Show and Tell - Ovin

[TLTay]

26 minutes ago, Nirgal said:

I'm also quite worried about the graphical 'cutting' on the terrain, we've seen this on previous world teasers and it looks to be getting worse if anything. I hope I'm misguided and this is just caused by the footage being sourced from a test scene, and not real gameplay.

Do you mean the shapes of the cliffs and stuff changing as the camera gets closer/farther away?

[KerikBalm]

4 hours ago, t_v said:

The engine technologies being added in this game are mostly based on real-life science, which means that some of them will be, understandably, overpowered.

"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.

4 hours ago, t_v said:

 Ice giants like Kepler-10c which would still have a surface to land on, even if it was ice instead of rock

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.

4 hours ago, t_v said:

So I'm glad that these planets are hard, because otherwise the end game technology would simply be too overpowered compared to the challenges of the game. 

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 

[TheOrbitalMechanic]

I feel like Ovin will be a relative outlier with its high-gs; they have said they want to introduce planets that have unique challenges (like Rask and Rusk, or one that is somehow supposed to require a spaceplane to land on) instead of just having every planet be bigger. A few large and high-g planets like Ovin sprinkled in probably won't hurt anything too much, but I agree it would be dumb if "bigger planet" was the only problem to solve from mission to mission.

[Mr.Evil]

So, I don't think they show us the best and most curious celestial bodies. It's cooler to see them ingame (hopefully soon). ^^

[Synonym Toast Crunch]

3 hours ago, KerikBalm said:

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,

Not just taking a normal planet, and arbitrarily raising g values to make it harder 

Why is a super earth so implausible to you? Is there a reason that a rocky planet with a large mass couldn't exist in real life?

[K^2]

On 10/15/2021 at 9:03 AM, Jaylr234 said:

ovin will be really hard to get off of

i am not ready for this

You have to land on it without crashing first. At 4G, unless the atmosphere is as thick as Eve's, parachutes aren't going to do much good. And I strongly expect it to have a very weak atmosphere based on the images. That planet is going to be a graveyard of broken ships.

[KerikBalm]

6 hours ago, Synonym Toast Crunch said:

Is there a reason that a rocky planet with a large mass couldn't exist in real life?

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.

[K^2]

8 hours ago, KerikBalm said:

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.

There are several processes that can strip planet of lighter elements and prevent it from accumulating helium. Two most likely are spending a lot of time very close to the primary and then migrating out to its current location, potentially by redirecting another planet into the star in the process, or a close encounter with a gas giant early in the formation. Both of these can result in a planet that's basically a core of a gas giant with a thin crust of rocky material on top and an insubstantial atmosphere for that heavy of a planet. Since a larger fraction of the planet's mass is due to its larger iron core, the average density is also a lot higher.

There was a bit of a discussion of an exoplanet candidate with similar apparent characteristics a while back. Though, perhaps, still not quite as dense as Ovin, it shows that such events happen in star system formation.

[Admiral Fluffy]

Goodness. I hope it doesn’t have an atmosphere!

[KerikBalm]

3 hours ago, K^2 said:

There are several processes that can strip planet of lighter elements and prevent it from accumulating helium. Two most likely are spending a lot of time very close to the primary and then migrating out to its current location,

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.

3 hours ago, K^2 said:

a close encounter with a gas giant early in the formation.

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.

3 hours ago, K^2 said:

Both of these can result in a planet that's basically a core of a gas giant with a thin crust of rocky material on top and an insubstantial atmosphere for that heavy of a planet. Since a larger fraction of the planet's mass is due to its larger iron core, the average density is also a lot higher.

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...

3 hours ago, K^2 said:

There was a bit of a discussion of an exoplanet candidate with similar apparent characteristics a while back. 

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.

Edited October 18, 2021 by KerikBalm

[klesh]

On 10/16/2021 at 2:33 PM, The Doodling Astronaut said:

Huh, interesting.  I feel like the 2020 version looks better.

[K^2]

12 hours ago, KerikBalm said:

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.

You can start losing surprisingly heavy elements if you dip close enough to the star early enough in the formation through combination of heat and gravity. I'll grant you that a planet in that situation is on its last legs before being swallowed outright, and it would take a miraculously well-timed boost from something else falling into the star, but out of all the stars in all the galaxies...

12 hours ago, KerikBalm said:

So if Ovin doesn't exist in a system with something that dwarves jupiter (a Brown Dwarf), this explanation must be rejected.

Unless that something else got ejected or absorbed into the primary. Again, we have no idea what sort of dynamics that system could have been going through before settling down. Merging binary star system, for example, can produce an absolutely wild distribution of planets and compositions which will otherwise will look tame and normal a few billion years after the stars merged.

I wouldn't expect to encounter these kinds of system very often, but if we give developers a fiat of picking an interesting system to exemplify in the game, none of this goes outside plausible.

12 hours ago, KerikBalm said:

It's not impossible to have such a core without becoming an ice/gas giant, but it's exceptional.

I don't disagree. And it'd be nice to get a nod to that somewhere in the game, pointing out how bizarre it is for a planet to have these properties.

12 hours ago, KerikBalm said:

This really strikes me as just there to make a challenge for OP'd engines like mmH engines.

I mean, obviously that's why developers want it in the game. I just don't think it's a bad reason to put a  planet like that in the game, so long as it merely stretches the limits of what's physically possible for a real world, after the 10x scale correction, of course. If it was just absolutely impossible, I would be against it too. Merely very, very, unlikely is acceptable if it's in the name of good gameplay and interesting place to explore.

I mean, if we start getting technical about it, Lathe is already a good example of a world that's exceptionally unlikely to happen. But it's a fun moon to have in the game and I'm glad it's there.

[Pthigrivi]

Love this conversation, lots of cool science. Still like is there a plausible chemical explanation for why Jool is bright green? Some things can just be for fun. Though in general I agree it's all more interesting if as we're playing we learn some things about how these worlds are formed. 

Edited October 19, 2021 by Pthigrivi

[KerikBalm]

1 hour ago, K^2 said:

I mean, if we start getting technical about it, Lathe is already a good example of a world that's exceptionally unlikely to happen. But it's a fun moon to have in the game and I'm glad it's there.

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.

[Delay]

4 hours ago, KerikBalm said:

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.

Eve's atmosphere should be much denser and thinner considering its gravitational influence. But I'd rather have to fight a 90km atmosphere for a ridiculously cruel challenge than be mildly worried by a 30km excuse for one that tanks my engines only at sea level (it's not like terminal velocity would be the main limiting factor).

Edited October 19, 2021 by Delay

[magnemoe]

Question on the surface will reflection from the ring light up the surface? The thing is close and could fill huge part of the sky. 

[AtomicTech]

See this!

 

It's great news!

 

[OHara]

On 10/19/2021 at 1:49 PM, magnemoe said:

will reflection from the ring light up the surface?

There is reason to hope so, given that we have seen lighting on the dark sides of bodies consistent with moon-shine and planet-shine.  I think this was mentioned in the interview here (only useful if you understand spoken American English) I'll see if I can find or remember a timestamp. [Edit: A better source about secondary lighting is the earlier show and tell video here.]

 

On 10/17/2021 at 11:24 PM, Synonym Toast Crunch said:

Is there a reason that a rocky planet with a large mass couldn't exist in real life?

KSP 1 already adjusted the gravitational attraction of planets (relative to real planets/moons of similar size).  That lets us have a 1-G surface but still get to orbit in 1/3 the time it would take to reach Earth orbit (for a given G-force on the kerbonauts) so I appreciate that change for the sake of making a good game.

If I imagine that the game designers imagined a different gravitational constant G, I can see how the planets line up with their analogues.  (KSP wiki says planets are 10× typical density, but KSP 1 only needed to define the product G×M of each planet, so alternatively they could have imagined a larger G in the Kerbal universe.   Distribution of density, between core and shell, happens to not matter for surface g or orbital velocity, so we can figure surface g simply from G×density×R×4π/3)

     G = 0.067 km³/kg/s   Saturn  Europa    Moon   Ceres  Triton   Pluto  Phobos    Mars Mercury Ganymede  Earth   Venus
                density     0.70    3.03    3.35    2.16    2.06    1.85    1.88    3.94    5.43    1.94    5.52    5.24 g/cm³
                 radius    60268    1561    1737     473    1353    1188      11    3396    2441    2634    6378    6052 km
              surface g    11.79    1.32    1.63    0.29    0.78    0.62    0.01    3.74    3.71    1.43    9.84    8.87 m/s²
            low orbit v    26661    1437    1681     368    1027     855       8    3564    3008    1938    7923    7325 m/s


G(KSP) = 0.700 km³/kg/s     Jool   Eeloo     Mun  Minmus    Dres     Ike     Pol    Duna    Moho  Laythe  Kerbin     Eve            Ovin consistent
                density     0.45    2.74    2.78    2.79    2.79    2.89    2.89    3.13    3.68    5.35    5.58    8.14 g/cm³     13.94    8.53
                 radius     6000     210     200      60     138     130      44     320     250     500     600     700 km          960    1200
              surface g     7.85    1.69    1.63    0.49    1.13    1.10    0.37    2.94    2.70    7.85    9.81   16.70 m/s²      39.25   30.00
            low orbit v     6863     596     571     172     395     378     128     970     822    1981    2426    3419 m/s        6138    6000

Gas giants have mean densities about the half that of water,  rocky moons about that of silicates, and iron-core planets near that of iron.

Ovin is a moderate outlier even in the KSP universe as defined in KSP1.

Maybe they are trying to be consistent with the rings being relatively large compared to the planet.  The Roche radius, inside which gravity rips apart moons, is usually about 2.5 times the radius of the planet, but if the planet is more dense than the moons, the Roche radius is relatively larger.  Maybe they took the restricted-3-body gravity simulation they made for Rask and Rusk, applied it to all planets, and are playtesting to see if that is fun or frustrating.  If they do that then players would notice the Roche radius, because gravity of a planet would noticeably compete with gravity on a moon that is close to the Roche radius.
[Edit: The preview about Gurdamma also shows large rings, and mentions a moon in their gap, presumably metallic moon, so probably they are being more flexible about where moons and rings can go than the simple single Roche limit common to all satellites.
[Edit Edit: A later KSP 2 video describes Gurdamma has having a recent collision that formed a ring, that is in the process of coalescing into a moon.  So that ring is probably rocky, being formed from crust, and it is a large-diameter ring, consistent with it being high enough that clumps of rocks held by their own gravity could survive tidal effects.]]

Edited October 29, 2021 by OHara
found earlier show-and-tell mentioning planetshine, and a moon in a ring-gap

[Admiral Fluffy]

On 10/17/2021 at 12:37 PM, KerikBalm said:

One very controversial one doesn't

What one?

[The Aziz]

13 minutes ago, Admiral Fluffy said:

What one?

Metallic hydrogen engine, obviously. 

Someone forgot how gigantic is the refinery for that fuel, and that it is most likely one of the endgame items, same as Ovin, being the largest body with a solid surface. Thus, an achievement even with endgame engines. A final frontier, I may say? Just because we don't know the drawbacks now, doesn't mean there aren't any.

Just because the Vector engine is super powerful and small at the same time, doesn't mean I'm going to use it on my 1.25m rockets.

Edited October 19, 2021 by The Aziz

[KerikBalm]

35 minutes ago, The Aziz said:

that it is most likely one of the endgame items,

It's been said that it is mid-level tech, that comes after chemical, but before interstellar drives.

35 minutes ago, The Aziz said:

Just because we don't know the drawbacks now, doesn't mean there aren't any.

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.

[starcaptain]

On 10/15/2021 at 9:01 AM, AtomicTech said:

So this is the new Tylo...

You do realise that Ovin will win the vast  majority of the time, right? It's like picking a fight with a wall.

[AtomicTech]

12 minutes ago, starcaptain said:

You do realise that Ovin will win the vast  majority of the time, right? It's like picking a fight with a wall.

 

[shdwlrd]

45 minutes ago, starcaptain said:

You do realise that Ovin will win the vast  majority of the time, right? It's like picking a fight with a wall.

That's what sledgehammers are good for. 

[KerikBalm]

On 10/15/2021 at 11:14 PM, SAMCG14 said:

To get into a 140km orbit without taking into account air and gravity drag it gives me 6 130 m/s of Delta-V with 5 730 m/s of orbital velocity

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.