KerikBalm

Not to my understanding. mH is formed well above 0k at very high pressure. Helium forms a solid condensate just by cooling it for comparison The idea was that you could compress it and it stays compressed, like turning graphite to diamond

I'd rather not have arbitrary limitations for gameplay, that's getting quite far from ksp's realism with simplifications for gameplay. Well, we are talking about something that can't be stored in real life. So this question is a bit invalid from the start. Assuming that it is useable at all, then I have to assume that any spontaneous decomposition would set off a chain reaction, making the entire thing go boom. If it is safe to go on a hohman transfer to something like Plock, then it should be safe for a trip to the next star at .1c with a fusion engine. If your ships don't go boom when forgetting about them in orbit, then I see no reason that you can't bring a good supply of it to the next star system... Other than some arbitrary unrealistic gameplay constraint. I mean, mH is just made by diamond vices here on earth, they fit in a room, scaling that up to make it in large quantities is another thing... But the raw material for mH is just hydrogen, found almost everywhere, unlike He3

Hydrolox would suffer from boiloff, mmH wouldn't, no more than diamond (a metastable compund) does. Even liquid oxygen for methalox suffers boiloff. Your solution is to compound the lack of realism by just making mmH even more unrealistic. Also, I doubt that the first body that you colonize in that system after the interstellar journey will be Ovin. And it's just a matter of scaling up the lander, as far as I can tell... We still need details on the atmosphere, if there's a sufficient one, dropping lots of equipment will be easy

Yea, because I don't see any reason or good coming from them. They aren't realistic, and they make gameplay trivial, as the calculations here for Ovin show, even after they made Ovin unrealistic in terms of density, and a very improbable size relative to Kerbin. The only way to salvage them is to make them and other things unrealistic too. It's not taking things in a good direction

Assuming mmH engines give a similar TWR to chemical ones (they should), let's just take a 20:1 TWR on kerbin, that 5:1 on Ovin. Suppose you can get a 4:1 mass fraction in a single stage with sufficient TWR. mmH diluted with water should yield 540 Isp, at a 4:1 mass fraction gives you 7, 340 m/s of dV. mmH engines look like they should be able to SSTO from Ovin, maybe you need 2 stages... Not a big problem. If the atmosphere is thin enough that you can use the vacuum version with 1700 Isp, we're looking at a dV of 23,000 m/s. One could probably combine both engines (switching to the magnetic confinement as soon as the atmosphere is thin enough), and easily SSTO it. Easily to orbit and back down, with or without atmosphere (without= all done at 1700 Isp, with: chutes for landing, water injection for liftoff, before switching to the vacuum mmH engines). You'll have this tech before going interstellar, from what they've said, so I wouldn't worry about landing here.

It's been said that it is mid-level tech, that comes after chemical, but before interstellar drives. Aside from making a big boom if the tank is ruptured, we should be able to guess the drawbacks... Like we can with fission/fusion/antimatter/nuclear pulse propulsion/air augmented rockets, etc If they introduce some arbitrary drawbacks, and make the engine based even less on actual science, that's not a good thing... and KSP2 is moving even further in what I view as the wrong direction. I'm still waiting for more info, I did very much like the NERV-US engine concept, and I viewed that as a step in the right direction.

Yea... I'd rather have it be a proper titan analogue. It's clearly in there for gameplay. I figured if we had other star systems, something like laythe could be an exoplanet, but with KSP 1's single system, they didn't have any real good place to put it. It still irks me a little Eve also irks me a little. 1.7g for 7/6 the radius ... What's its explanation for being so dense? The gameplay challenge, clearly. Ovin cranks this up to 11, most likely because of f engines that I don't think belong, so I worry it's one unrealistic thing begetting another.

Stripping it of its lighter elements is relative (super thick 90% hydrogen+Helium atmosphere like Uranus and Neptune, vs something more like 50% and an atmosphere "only" like Venus), there's still CO2 outgassing (also He4 outgassing from radioactive elements), and presumably water. I would expect at a minimum a water world. Also note that planets migrate based on interactions mainly with the gas disk, so if its still migrating out, it should still be picking up a substantial atmosphere (even if it doesn't grow to Jupiter mass) I also expect that, given the rings and what they have talked about in earlier videos, that this represents a very young planet. If that is the case, then I question if there is time for the stripping and migration. Well, that's what is believed to have stunted Mars' formation and left it a runt, but if we assume a Kerbin-Earth equivalence for comparing planets, then this "rocky core" of >10 kerbin masses is about as big as the core that formed jupiter: https://agupubs.onlinelibrary.wiley.com/doi/10.1002/2017GL073160 So if Ovin doesn't exist in a system with something that dwarves jupiter (a Brown Dwarf), this explanation must be rejected. Since volatiles are a tiny percent of terrestrial planet mass, I don't see how this gets to a significantly larger fraction of the mass being an iron core. Gravitational compaction only explains so much... Is that the Kepley 10c that was already discussed and found to be an erroneous estimate? Or is it this? https://www.nationalgeographic.com/science/article/bizarre-planet-largest-known-rocky-world-40-times-as-massive-as-earth Unless Ovin is absolutely baked by the sun and makes Moho look pleasant, I'm not buying it... *Edit* Well, my point is that standard planet formation processes would lead to this rocky core accumulating a massive gas envelope, and becoming a Neptune or Jupiter like world. It's not impossible to have such a core without becoming an ice/gas giant, but it's exceptional. If they don't have something else indicating what caused such an exception, then a 10 kerbin mass terrestrial planet doesn't belong. Even granting a super-kerbin terrestrial world of that mass, I still see no reason that the planet should be 2.5x denser than kerbin. This really strikes me as just there to make a challenge for OP'd engines like mmH engines.

Once mass gets above a certain value, the planet can hold on and accrete helium (MW 3 for the most common isotope in space) and hydrogen (MW 2 for molecular hydrogen). This causes a sharp increase in atmosphere thickness, and a sharp decrease in density as it accumulates mass from low density elements. If ovin was the same density as kerbin, it would be 1.6 G, not 4. It's much denser even though it should not be.

"Mostly", some aren't. The ones shown have mostly been interstellar engines not suitable for landing or even taking off of a body with 1 g surface G. Of the realistic ones we've seen, they have radiation issues (NERV-US) to design around, or will straight up nuke the launchpad/colony (Orion, and similar expected for a torchship drive). They are powerful, but come with unique drawbacks. One very controversial one doesn't, and I fear this planet is a response to that. No, it wouldn't have an ice surface to land on, Neptune doesn't. Its an issue with the name. Ices in this sense reference methane, water, ammonia, etc. Such a world would have a very thick supercritical fluid envelope with no solid surface until perhaps a very hot core, that would be unreachable because of the immense heat and pressure.... Might as well suggest landing on jool. Also, the stats for tis body are nothing like Kepler 10c's.... It's surface G is nowhere near 4 g. Jupiter's isn't either. If it's just a matter of scaling up coefficients to increase dV and TWR to match OP engines, that doesn't interest me. I want to see new, plausible, unique worlds with there own challenges, like the rusk-rald binary with navigation challenges... Something like titan, perhaps a dangerous debris field/rings, contact binary comets, distand kuiper belt like objects, A hypothetical planet 9 analogue with liquid helium/hydrogen oceans, etc. Not just taking a normal planet, and arbitrarily raising g values to make it harder

Yea, and a planet like that wouldn't be fun in KSP. But KSP2 has mmH engines. This is indicating to me that we are seeing severe "power creep", which is generally regarded as bad game design. This is likely the case of one unrealistic thing begetting another. MmH engine makes getting to orbit too easy? Throw in a ridiculous planet that's really hard to get to orbit!!! I'd be fine with a super kerbin of 3-5 kerbin masses.... But 10? Come on, that's ice giant territory, and the best explanation I can imagine for this is that they have some really OP engines and still want a challenge with them.

https://en.m.wikipedia.org/wiki/Kepler-10c "initial observations showed that it has a radius more than double that of earth, and suggested a higher density, suggesting a mainly rocky composition with around 5–20% ices by mass.[5][2][7] for comparison, the earth's oceans represent only 0.02% of our planet's mass,[8] with an additional amount potentially a few times this stored in the mantle.[9] however, in 2017, more careful analysis using both harps and hires data revealed that kepler-10c is not a large terrestrial planet, but instead a typical volatile-rich planet of about seven earth masses." 7 masses, not 17, and an ice giant, not terrestrial. Even the initial estimate would have orders of magnitude more volatiles (proportionately) than Earth.

The overall look of this planet is fine, but I am not fine with a terrestrial planet with 10 kerbin masses. A world of that mass should be like Neptune

Good God, I know gravitational compaction is a thing, but this planet must be over twice as dense as kerbin to have 4G surface gravity.... Seems like this planet is about 10 kerbin masses. It should be a Neptune like world with a massive atmosphere around it, unless it's super close to the sun. This is what I feared with OP tech like mmH engines... to keep things interesting, they just throw in ridiculous stats on planets to make things a challenge again with the OP engines. Just like a RPG where the enemies level up at the same rate you do, and combat remains pretty much the same.

I mean... isn't helping one to wrapping one's head around this sort of thing what KSP excels at? You can do this sort of landing on the flats of minmus to save something like 50-100m/s of dV... Not really worth it other than to do it for the challenge of controlling vertical speed while keeping the craft oriented correctly relative to your horizontal speed, and keeping the craft from flipping as the wheel brakes slowly bring you to a stop.

Fully agree. I'd like to be able to use the lH2 only version in thicker atmospheres, when high TWR isn't needed, such as on something like Titan. I'd also like to be able to maximize vacuum dV even when using the high TWR afterburner mode, such as when landing on Tylo. Well, I think automatic switching would be convenient, like the autoswitching on the rapier... but I can also imagine wanting manual control over it, such as making somewhat shorter vacuum landers: retract the nozzle before touching down. I can see 2 ways this works: 1) a toggle for the nozzle, and a toggle for the afterburner. The first dynamically changes the atmosphere Isp curve for the engine, the 2nd dynamically changes the overall Isp, thrust, and resource consumption (adding O2). I'm not surehow much of a change to the game engine this would require 2) a multimode engine with 4 modes. If I'm not mistaken, already we can have 3+ engine modes in the game code, even if we only have engines with 2 modes (rapier, panther). This would be a little awkward to switch between modes, as you'd have 4 modes to cycle through to get the one that you want. I imagine that mostly during a burn, you'd be going from high TWR and atmo pressure, to low TWR and low atmo pressure, so I'd have the order go: i) Afterburner, nozzle retracted; ii) Afterburner, nozzle extended; iii) No Afterburner, nozzle extended; iv) No Afterburner, nozzle retracted; This would allow easy cycling during a burn from the surface of a planet with an atmosphere. In this case, generally you'd want: 1st, high TWR and the nozzle adapted to a high ambient pressure. 2nd High TWR, but an extended nozzle as the rocket climbs. 3rd low TWR and high Isp as you circularize your orbit. The no afterburner, nozzle retracted case isn't needed. If you want to land on something like Mun, you'd probably not want the afterburner, so you'd go from no burner, extended to no burner, retracted (for touchdown) - this order works again. But it would be inconvenient when you want to land with the burner on, but the nozzle retracted, supposing you come in with burner on and nozzle extended (such as on Tylo), you need to press the cycle button 3 times rapidly to get to the burner+retracted mode for landing. Similarly, taking off from Mun with the mode initially being: no-burner, retracted - if you want to switch to no burner, extended, you'd cut the engine, and have to cycle 3 times to get to the mode you want... So if we can't just have independent toggles for the burner and the nozzle, 4 modes to cycle through would be a bit annoying.

My guess is that time warp can go much higher. The game will still use patched conics, so with no SOI changes, you can calculate a ships poisition and velocity at any time, and thus time warp can be arbitrarily high (calculating positin at time step 10 years take as much cpu as calculating position at a time step of 1 second) for things on simple rails. It will just need to do a bit of extra work for SOI changes, but those can also be calculated precisely without needing time steps (I mean... they are doing things with collisions too to make sure that time-steps don't result in things phasing through each other). That leaves the challenge of thrust on rails. IIRC, that isn't calculated so precisely, and must be done analytically (like an infinite series, the more calculations done, the smaller the error). My guess would be that as soon as the maneuver node planning is done, showing the planned trajectory, that trajectory can be stored, and used to quickly calculate the ships position at an arbitrarily high warp as well. If the calculation can't be done quickly and accurately for the maneuver node, then these long burns are going to have use wildly off course, and it will be a mess. If the calculation can be done quickly and reasonably accurately, then there's already a pre-calculated trajectory, and the game just needs to refer to that each time step during warp. So, I expect drives with less than .1G acceleration (only end game torchship antimatter drives going >1 G), distances about 1/10th scale, and higher time warp limits.

Link to the mod, what does it do?

I would rather have mass drivers and beamed power propulsion. Gotta love massive laser arrays that with a little tweaking turn Mun into the death star....

A photon drive would be either: 1) Antimatter powered: likely going to be in game 2) A solar sail: would be cool 3) A light sail, and some laser installation: ie beamed power propulsion, I would love this (and beamed power need not be limited to light sails) 4) Massively inefficient if powered by anything other than antimatter or solar: (if using a fusion reactor, throw the reactant mass back at high speed for more thrust per unit fuel) Regarding the light/solar sails: Using solar panels instead would be massively inefficient, and would be massively heavy for the miniscule thrust. Photovoltaics would be far less efficient than just reflecting the photon, they would be far heavier, and they would not be able to take nearly the same light intensity... very very very low TWR as a result. magnets do not contain photons

Better have a kerbal on it, and a probe that grants SAS, no? Besides, I want to be able to control probes without a connection (should just be required for data)... real probes can do things on their own without a connection, just as an astronaut can. A probe core should be able to analyze its surroundings, take measurements, and plot a course on its own. Real probes can. Of course, I don't want autopilot, I want to pilot the craft as if I am the probe's AI. Bah, I just set up a simple relay network if that is the case. Avoiding communication blackouts back to Kerbin is easy. I'll want those anyway for science transmission. yea, scientists and engineers are all I really need... and really just scientists, but engineers are nice to speed things up, and the craft modification does make things interesting now.

To be clear, the game seperates thrust and lift, and what you are discussing is lift. Well, real helos do this by cyclic, and we now have cyclic, but I think the blade disk needs to actually tilt. I think that just relies on flexing in the blades. I think KSP 1 already could model this if they had an appropriate control algorithm But real tandom rotors do change the amount of "thrust" on different sides. That is how realistic heli dynamics would work. I think KSP just doesn't know to apply left roll cyclic to the front rotor and rear roll cyclic to the rear rotor. I get around this by using quad copters, or hinged rotors.

I doubt that we will see anything other than 1 "real" terrain surface. That doesn't mean that you can't have cave "objects", as we saw to a limited extent in the Tylo cave, and sort of with the Mun arches (I believe you can find some colonies hanging from those in Youtube videos). The Arma series also has terrain with just a single heightmap (thus one "real" terrain surface), but there are small caves in the official maps that are composed of walkable objects such as boulders. (similarly, it also supports bridge objects that can be driven over, and the Ai can osrt of handle it). Then there a number of user made maps where they just assign a very low elevation to a place (ie, make a pit), and fill it with a 3D cave/bunker object. If KSP1 had the Tylo cave, I expect KSP2 to have some sort of Cave object - but I expect them to be limited in size and number, and sort of be easter eggs.

It seems that there's at least one prediction that was pretty accurate...

I don't disagree with any of that, I am just saying, it seems strange to express concern that this LANTR engine makes getting to orbit too easy, given what has already been shown... In particular the mmH engine, as it has none of the radiation drawbacks (aside from the torch ship drive and the Orion drives, it seems likely other interstellar drives will be put on craft that must be built in space - and the Orion must have some other engine for the initial liftoff, or you destroy the colony)