mars colonization is because of the abundant problems there appear to be, in comparison with Venus that while it has its own issues, eliminates or alleviates many of the critical ones on Mars. If a good solution can be presented on the problems I would certainly change my mind.

The only issue is there is one issue no one can provide an answer to right now- the "long-term" (for future colonists, just the effects as that is where they will live) effects of 0.38g on animals (whether that be homo sapiens, dogs, or cows). That's not to say 90% of Earth gravity might not cause its own problems, but if living in microgravity is already known to cause issues, then logically it could be theorized there will be some issue with 0.38g as well, so Venus' gravity might be the "least worst".

9 hours ago, southernplain said:

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.

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.

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.

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.

Venus *can* have an Earth-like day night cycle if the colony-platform-balloon is built in the circumpolar regions. I think having a surface is not an automatic convenience for construction. That Martian surface is dusty and will cause problems for construction, whereas damage to construction equipment caused by the environment can be much more easily prevented on Venus.

The reason I raise the problem of gravity is because we just don't know about what problems they might present at all. The question of the thread is "what is SpaceX doing wrong". I am assuming they want to build *a* colony somewhere as fast as possible. If you don't want to spend 20-30 years studying the effects of Venusian or Martian gravity on humans and other animals before building your colony (which SpaceX seems to not want to do), then "they" (the colonizers) would be better off choosing the lowest risk target, which would be Venus due to it being the most similar to Earth's gravity.

Also, just looking at it from a logical stand point, if there are health problems in microgravity, it should be expected there will be some in 0.38g. Likewise there may indeed be some with only 90% of Earth's gravity, but there should be fewer and fewer the closer you get to Earth's gravity.

Venus does indeed lack resources in the atmosphere but for the "first colony" the habitation module-platform-balloon's will be manufactured on Earth anyways, just as it would be for habitation modules for the first Mars colony. Venus *could* have resources not from Venus itself, but by redirecting asteroids to Venusian orbit, mining them there, and then transporting the materials down to the colony-platform-balloon. Heck, even if Martian colonization proves impossible for other reasons, mining facilities could still be constructed on Mars, and then although Mars' environment prevents ultra-long-term habitation, the resources could be put to good use on (above) Venus.

Now if the goal is a self-sustaining colony that idea doesn't work. But a Mars colony will have a number of problems becoming self-sustaining too, so instead of aiming for a "bunker-like" colony that is completely self contained, I think it would make more sense to expand not just living space/habitation but the whole of human society into space- including mining, space travel itself (Starship factory on Mars, just to list a random idea), etc.

If we can renegotiate the Outer Space Treaty and establish something like "Kasei Prefecture, Japan", "Mars Oblast, Russia", "Ares State, USA", etc. in space, I think that would give humanity a much better chance of *surviving another* extinction level event than just building what is somewhat of a nuclear bunker on Mars.

1. The only reason the Marsquake detected was so small was because it was likely on the other side of the planet. Just as earthquakes are detectable across the Earth- the USGS reports on the earthquakes caused by North Korean nuclear tests, not the South Korean counterpart to USGS- Marsquakes may be very strong where the hypocenter actually is. This is quite problematic- it is not safe to say "they might be weak" and then design a colony assuming zero seismic activity.

2. I only mention this because I assumed an SSTO on Mars would be needed for P2P between Mars colonies. I now realize what you meant, so scratch that point

3. The thing with the ISS is that those people want to be there and go through much training, and are psychologically prepared to die (they write "in case I die" letters apparently). Not only will the first generation colonists possibly consist of average people, but you have to deal with the next generation born at the colony (assuming pregnancy and child development can actually go forth in 0.38g). Can a 14 year old second generation colonist, already going through the complexities of modern human adolescence (which will likely be brought along to the colony) be able to handle knowing that just an undetectable defect in the hab module might kill him/her? I think it is best not to wait and find out.

4. Fair point.

I mentioned that point about gravity and caution and what not because SpaceX's plans do indeed involve throwing humans at Mars and seeing what happens. The first human landing on Mars was originally scheduled for 2024, but Musk not that long ago mentioned they are now targeting 2026- and both of those are not experimental landings, they are the start of colony construction.

Responsibly, even for a Venus colony it would be best to spend 20-30 years with just a research outpost before attempting full scale colonization. I say this because despite the "lag" in space development caused by lack of government interest being one of the main reasons we haven't been beyond LEO since 1972, a number of important discoveries continue to be made on the ISS, namely in regards to human/animal health in space, that impact Mars (and hypothetically Venus) mission considerations.

Now of course their plans could change when Starship is operational and they actually get serious about base/colony design, but there is no sign of that right now, thus I mentioned it.

9 hours 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.

I think if we are building kilometer sized balloons to live in, it shouldn't be too hard to redirect asteroids to Venus orbit to mine from.

I think self-sustaining colonies- nuclear bunkers in space, to certain extent- right off the bat is unfeasible. It would make more sense to slowly expand into space without the expectation of self-sustaining capability, and then eventually, Mars and/or Venus could be so built up that if some natural disaster like an asteroid strike destroys the Earth, Mars and/or Venus will be able to be fine on its own, albeit under emergency circumstances.

Edited July 14, 2021 by SunlitZelkova

[K^2]

39 minutes ago, SunlitZelkova said:

At the circumpolar regions, the day-night cycle can be brought much closer to Earth's.

Yes, but way less light and more weather. And anywhere between equator and poles there is considerable air current moving towards the poles at relevant altitudes. Staying close to the equator allows you to do minimal station keeping while maintaining exceptionally calm atmosphere. Not to mention it's your best place for both launching to orbit and receiving freight from orbit.

47 minutes ago, SunlitZelkova said:

On Venus negatives are lack of resources

It's all relative. I would argue that carbohydrates are actually easier to get in moderate quantities on Venus. On Mars, you might be able to get large quantities of ice, but that would require a fairly polar region to have it in good quantities, which is an inconvenience, and it's all going to be dirty ice, so it's still a process. While CO2 extraction is going to be a pain at these pressures. On Venus, water for food and plastics required for upkeep is reasonably easy to extract from the clouds, while CO2 is available in spades. If you want to get enough water to make fuel, you'll need large collectors. So that's definitely not an option early on. But on the net, it still seems easier to get early fabrication going on Venus. And for colony sustainability, having easy, reliable way to fabricate materials for repairs ranks way higher for me than ability to build new structures from scratch and to refuel rockets.

That said, yeah, Mars beats Venus in variety of what's easily available. Again, Martian dirt is going to be everywhere meaning that even if your minerals are right there it's actually going to be work, but not as much work as on Venus. Eventually, I suspect a Venusian colony will start dropping drone scoops that will bring up dirt and minerals every time the colony passes overhead, but this is maintenance and maybe slow growth kind of quantities. Venus isn't going to be a booming industry without influx of off-world ores.

That said, given how easy orbital mining is in comparison to ANY of this, I'm not convinced we'll be doing a lot of that in gravity wells by the time we're seriously expanding our off-world colonies. So this might all be a moot point.

[mikegarrison]

5 hours ago, K^2 said:

You can't progress from one to the other on Mars. You can't just keep landing modules on the surface and assemble them together like in a bad sci-fi movie or a game. To survive long term on Mars, you have to go underground. That means digging out thousands of metric tons of dirt, assembling structures underground, then covering them back up. You need digging machines to do that, which needs their own infrastructure to support, and you'll have to bring thousands of people for short term stay to operate all of that machinery, oversee construction, and possibly do some manual work that the machines aren't specialized for.

No, you don't need thousands of people to do that. You need robots. Robots that don't need oxygen and don't care if they get a bit irradiated. Have the robots build the shelter before you send the people.

[kerbiloid]

8 hours ago, Rakaydos said:

Not all at once, but it does have the habitable volume of Air Force One.

Yes, it has enough room for a single-day flight.

5 hours ago, Rakaydos said:

Yes, the things look running exactly this way.

(Of course, if somebody indeed plans the Martian flight).

Starship is 9 m wide.

How much wide is it when put a radprotection inside?

Apollos were cowardly waiting for the calm Sun period, to quickly sneak to the Moon and back in a week.
The brave Starshippers will be starshipping for years. Both solar flashes and background gammas will there in their time. A better rad-protection is needed.

12 hours ago, southernplain said:

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.

That's the answer to another thread: how to name the extraterrestrial cities.

Roanoke, Jamestown...

At least, the end will be same.

***

The vegetarian colony is not for Mars, it's for Venus.

Cuz sounds nice: Venus Veganus.

[mikegarrison]

Also, you are just not going to get people to sign up for going to another planet and then not even being able to set foot on it.

[K^2]

5 hours ago, mikegarrison said:

No, you don't need thousands of people to do that. You need robots. Robots that don't need oxygen and don't care if they get a bit irradiated. Have the robots build the shelter before you send the people.

And if the robots break? More robots? We can't build robots that don't require human maintenance down here on Earth. What makes you think we can do it on Mars? I mean, sure, if it's a multi-generational project, maybe we'll come up with something substantially better. But again, we can build sustainable - not self-sustaining, but truly sustainable long term - colony on Venus with tech we have right now. We do need a larger lifting rocket, but if SpaceX gets Starship to fly, that basically solves that problem. So we're back to the simple fact that sustainable colony on Venus by the end of next decade is something we can pull off if we re-task existing budgets, and it would be something we can grow incrementally. Sustainable long-term colony on Mars might not be possible this century, and we have to build most of the infrastructure before we send in people.

[Rakaydos]

19 minutes ago, K^2 said:

And if the robots break? More robots? We can't build robots that don't require human maintenance down here on Earth. What makes you think we can do it on Mars? I mean, sure, if it's a multi-generational project, maybe we'll come up with something substantially better. But again, we can build sustainable - not self-sustaining, but truly sustainable long term - colony on Venus with tech we have right now. We do need a larger lifting rocket, but if SpaceX gets Starship to fly, that basically solves that problem. So we're back to the simple fact that sustainable colony on Venus by the end of next decade is something we can pull off if we re-task existing budgets, and it would be something we can grow incrementally. Sustainable long-term colony on Mars might not be possible this century, and we have to build most of the infrastructure before we send in people.

We don't make humans that don't require maintenance, either. Zero maintenance is a trap that needs to be avoided. Instead, you design for automated maintenance- parts being replaced of off the shelf plug in parts, which can be installed by another (or even the same) robot.

[K^2]

10 minutes ago, Rakaydos said:

We don't make humans that don't require maintenance, either. Zero maintenance is a trap that needs to be avoided. Instead, you design for automated maintenance- parts being replaced of off the shelf plug in parts, which can be installed by another (or even the same) robot.

This exact idea is at least a century old. I'm not saying it's wrong, mind. Just that we haven't made a whole lot of progress on it, and it's unreasonable to expect that it would be resolved in the next decade or two.

[wumpus]

19 hours ago, Rakaydos said:

Not all at once, but it does have the habitable volume of Air Force One.

I'd assume that for long-haul spacecraft, the volume targets should  be based on submarines.

And to "help Musk", I'd suggest building habitat modules similar to ISS, firing them  up on a Super Heavy Booster (plus some expendable 2nd stage) and connecting them up in orbit (right now the only technical option is alongside the ISS.  That would be politically tricky.

Note that such a habitat can be reused, see the Aldrin cycler.  Of course this means you also have to pay all the delta-v to get to it, so presumably you can take your "100 passengers" and with enough refuelling pay the ~13,000 m/s delta-v needed to go from sea level to Mars intercept and dock with the cycler/habitat (hope it is big enough for 100 passengers).  How to return the Starship is up to you, and docking it and using it as a "Mars shuttle" makes the most sense (and don't be surprised if you need a lot of Starships to shuttle to the cycler to meet the window requirements).