KerikBalm

There are several features that suggest its meant to be some sort of ice of q volatile, and co2 and nitrogen ices would make even less sense

No, it's not. My suggestion was sort of a joke.

Moho, the transfer window is likely to be sooner than the others, and the trip is faster. You should have all the tech, make sure to bring plenty of dV

This would be great as a moon of a gas giant (GP2 for Kerbin system, or in another system)... but I'm not such a fan of replacing a Ceres analogue with this. Where is the old dres canyon? you can't get rid of that... Why is there what appears to be ice on the surface? Assuming solar irradiance at kerbin = solar irradiance at Earth (seems to be that way based on Kerbins appearance, and values in the game files), the Kerbol system's frost line should be around 5 "KU"s. No ice on the surface of Dres (you've previously called minmus icy too... wth?) https://en.wikipedia.org/wiki/Frost_line_(astrophysics) The body itself does look great, I'm just not happy with its placement.

I don't think they are going that way. They seem to be going with a resource based system instead of funds, we already know some parts need "uranium" (not some generic "blutonium" like in KSP for the RTGs), they've said certain resources will need to be made off-world, I htink there was something about mining gas giants (He3 most likely). Orion drives are very unlikely to share a generic fuel with other engines... it seems very likely they will have multiple specific fuel types to fit in with some light colony building+crafting system. I suspect what resources are available ot various colonies will influence what drives you use in-system. There's nothing unrealistic about a generic name. The less specific you are, the less likely you are to contradict reality. If they renamed Metallic Hydrogen to "purple space magic", or a more scientific sounding "Ultra-energetic liquid fuel", then at least it wouldn't be contradicting known science. They very likely did go with Antimatter drives, which is *less* magic tech than metallic hydrogen drives. This belief that they did go deep into the science of it is exactly why I have such a problem with it. People think its realistic because all the other stuff in KSP has been so realistic (except for throttling range and restarts of LF engines in KSP, Ion engine thrust, and scale - all of which people can easily realize are unrealistic concessions to gameplay). Nate's only statement on MH so far has been that it "exists", and that's good enough for him... which shows that he doesn't know what he's talking about, because the question isn't whether metallic hydrogen exists, but whether it displays substantial metastable properties at low pressure. Without such properties, the tech is literally the same as a rocket powered by a can of compressed air (you just have a super-duper- ultra strong can so the air is like really really really compressed... yea, ok). +1 A major problem with the world right now is the dissemination of misinformation. They are attempting to portray this as real science, when its not. IMO, I'd rather have the MH engines be titled the "unicorn fart engine", and then I'd have no problem with it... but I can go for purple space magic instead. Nobody would be mislead into thinking that in a few decades we'll have this awesome fuel type that will be environmentally firendly and replace haydrocarbons, no lifestyle changes are needed, technology will save us, etc. There is so much misinformation in today's world, it sickens me, and this is just another example. After this post, I will no longer reference Metallic Hydrogen engines/MH as portrayed in KSP 2 (I may refer to real properties of MH). I will hanceforth refer to the KSP 2 engine as the PSM engine or purple space magic engine. Ummm, no you can't get the same dV with any upper stage LFO engine. Its only if you need a kerbin relative TWR of over 0.7 that the LV-N becomes uncompetitive. Any they did this for gameplay. Real NTRs (even standard solid cores) could get much much better TWR. They basically took the stats of the NERVA, and ignored even more advanced designs like the MITEE and Timberwind designs, or generic pebble bed designs (particular pebbles with molten cores and a shell of a material with a very high melting point, like tantalum). They also ignored chemical-nuclear hybrid designs like the LANTR. If you want better than the LV-N, there is no need to add the PSM engine. FYI, there is no need to add radiators for LV-Ns anymore. Realistically, you'd need radiators during start-up/shutdown, when liquid hydrogen propellent isn't flowing past the reactor, but not during operation. I actually liked that restriction, as you then needed radiators to use the engines (although, at unrealistic times), but then I'd also lower their mass back down to 2.25, not the current 3 tons.

Failed re-entry of the first stage of a re-usable 2-stage Eve cargo carrying spaceplane: The design was workable, just a matter of proper ascent/descent profile, and piloting.

So you couldn't remember European Space Agency, and went with United Nations instead? Okay... I don't get it, but... Ok

What does that have to do with anything? Interplanetary travel is already easy at 1/10 scale with chemical rockets. Sure, OP rockets can make it easier, but that doesn't mean much. With the same logic, I can say a magical unicorn fart engine must be included to make interplanetary travel even easier. Also, if its thrust into on rails, burn time isnt so important ad transit time, and something like a nuclear piwered vasmir will be faster. As would a gas core ntr

Such as with a gas core NTR? Or as it already is at 1/10th scale with a poodle? Or as it would be with thrusting-on-rails nuclear powered Ion engines? Or Orion pulse drive... etc. We don't need metallic hydrogen for easy interplanetary travel... particularly with the ability to set up colonies on planets.

I am only looking forward to the atomic rockets. The metallic hydrogen engines need to die. An Isp of 1700s, with no way to contain the exhaust and stop it from melting the engine. "Cesium doping" for magnetic confinement makes no sense. Even if we were to accept MH metastable at low pressure (which I don't), 1700s Isp involves yet another layer of magic.... Meanwhile one could just mix the hot MH exhaust with normal liquid hydrogen (you could store hydrogen Ice if you want some more density), and have a non-magic solution to keep your engine from melting. The Isp in that case is still a very respectable 1100-1200s. They've shown the "atmospheric" variant mixes exhaust with water, that would provide more TWR at lower Isp (500's). That could have been a simple, non-magic way to have variants suited for different purposes, but nope, they went with magic err magnetic confinement of non-ionized hydrogen by throwing some cesium in there that wouldn't be bound to the hydrogen yet somehow enables it to be confined (if it was bound, the Isp would be terrible, and less that of the water engine). Which is what the most recent experiments observe. Not to mention that there hasn't been a theoretical prediction of low pressure metastability for more than picoseconds since the 70's I disagree, suspension of disbelief is very important, and that is related to perceived realism in many cases. In a game like this, realism is very important for certain aspects. I can accept unrealistic planets as fun engineering challenges (like Tylo... that should have an atmosphere, but whatevs... also, the moon seems unrealistically big compared to the planet). What really annoys me is that they could get MH level performance with closed cycle gas or liquid core NTRs, and that would introduce even more gameplay considerations with the radiation concerns. http://www.projectrho.com/public_html/rocket/enginelist2.php#ntrliquid They could throw in a LANTR type NTR, where its a chemical/nuclear hybrid rocket, and you could maybe have your craft lift off on chemical power only before starting the reactors (and thus dramatically increasing the radiation emitted... yes, even a shutdown reactor will still emit radiation if it has been running a while) http://www.projectrho.com/public_html/rocket/enginelist2.php#lantr

Do you mean the ESA? The ESA is not part of the UN.

I feel that liquid hydrogen should be split from the generic liquid fuel, which I would be fine leaving as some kind of generic hydrocarbon (kerosene, methane, butane, doens't matter compared to lH2 NTRs, orion drives, fusion drives, etc). When going interstellar, there had better be some form of life support, even if its just requiring some closed loop life support module/X greenhouses per kerbal. Sending a kerbal to the next star system straped to a chair on the side of a rocket is too ridiculous (granted, I won't even do that in KSP to other planets)

Plus, in stock, mk2 fusalages are pretty much the worst for drag. Their L/D is terrible, you get less drag with a cylindrical fusalage and wings. Cylinders are more mass efficient too. In stock (dunno about FAR), mk2 is for looks, or surviving re-entry. Mk3 isn't great either, but its the only reasonable option for a payload bay that you can reuse (unlike fairings). It will be interesting to see if the fairing changes in 1.10 make mk3 cargo bays a thing of the past

The asteroids in orbit don't count?

No, wing sweep does not matter in KSP. A wing swept at 0 degrees or 90 degrees with the same AoA, will make the same lift and drag. But your thread title asks a different question, if they have an "actuall use in KSP", and the answer to that, is yes. You can use them to shift your center of lift forward or backward, and you can use them to make planes more compact, so that they fit in smaller fairings (in the case that you want to send a plane to space in a fairing, such as a plane intended for use on Laythe)

You can't one shot and get into a stable mun orbit. You need a capture burn. Otherwise you will leave the SOI with the same velocity relative to Mun as when you entered the SOI. As you cannot enter the SOI with a non-zero relative velocity (the mere act of crossing the SOI boundary implies a relative velocity greater than zero, even if it can be arbitrarily close to zero), you will always leave Mun's SOI without a capture burn. Umm, unless you have your Ap wayyyyy past Mun, it will be catching up to you as you near Ap. I prefer to have it catch up before I reach Ap (faster transit), but many encounters will have your craft get to Ap first, and then have the Mun catch up. Ships tend to "hang around Ap" (ie, they spend more time near Ap than Pe), so just hanging around near Ap while Mun comes along is an easy way to do it. I prefer that the Mun Soi comes along and scoops up my craft before it reaches Ap, even if my Ap is around mun orbit. For the lowest dV capture burn, you want the lowest relative velocity when crossing the SOI, so this would mean crossing the SOI right when you reach Ap, meaning your Ap shoul be right at Mun's orbit. FYI, the Mun has 0 inclination to kerbin's rotation, if you get into orbit of kerbin with no inclination, you're already aligned with Mun. Its Minmus that you need to worry about.

a 2nd physics bubble running on another core, improved SAS control, and automatic maneuver node execution... So I can push recoverable 2 stage designs even further in stock. What I most want is improved performance, but for engine optimization, it seems KSP 2 is where I'd have to look.

My re-coverable 6.4x spaceplane: Climbing on airbreathers: Rapiers to closed cycle (after the Rhino already fired) Getting the Ap up, but also getting some horizontal velocity Orbiter decouple: Almost to orbit? still 1000 m/s to go Nearly there, lets check in on the 1st stage: 124.9 km altitude, plenty of time to switch back (when I was taking a 72 ton payload, it would be approaching 30-something km at this point, and most of the time, I'd be a little too slow to switch back) Orbit, with 54 tons of leftover fuel (61 tons of fuel + un needed tank mass, and then lets say -5 tons for de-orbit). Slowing down the carrier stage: Turning back to KSC: Engine relight, high speed cruise back: Made it with plenty of fuel: maybe I can load a bit more oxidizer to increase payload. Lets say another 1000 units, maybe then I can have enough time to swithc back when the orbiter takes more payload Ok, so I overshot and had to turn back around: 27 minutes total, a lot done at 4x timewarp during the high speed cruise back to KSC. Also since i landed on the KSC flat, I spend a significant amount of time turning around and taxing back to the runway.

So, in my adventures playing with scaled up systems and the resulting low payload fractions of SSTOs, I started playing with re-usable 2 stage to orbit craft (a suborbital "carrier" and an "orbiter" that reaches orbit fast enough to switch back to the carrier before it falls too deep into the atmosphere. In such a setting, "go anywhere" craft are a bit out of the question, as you leave a large portion of your craft behind (even if it is reusable). My carrier craft have all the airbreathers, but those air breathers are all rapiers that go into closed cycle to boost the Ap higher and get the orbiter even closer to orbital speed. So it occurred to me... the unloaded carrier craft may be able to achieve orbit on its own with no orbiter. So, I started working on a new mission profile: Carrier goes suborbital, orbiter gets to orbit with good fuel reserves. Carrier lands, refuels, and goes back to orbit with basically no fuel left. Orbiter and carrier rendezvous. In this case, I get the entire craft to orbit (like an SSTO), but its more like 3 stages, and 2 things get to orbit. When the orbiter is carrying a detachable payload... this can be carried even further. 2 stage to orbit: decouple payload (Staging event?). Land orbiter and carrier. 2 stage to orbit again, Orbiter (with more fuel) redocks with payload, carrier lands and refuels. Carrier SSTOs, and redocks with orbiter plus payload. If the payload is a fuel tank, this can give the entire setup a substantial dV margin. What would you even Perhaps a reusable craft to anywhere can be done in 3x with stock parts? (granted, it won't be coming back from Eve). Has anyone done mission profiles like this? or is it simply too much work to go to orbit, leave as much up there as you can, come back down, refuel, then go up again?

Umm... they still exist, in the case of them being equally massive, you have a point orbiting the barycenter, equidistant from both.

L1-3 are also unstable Indeed, but since L1,2, and 3 aren't stable, but are still usefull, then L4 and L5 should still be usefull as well According to wikipedia, the ratio between the primary mass (such as the Sun) and the secondary mass (such as the Earth) needs to be greater than 25:1. If we have yet another massive body (call it the tertiary mass) at the L4/5 point, then the secondary to tertirary body needs a mass ratio of >10:1, from what I read on the Theia impact hypothesis. Here is a diagram tht helps to explain where the L4 and L5 points are: That its pulled to the barycenter (Earth+Moon mass tugging on it), and not the Earth, is what allows it to be farther from the Earth than the Moon is, and still have the same orbital period as the moon around the Earth. With the bodies on rails, you just need to have them on rails aroun the barycenter, and it will work out again. Stock bodies don't have this behavior, but they could.

Yes you can, but they have to orbit the barycenter, which isn't the stock way. You could put them on rails orbiting a barycenter

I'm pretty sure I'm just paraphrasing some quote from somewhere else. I take no credit for inventing it. Feel free to substitute a grain of sand on a beach, or whatever

This analogy and reasoning, IMO, are terrible. First, I would say neither are virtuous. They both just need to do what they need to do. Second, you are not powerless. Your power is miniscule, more like a worker bee. Alone, a nuisance, but in a swarm, powerful. Just look at the protests in the US against the police. More police reform has already happened due to them, htan in the last decades without them. Police that would not have been charged with crimes are now going to trial, there is a collective power. Until robots replace us, the power lies in the collective behaviour of the people. Your analogy, correctly interpreted and ignoring the flaws that I see in what constitutes "virtue" would be: "YOU CAN NOT BE VIRTUOUS IF YOU ARE POWERLESS" Your modified version leads to, IMO, what is wrong with the world today. "I'm powerless to stop climate change, I might as well drive an SUV instead of a hybrid, or taking a bike; and there's no point in conserving energy" "I'm powerless to stop overpopulation, I might as well have 3 or more kids" "I'm powerless to stop polution, I might as well use a bunch of plastic and not bother to recycle things" etc.... You may be a drop of water in the ocean, but what is the ocean if not a collection of such drops? On the other hand, the ethics of video game developers is an issue of very little importance when compared to climate change, overpopulation, pollution, etc... so I can forgive apathy in this particular case.

Tried my hand at a 6.4x rescale after seeing some comments from @Northstar1989 (the atmosphere was only rescaled1.25x), but everything else was stock (no changes to part performance, no FAR). Took my 3x 2 stage recoverable design, filled up the tanks and added a little more fuel capacity, and was able to get 72 tons to orbit, but it seems like I would lose the 1st stage 9 times out if 10 as the 1st stage gets deleted just abut the same time that the orbiter gets to orbit, only once did I switch in time. Scaled the payload back to 54 tons, and with a ~650 ton starting mass, I got to orbit and recovered the launcher. Im thinking about doing 4x from now on, then the rotation period should change by the nice and even number of 2, instead of some irrational sqrt(3) or sqrt(6.4)