Codraroll

That, plus buses are heavy. In a collision between two cars, there might easily be multiple fatalities because they bring each other to a standstill or roll-over. While a bus colliding with a car will slow down quite bumpily, but its passengers are not likely to die in the collision. Buses colliding with other heavy vehicles is rare too. Overall, it's just very uncommon for a bus accident to have multiple fatalities.

Nice to have in case the Yetis refuse to submit to the tyrannical authoritarianism of the unelected Beijing regime, I suppose.

It should also be noted that the Sprint missiles didn't achieve their awesome acceleration because they had a "magic" rocket booster. It was more because they placed a dinky little payload atop a honking great booster, and the missile didn't consist of much else to weigh the setup down. If you (somehow) attached a bigger payload to a Sprint missile, the results would be a lot more mundane.

What is wrong with the way we explain things? Time and time again, various members have made it clear that SSTOs are pretty hopeless endeavours and cannot be combined with Orion in any way, shape or form. Yet barely two days pass, and then your conclusion reverts to "I guess an Orion SSTO is the best answer" again, as if nothing had been said to the opposite. Why doesn't it sink in? Is anything unclear about the explanations? To reiterate: 1) An SSTO needs to be as light as possible for the rocket equation to allow the endeavour. 2) An Orion drive is a monstrously heavy thing. It does not play nice with the rocket equation. 3) The Orion drive has various insane drawbacks that make it a stupidly bad idea overall, and any attempts to improve it will make it obsolete instead. Is it 1), 2), or 3) you have a problem with?

Which is why you would never launch something of such ridiculous weight in one piece. What mission types could possibly require that?

Interesting to see a heat graph that middles around 400 kW/m2. For reference, one of these propane burners gives off around 3kW of heat: (Image source) You'd need 133 of them to deliver 400 kW. I don't think there's enough room to pack 133 of those onto one square meter. If the bottle is 5 cm across you could do 20 side-by-side in a meter, but you'd need more than five such rows in the other direction, and I think the burner+bottle is taller than 20 cm, so they wouldn't all fit. Still, they give a pretty impressive mental image of the heating those wing root parts of Starship are going through. Imagine a stack of propane burners packed as tightly side-by-side as possible, and stacked on top of each other, each giving off their blue-hot flames. That's still less energy than the heating faced by certain parts of Starship. Less than half of the maximum, if the graph is any indication.

So, shells loaded from the left. Does that mean an Armata turret would pop up and to the right when hit by ATGMs? Provided it could even make it out of the parade stock warehouse in Moscow without breaking down, of course.

I think you shouldn't rule out the possibility that you misunderstood what he said. Given your reaction (or lack thereof) to the meticulous explanations by sevenperforce and others on these topics, it seems that there are some concepts you should reconsider your conceptions and conclusions about. Indeed. I have seen others try to say the same for quite a while, but it's good to hear it from you too.

Eh, the Russians have been doing the same for decades. The Germans did too. The British before them. Mapping other countries is kind of a thing. I wonder whether the explanation was that they didn't know any better, or that they didn't care. Either way, there's absolutely no way in which this makes "SAST" look any better in the eye of the competent beholder.

Heh, that's one of the cultural things that are different to understand on the other side of the world: the fixation with what we perceive as overly long and detailed slogans. A Western company might put "Seriousness, reliability, safety" as core values somewhere in a document of project values, but rarely more than three individual points, and it'd be seen as overly cheesy to put it on a banner. Writing your goals and aspirations in huge letters on the side of a wall would be quite unthinkable. At least it's even worse in North Korea. "We must work with supreme diligence to execute the plan of the 49th workers' party congress and produce more potatoes to feed the motherland!" or stuff like that seems to decorate every wall over there. If you can say it in a single breath, it's not a proper North Korean slogan.

"We are apparently feeding too much liquid oxygen into the system, and there are fires appearing nearby for reasons we don't quite understand, but really, what could go wrong?"

If I've understood it correctly, it's something like this: He wants a patently unrealistic idea to be a realistic idea. It has repeatedly been explained to him in thorough detail why the idea is unrealistic (I would say "good/bad idea", but everybody keeps stressing that the needs of the plot outweigh everything else, so an unrealistic idea can be a good idea if it makes a good story). But he still insists on applying realism, so we're discussing the real-world merits of the idea rather than its function as a story setpiece. Well, "discussing". It's mostly a many-to-one explanation of where all the hitches are. At times, some of the explanations of why the idea is unrealistic appear to sink in. We've got plenty of people who are good at explaining. Then somebody says something that can be interpreted as an argument for the patently unrealistic idea, or he gets some sort of inspiration on how to slightly alter a minute detail, and spacescifi immediately jumps back to the initial position of "right, then it's a realistic idea after all!", instantly disregarding everything that was carefully explained to him previously. And then we're back to explaining the drawbacks of antimatter Orion SSTOs from scratch yet another time. Try as I might, I do not think I can make a more charitable summary than that. I've seen it play out literally dozens of times by now. It keeps looping back by way of "OK, but if X, then everything you've said doesn't apply after all, right?" There seems to be some fixation on certain ideas and an unwillingness to let them go (or at least, acknowledge their drawbacks) and a continuous re-set to square one. Questions are asked (oh, how they are asked!) but the answers so rarely taken to heed unless they align with the initial notion. As such, it is not really about "efficiency". It's just about the merits of a concept whose merits have repeatedly (Repeatedly! Repeatedly!) been discredited. For the hundredth-and-whatnot time, Orion can work however one wants it to in a sci-fi story. But in real life, there are too many drawbacks and literally any attempt to improve it would make it obsolete instead. And yet, it keeps being insisted that we review the idea that the square peg might fit in the round hole, one more time. That is, at least, how I understand what is going on.

Umm ... literally every single part of this text is badly wrong. Sadly not a fun fact, it would probably be against forum policy to show pictures of what Mariupol, Sievjerodonetsk, Izyum, or Kharkiv looks like nowadays, outside of the carefully crafted camera angles displayed on Russian TV. Mass strikes against civil objects and areas has sadly been a recurring theme from the attacking side in this war.

Here's the caveat, I suppose. According to the rule of thumb of spaceflight, anything announced to happen in two years or more, is just as likely never to happen at all. And up until the moment of launch, delays must be expected (after that, they merely may be expected). Still, three sets of plans independently working towards similar goals is nothing to scoff at. Chances are good at least one will pull through.

In other words, the yard is not in a hurry.

The difference is that NASA actually has money, and the US has a space industry that actively develops new hardware (not just pretends to develop while all the funds are being embezzled).

There's still the Chinese space station, which appears to be slated for continuous habitation. Russia is also dreaming of a space station of its own, although it's still mostly on the "please give us more money so we can make the dream more detailed" stage. And I think ESA, JAXA, and CSA would like to maintain some sort of collaboration about a destination station too, even if they don't have crew rockets of their own to go there.

That is the takeaway, and one you should really take to heart. Also that the merits of the Orion are extremely few, it is useful for only a very specific use case, and there are vast drawbacks. Literally the best answer to any question that involves Orion outside its original use case is "ditch the Orion and never look back". Any technology required to improve it would also make it obsolete. I think that is, essentially, the synthesis of this whole thread, and the answer to most questions you could formulate about it. As for SSTOs, you're at the opposite end of the spectrum. Or rather, in a different corner of the triangle. SSTO is, essentially, "magic" technology, and if you want to make it work, you must cut a lot of anchors to reality. It requires handwaving, and lots of it. Within any level of realism you must forget anything about payloads, there won't be any mass to spare for them. Which brings me to the third corner of the triangle: Realism. You can combine Orion and SSTOs to your heart's content for sci-fi, but it will not hold up to any examination of the cold, hard facts. None whatsoever. Keep it in mind, because you bring the question up a lot. Just, no. It works if you don't care about realism, but it does not combine with hard sci-fi. Again, like improving horseback riding by putting the horse on powered rollerskates. There is no possible way that is a good idea in real life, but it's a good gag for a kids' comic series. So, in the end you have a triangle: Orion, SSTO, Realism. You get to pick two, but you must forget the third one. MUST. If there is a "but what if ...", chances are, the answer is "Nope" with a big N. Just like the rules for the "Cheap, Strong, Light" triangle in materials science. Any combination of two of those properties is going to be deeply negative for the third. We clear?

@Spacescifi, it appears to me like you are trying, on a conceptual level, to answer two questions: 1) Is there any use case that would justify using an Orion drive in hard sci-fi? 2) Would there be a way to improve the efficiency/effectiveness of the original concept? However, it seems like the answer to 2) is quite clear every time: ditch the Orion drive and make a rocket. Practically any technology that could improve the Orion drive would also make it obsolete. It's like trying to make horseback riding faster by putting the horse on powered roller skates. Whatever propulsion method you come up with for the roller skates would make the horse no longer necessary. I think this is basically what @sevenperforce is trying to find new ways to say every time. Orion is an epitome of "cool, but impractical". In hard sci-fi, it could only be justified by having no better alternatives, and as soon as you make a better alternative, you no longer need the Orion. The pusher plate concept is literally the first thing that goes when you try to improve it. That, I think, is the essence of the answer you will get no matter how you formulate the question. Come to think of it, something similar could probably be said about SSTOs, but maybe there are more nuances there.

Thing is, though, that Russia is not the Soviet Union anymore, and it isn't even anywhere close to what the Soviet Union was, relative to its competition, back in the days. It is also no longer a command economy, that can pick the best and brightest out of the universities and send them to the space program to work for peanuts. Instead, the space program of modern Russia is notoriously underfunded, corrupt, and inefficient (That's not to say the US doesn't have similar problems, before Kerbiloid comes with another whataboutist rant, but the US can afford to throw enough money into one end of the program for some results to come out of the other end, despite the massive losses in between). The result is that the Russian space program has mostly "hobbled along" since the fall of the Soviet Union, but even in times of peace and prosperity the gap between ambitions and deliveries has kept increasing, and the budget keeps getting tighter. And now, well, peace and prosperity seem not to be at the table. Even if peace is achieved, there will either be a continuation of the quite harsh sanctions, or tremendous war reparations to pay. Second, I don't think tacking a military mission on will help matters much, because it's not like the military will have money to spare either. The Russian army has essentially been obliterated in Ukraine. Thousands upon thousands of pieces of equipment have been destroyed, including several expensive aircraft and a few quite large ships. Stores of ammunition, spare parts, and various other supplies are being emptied. The deficiencies of materiel in long-term storage (that it's dang near impossible to produce a single working tank from parts salvaged from a hundred rusting husks in a storage yard, never mind that it gets blown up five minutes into battle) have been laid bare. And it is revealed that the air force is incapable of flying complex missions in even lightly contested airspace, effectively implying the bulk of its planes can only be used as expensive airfield decorations. In short, the Russian military will have more than enough on its shopping list for the foreseeable future if it wants to restore even a semblance of what it was four months ago. Being asked to fund a space station in addition to all that would be a very tall order. There might be some funds for satellites and missiles, but a manned space station? Those don't come cheap, and they're not on the "need to have" list by a very long shot. The problem is quite simple: Just Not Enough Money. A space program is expensive, having a large military is expensive, and Russia's economy used to be the size of Spain's before it leapt off a cliff in February. This does not appear to be the right time to try to expand its space program, considering the state it has been kept in for the past couple of decades, even when the country's economy was booming. As you say, the future is very fluid, but it's hard to imagine a path where Russia manages to restore a level of prosperity where it can fund everything a country needs plus a manned space program of its very own. Its behaviour in Ukraine might cause it not to be invited to participate on the ISS' successor. Some cooperation with China might be possible, but as far as I know, Tiangong orbits on a too low inclination to be reachable by spacecraft launched from Russia. A future partnership may thus involve cosmonauts launched on Chinese spacecraft from China, as part of Chinese missions whose main mission language won't exactly be Russian, to put it like that.

Again with the "ooh, our country did great things decades ago while ..." Look at the situation today, and its prospects for improving whatsoever any time soon. Details may be to politics-y to be discussed here, but it seems pretty likely that Russia may not be able to afford a space station of its own at the moment, not with everything else that also has to be paid for somehow.

I guess it's healthy to have ambitions, at least. But colour me a little skeptical of the idea that Russia can sustain a space station as a solo project with things going the way they currently do.

Genuinely wondering if they will ever complete it, never mind launching anything from it.

What even is there money to build these days? Or if the current hodgepodge continues, next year? Or even if the hodgepodge doesn't continue. I wouldn't expect the space program to be very high on the priority list overall.

For a while, I've found the expansion of the universe easier to imagine in one dimension. Imagine, if you will, a telescopic antenna like the one found on portable radios: (from Wikipedia) Imagine you're standing somewhere in the middle, on a telescopic segment that's slowly being pulled out of its neighbouring segment. So are all the other segments, at the same speed. That means that any given points on the segment in front of you and the segment behind you are slowly moving away from you, but the segments next to them again are moving away from you even faster. The segments at the ends of the antenna are moving very fast relative to you, and for that matter, so are you relative to them. The universe is sort-of like that, only the individual segments are infinitesimal but infinitely many. And also the entire thing is in three dimensions, of course.