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Why would it have the density of Kerbin? The only reason Kerbin has an absurd density is to give it the same surface gravity as Earth despite its miniscule size. The whole point of a real-sized solar system would be to not have planets made out of unealistic materials or suns that could never sustain fusion. Talk about reality! You're working from the assumption that everything has to be the same as the Kerbol system. Me and others don't—that's the whole point of other systems. In KSP1 you're forced to replace the Kerbol system with a modded version if you want something Earth-sized. For the record, personally I don't care. I see great opportunities for KSP2 for someone to introduce a modded system that has solar-system like properties without replacing what we already have but you're telling me they can't because that would break the rules you have about the Kerbal "universe?"

Trina Ray (lead scientist of Cassini's Titan flybys) gives a first hand talk about a few of the fantastic findings of the Cassini-Huygens mission. She talks a lot about how people reacted to the data as it unfurled and slowly pieced together some rather amazing big pictures. It's lovely, figured I'd share!

We should probably talk about colonies and career mode somewhere else since this is about heat. But no you aren’t understanding the way that plays out. There have been a huge host of improvements big and small, but like I said they’re just buried in bugs and rushed execution. Again if you want to talk about that we should do so elsewhere and not clog up the thread.

I already listed some examples earlier. Now you can say “Well that’s just Elon time/talk”, but the fact remains he does say these things, regardless of whether they are realistic or likely or not.

Ewoks dont talk english and yet in sw: ewoks they talk english because otherwise no one would watch it. Its the same logic as that. Its also the same reason english people dont watch films in french or german because they dont understand it.

Do you expect this would happen? Seems unlikely. As for kids born there... they would be outside of law here anyway. Ask the Martian courts I guess <shrug>. I have concerns about this as well. We have no idea if Martian gravity is even safe long term. We have an N of ~78B for humans in 1g, and an N of a few hundred (times whatever the average stay in space is) for microgravity, and an N of a few days times 12 guys in 1/6g. If I were working on Mars as a plan, I'd build a space station with a couple Starships tethered, and spin them up to 0.38g and raise some animals, breed them, etc, and see how it goes. Otherwise send the human exploration teams (adults would would want to go anyway, even if just to visit), and raise animals as part of the research. The early colony dev missions build infrastructure, and raise mammals to test for bone loss, etc. This lasts enough synods to get good data before people talk about having kids on Mars. Under the assumption you are not a parent, I seriously doubt any parents would knowingly put their kids at extreme risk. So I don't see a family moving to early Mars habitats (once it's safe as airliners to get there, and decades of people living there, maybe). Choosing to have kids on Mars? Maybe some will as long as returning to Earth is an option, but if the safety of that is marginal, who would take the risk?

You are correct in that technically, society doesn't have to do anything. It can just be a way for analysts to group humans who live in the vicinity of each other and maybe say hi from time to time, but otherwise leave each other alone. But historically, society does indeed have a responsibility to protect children. This is why the whole concept of adulthood exists, because children below a certain age are not ready to do things on their own and need to be watched over by both the parents and tribe. Parents alone cannot be trusted, which is why things like Child Protective Services exist. No one under 18 can sign a waiver. Sending children to Mars would be unacceptable (see below for more explanation of this belief). As I mentioned earlier in this thread, SpaceX has said they want to skip a Mars research base and start right off the bat with a town on Mars. Given... certain aspects of human nature, this is going to result in pregnancies sooner rather than later. And yes, you can argue there will be a research base and plenty of study on how best to build a Mars city first, but that's only speculation. What we know is that SpaceX wants to build a Mars City as quick as possible to the point of proposing something as ludicrous as people living in the landed ships on the surface right off the bat. They said they wanted to catch Super Heavy with the tower equipped with "chopsticks". And they actually did it. I think I myself and anyone else who thinks SpaceX has the potential to be negligent in how they handle going about building their city are not unjustified in doing so. Why are you blowing this up to include space travel as whole? I said I didn't care if adults on research expeditions get blown up. Yes, that will continue to happen no matter what, and I don't believe there is a point in stopping just because of that. What worries me is colonization, which will entail moving people and their families, in all likelihood including children, to Mars. SpaceX is known for moving fast and breaking things, and that's fine with the lives of adults who sign waivers, but not for children, whether they launch from Earth and journey millions of miles or are born into a situation they had no choice in in a small habitat on Mars. Actually, I will back off on the children who on born on Mars. Just as it is simply nonsensical to use regulation to prevent people from being born into inhumane situations on Earth, that notion that allowing people to have children on Mars would constitute a negligence society needs to intervene in was wrong. However, I don't believe children should be allowed to be colonists insofar as there is a possibility of true negligence (negligence they could be held legally accountable for). I do think any Mars colony would involve sending families to Mars. They aren't going to just pick bachelors or 20 something year olds. They're going to want "millions" as they say, and they are going to need people with various different skills, some of which can only be gained after having lived enough of life to have had a family. I don't believe anyone would dump their family for living on Mars, and therefore would desire to bring them along. Musk doesn't really seem to like ethics, preferring efficiency, and I could see him allowing children to travel there. And then if the Mars hab explodes because of some defect brought about by a lack of care purposefully overlooked, the blood will be on our hands for having failed to prevent this. This would be as irresponsible as allowing children to participate in some exotic tourist attraction that is normally reserved for adults who can understand and sign a waiver. If Musk does indeed limit colonists to bachelors and 20 something year olds, neither without children, my concerns will be addressed. But there is no reason to believe that will be the case. I think he would value skills over demographic questions and just send whoever is willing*. Is there reason to believe Musk will send children to Mars as colonists? No, but as I said, we hold these discussions even if the scenario in question is purely hypothetical, just as we talk about the possibility of AI rising up and turning on humanity. *To illustrate this concern, let's say as part of making the city a backup for humanity, he wants to send five physicists to Mars. Maybe he finds one who is a bachelor, but if there are four others who say yes but want to bring their families, is he really going to say no?

Ah, yes "I think you're boring so let me talk about a stupid trend that's absorbing the minds of millions of children" Find better friends if that's how they treat you

Ah! My bad! So this will be the "A TOGGLE BUTTON THAT CAN BE OPERATED BY THE PLAYER TO TURN ON AND OFF A FEATURE THAT IS INTENDED FOR PEOPLE WHO FEEL MORE COMFORTABLE PLAYING THE GAME WITH SOME ADDITIONAL HELP AND TRAINING" button then? But we do need to talk about the "A TOGGLE BUTTON THAT CAN BE OPERATED BY THE PLAYER TO TURN ON AND OFF A FEATURE THAT IS INTENDED FOR PEOPLE WHO FEEL MORE COMFORTABLE PLAYING THE GAME WITH SOME ADDITIONAL HELP AND TRAINING" button popup text balloon text in that case...

Envelope math time. Let's go worst case scenario here. Starship radiates no heat, reflects no heat, and has 500 square meters of area exposed to the sun. 1380W/m2 hits Starship from the sun, for a total of 690000W. The latent heat of vaporization of oxygen is 214,000J/kg, and Methane is 510,000J/kg. Oxidizer to fuel ratio is roughly 3.5, so average latent heat of vaporization is ~280,000J/kg. In this scenario where zero mitigation is taken and all of the heat hitting Starship goes towards boiling off the propellants, Starship loses about 2.5 kilograms per second. It will spend ~60% of its time in sunlight (probably a bit high, but again, worst case scenario), so a whole 129.6 tons of propellant is lost from Starship per day. Starship would have to launch nearly one refueling flight per day just to keep up with the losses, in the optimistic 150 tons to orbit reusable config (about the higher end of what has been estimated for reusable mode). This is obviously not a realistic scenario, but it highlights how conservative assumptions can lead to large estimates. Stainless steel has something like an albedo of 0.6 (60 percent reflected, 40 percent absorbed), and with the nose facing the sun at all times, the exposed surface area is about 64 square meters. This decreases the incoming power to around 36000W. Starship will also naturally radiate some heat away. LOX is about 54K, CH4 is around 90K, some of the ship isn't up against cryogens at all, but I will assume the ship's skin is at an average of 60K, conservatively low. Stainless steel's emissivity, I'm finding a large range, let's go for something conservatively low at 0.55 (values up to 0.85 are reported). Starship's surface area is about 1500m^2, it should be higher probably, but again, conservatively low. Plugging those into the Stefan-Boltzmann equation gives a radiative flux of, uh, about 600W. Not great. Radiative flux scales with temperature to the fourth power, but we still won't get nearly enough flux even raising the entire skin temperature to 110K, the upper end of methane boiling temperatures. One thing that could be done is to have a double hull for the nose cone, which is pointing towards the sun here, which is moderately well insulated from the rest of the tanks. This could even be done by just having the nose cone empty as with a normal non depot starship. The interior would be coated to reduce interior radiation transfer. This would allow the, worst case scenario, 64 square meter circle to get much hotter than the rest of the ship and radiate more effectively. The nose is conical, but I'm not sure how to do the math on that, so I'm going to take the volume of an equivalent sphere (should be roughly equal to that of a half sphere stretched by a factor of 2, but not exact). This gives a surface area of about 250 square meters. To offset the rest of the flux from solar heating, the nose would have to rise to about 260-270K. Conduction to the rear of the ship over the surface area of the very thin tank walls (let's be extremely generous and assume 5 centimeters thick taking into account internal radiation bypassing the nose shield and stringers and such) (surface area ~1.4 square meters) (90K CH4 tank immediately behind 270K nose cone) will be calculated also. The section between the tank and the nose is, what, 10 meters long on an unmodified non depot starship? The depot one may be different but the extra length helps us here. Heat getting to the fuel is now 369W, and as we found earlier, Starship radiates about 600W by itself. Even assuming it doesn't, we have reduced the boiloff, in theory, to 114kg/day. Even if I'm off by a factor of 10, just by pointing Starship in the right direction, with not that much modification, that's like a ton of fuel per day, which is well manageable. Unfortunately, it isn't that simple because the Earth is reflecting and radiating heat as well. This ends up totaling roughly 345W/m2 averaged over night and day at the surface, as the Earth is (mostly) in equilibrium, and has four times as much surface area as it does cross sectional area. If Starship is 400km up, this decreases slightly to about 305W/m2, although the atmosphere is further out than the surface so it will be a bit higher than that. Now we get into the wonderful world of materials having different reflectivities and emissivities for different wavelengths, and I'm going to handwave this and say everything is the same as it is coming from the sun. Starship is pointing at the sun, so can't really control its Earthwise orientation. Averaged over the orbit, I'm going to assume an average Earth facing cross sectional area of 300 square meters (450 is the max, 64 is the minimum, approximately at least, this whole post is filled with approximations). With the same albedo of 0.6, Starship will receive an average of 36,600W from the Earth. Due to our solar mitigations, assuming they actually work, the Earth radiation now dominates and is much more difficult to protect against. It is possible the heat shield has better radiative characteristics and could be oriented towards Earth for maximum effect, but the depot probably won't have a heat shield... It could have some other thermal protection in its place, though. This is beyond the scope of my analysis. Total power reaching the fuel is roughly 36,600-600+370 = 36,370W. This is about 0.13kg/s, or 11.2 tons per day. Not great. If we conservatively estimate 100 tons of propellant per trip, and a full load of 1300 tons required, that is 13 trips for the principal, and then 1 more trip for every 9 days it takes. If we assume two ships per week, or one ship every two weeks from each of the four pads, that is a total of 22 refueling launches over the course of 77 days if I did the math right. Keep in mind that this is all an extremely rough approximation, but it shows how upper teens could be a realistic number. High ones could also be realistic if the assumptions on capacity, flight rate, load needed, and thermal protection were changed. We simply don't know enough. If my calculations are correct, and Earth heating is the driving force, deep space boiloff should be incredibly minor. Unfortunately this means pointing the crew compartment at the sun, which is explicitly what they talk about not doing for Mars.

What I mean when I say “propaganda” is that it is only words. There is no “Mars fund”, and no deep engineering work is going forwards right now. Can Starship get to Mars? Yes. But it’s not it’s main purpose right now. In a practical context, IFT-2 brings Starship no closer to Mars than Artemis I brings SLS closer to Mars. The only difference between the two is Starship actually has the launch cadence to do a Mars mission. But the two are quite similar, with Orion CM-001 being a test vehicle in a similar manner to Ship 16 or whatever number this one is. Lucrative may be the wrong word, but the way I see it is this: satellite launches make money, sending stuff to Mars doesn’t. Unless you have another company doing the Mars research and building, but none exist right now. If there isn’t a space launch market taking advantage of Starship rapid reuse, I really have to wonder how Musk plans to fund his city. The City is the only thing I question. With Starship ready, it would be much easier to get a NASA-run Mars “research” mission (normal expedition) funded by the government. The low cost created by something like a “Commercial Mars Crew” or “Commercial Mars Surface Services” program might make a program palatable to Congress, whereas a Mars program in the style of how SLS is being done would be too expensive. To put it another way, I don’t doubt SpaceX will be capable of sending scientific payloads to Mars one day, and maybe crew on a government sponsored expedition, I just think Musk’s city plans are mainly talk at this point. It’s more of a “I’ll believe it when I see it” thing, compared to how I am more inclined to believe in uncrewed Martian surface delivery services. I’m a big Venus colonization fan. I’m highly skeptical of the ability of humans to give birth in 1/3 G or lunar gravity, so if there are going to be colonies on a planet instead of in orbit, Venus is the place to be.

All the talk on here of Mars colonies begs pointing out that Venus is in a lot of ways more habitable than Mars... The 60 km altitude level in Venus' atmosphere has comparable pressure and temperature to Earth and an oxygen-nitrogen mix of gas would work as a lifting gas in a balloon there. It also has very Earth like gravity and much better protection from cosmic radiation than Mars. Access to resources like metals would be a challenge, but every off-world colony faces serious challenges of one form or another. Maybe SpaceX's propulsive landing technology could be put to eventual use flying to/from cloud cities on Bespin Venus? Living in floating bubbles there would almost certainly be preferable to moisture farming on Tatooine Mars.

An intuition is not really good enough. Also why did you ignore my sentence where I literally say that I would replace "Cadet" by "Beginner"? Isn't it a good proposition? At least I find it better than "First Time User Experience". The message I'm replying to only talk about the "orientation" part. And to answer you, in my language you won't use first time in there, it would be a bit weird. That's why they translated it to something a bit different. Also cadet is a french word (my language), so I have maybe learned "cadet" before "first time" in english lol (I was pretty bad at it when I was young).

We are not going to talk about it because it is off topic. If we can avoid talking about a certain conflict in the Russian thread, and politics in the Chinese thread, we can do it here. I haven’t seen anyone wish for Soyuz and Shenzhou to explode just because of the politics in those two countries.

I guess we’re also not gonna talk about it here but boy this would be a whole lot easier to get exited about if it wasn’t entangled with the Elons increasingly impossible to ignore moral and emotional implosion. Hard not to root for this thing blowing up on the pad at this point.

https://x.com/elonmusk/status/1110329210332053504?s=46&t=Jd73T2beq0JLNtwTy1uR5A Musk has literally said the city will be complete by 2050. https://www.inverse.com/science/51291-spacex-here-s-the-timeline-for-getting-to-mars-and-starting-a-colony And SpaceX’s chief Mars development engineer has said they won’t start off with a base, but with a town. Musk has said it will only be 10 years before the town would be established after the first crewed Mars landing. Note that he began these proposals in 2019, before Artemis was planned. Musk had no plans for research on the Moon, and certainly not enough on Mars to determine if people can live there. Musk has also said he wants to die on Mars. If he has Starship working after a few development flights, an uncrewed Mars development mission has flown, and rapid reuse is perfected, there is nothing to stop him from his “1,000 ships in each transfer window” plan. He expects a million people to be sent to the planet over the course of roughly 20 years. I still don’t understand this “human nature” argument. The ISS isn’t being used to study specific systems for Mars missions because none are in development. It would be pointless to develop without a Mars program in place. The reason we haven’t gotten a Mars program so far is because we have more pressing problems on Earth. That’s human nature, but only insofar as we take care of each other instead of abandoning the majority of people in the name of “survival of the species”. Speculation is not a replacement for excitement. We have to talk about these things to see if they are viable. No one, whether it be a government or a company board, is going to fund experiments for something that might not even work. Would you fund parapsychology experiments without speculating whether they are even worthwhile first?

In an attempt to talk about anything other than the navball, have you seen the new pictures posted? I'm sure people will still complain about how game xyz is so much better and KSP sux and bla bla bla but I think these are BEAUTIFUL.

NSF coverage is hot garbage. Would be fine minus the yammering... but the yammering persists. Ditto Tim Dodd. Utterly uninterested in hearing them talk.

Calling 911 because nobody understands me when I talk about the inherent superiority of Z gauge over HO gauge.