Will other star systems be scaled up?

[Tux1]

It was already noted that the closest star in KSP 2 is 4 light-years away, and not say, 0.4 light years. And that has me wondering, does that imply that other star systems will be more realistically scaled? It would certainly be interesting, and it lines up with another thing we know about KSP 2, that being places further away are more difficult to navigate. Having increasingly realistic scales as you get further away from Kerbol would indeed contribute to that difficulty curve. It also seems like a great lore opportunity, like maybe some kind of stellar effect has lead to a region of space having denser matter than usual.

Edited December 14, 2022 by Tux1

[Guest]

I don't think so. At the end of the day, while it's perfectly doable to create an Earth-capable launcher from vanilla KSP1 parts, not only will the mass fraction to orbit be incredibly small the vast majority of players will either not bother or simply install "realism" mods to bring the parts up to a more reasonable mass fraction.

[Tux1]

Keep in mind that the level of technology seen in KSP 2 is much, much higher than in the original. It's likely we'll be able to unlock some kind of extremely efficient nuclear engine that can carry a payload into the orbit of a realistically sized body with the same mass fraction as primitive ones on Kerbin.

Edited December 14, 2022 by Tux1

[Guest]

6 minutes ago, Tux1 said:

Keep in mind that the level of technology seen in KSP 2 is much, much higher than in the original. It's likely we'll be able to unlock some kind of extremely efficient nuclear engine that can carry a payload into the orbit of a realistically sized body with the same mass fraction as primitive ones on Kerbin.

Even with advanced engines the dry/wet mass ratio of vanilla KSP parts are ridiculous compared to their IRL counterparts. That means the mass fraction to orbit will still be rather pitiful. Players will have to construct ever larger, more ridiculous ships to even get into orbit, stuff that won't fit into the VAB (the entire reason we are going to get orbital constructions yards). And for that matter, orbital yards will be a thing so the "difficulty" really isn't. Lastly, if the tech scales with the planets then there's no real "difficulty" associated with going to a bigger star system.

[pandaman]

I don't think other systems will be 'scaled up' as such.  But I expect  sizes etc. will be different to present different challenges.

[TLTay]

Oops. I read the first line as "closest star in KSP2 is 4 years away."

I sure hope the EA updates don't take that long...

[Drakenred65]

Adding in a real scale fictional version of our solar system could be interesting. Or some of the exoplanets we have found. Granted some are still not exactly confirmed lol.

[K^2]

2 hours ago, [email protected] said:

Adding in a real scale fictional version of our solar system could be interesting. Or some of the exoplanets we have found. Granted some are still not exactly confirmed lol.

Taking Sol verbatim would be a lot of work for just an Easter egg and would stick out a little too much if it's prominently placed among the other systems. I think a known exoplanetary system is a more interesting idea. The only problem is that our ability to detect exoplanets is kind of weak, so all these star systems look very barren in comparison to Sol. It's likely that many of them are filled with many more small planets and other objects, plus moon systems around the known planets, but we can't detect these things to make an accurate maps of them. However, astronomers have gotten pretty good at making simulations of star system formation that closely match the known features of a system so that the resulting simulation can be studied in far more details. Naturally, Sol is the main target of such research, but I'm sure there are simulations of other star systems. So if we wanted to have a system in KSP that's pretty much "This is a real system, best we can tell," I'd take a simulation of one of these star systems with known exoplanets and use it to fill in the gaps.

[MechBFP]

The problem with realistic scales similar to our solar system is that they can be very boring. It takes 10 minutes to get to orbit for Earth compared to like 2 minutes for Kerbin. 

I suspect for gameplay reasons they will stick to similarly sized systems. 

[Skorj]

On 12/14/2022 at 1:06 PM, regex said:

Even with advanced engines the dry/wet mass ratio of vanilla KSP parts are ridiculous compared to their IRL counterparts.

Pardon my pedantry, but that's not strictly true, though you have to read part descriptions closely to see why.  At first glance it would seem that the "empty can" to hold 8 tons of fuel masses 1 ton - after all, that's the part mass, right?  But the can is not a ridiculous 12.5% of the fuel it carries, not even Kerbal engineering is that bad; it's a much more reasonable 2.5%.  The other 10% is residual fuel.  Every rocket engine (IIRC) has the same note in its "propellant" stats: stops at 10% fuel.

This is one of the coolest bits of realism in KSP, and one that is just ... hidden.  Hidden to the point that I wonder if the KSP2 devs are even aware of its purpose.  I'm not sure how that 10% value compares to real rockets, because I can't find anything published anywhere about it.  But in  one of his recent interviews with Tim Dodd, Elon Musk mentioned that residual fuel was the biggest chunk of mass that Falcon 9 lands with, so it's not small.  Given that 10% is likely a number from the early KSP days, I suspect it's probably in the right ballpark for Mercury to Apollo era rockets and tank design.

I'd love to hear from an expert on this aspect of rockets.  I just find it very interesting that this is apparently the biggest target for efficiency improvements in modern rockets, but no one seems to be talking about it (at least in public).

[Guest]

11 hours ago, Skorj said:

But the can is not a ridiculous 12.5% of the fuel it carries, not even Kerbal engineering is that bad;

Kerbal engineering is that bad, but not because of "realism". The reason is to make you work for putting mass on orbit because you need an orbital velocity around ~2,300m/s in LKO. That's paltry compared to the ~7,500m/s required for LEO.

11 hours ago, Skorj said:

But in  one of his recent interviews with Tim Dodd, Elon Musk mentioned that residual fuel was the biggest chunk of mass that Falcon 9 lands with, so it's not small.

Falcon returns with residual fuel because it uses it for landing, and probably carries a bit extra to account for errors.

11 hours ago, Skorj said:

Given that 10% is likely a number from the early KSP days, I suspect it's probably in the right ballpark for Mercury to Apollo era rockets and tank design.

I would love to see a citation for your speculation here aside from what's a pretty obvious reason to keep residual fuel around. If unburnt fuel was a major issue in cutting efficiency (to be sure, you will get some unburnt fuel, but the idea is to not have any at all) for "traditional" disposable launch vehicles you'd be hearing about it, especially since here on Earth we're usually dealing with <5% mass ratio to LEO.

Edited December 16, 2022 by regex

[Skorj]

On 12/16/2022 at 11:44 AM, regex said:

Kerbal engineering is that bad, but not because of "realism". The reason is to make you work for putting mass on orbit because you need an orbital velocity around ~2,300m/s in LKO. That's paltry compared to the ~7,500m/s required for LEO.

Falcon returns with residual fuel because it uses it for landing, and probably carries a bit extra to account for errors.

I would love to see a citation for your speculation here aside from what's a pretty obvious reason to keep residual fuel around. If unburnt fuel was a major issue in cutting efficiency (to be sure, you will get some unburnt fuel, but the idea is to not have any at all) for "traditional" disposable launch vehicles you'd be hearing about it, especially since here on Earth we're usually dealing with <5% mass ratio to LEO.

I'm not sure we can know the motivations of the original dev team for the 12.5%, probably you're right, but we do know the in-game explanation: the "stops at 10%" is what we're told by the parts descriptions in the game.  The 10% is canon.

In context Elon was talking about an engineering challenge - the fuel that can't be pumped out of the tank, distinct from the re-entry and landing burns.  The fuel pumps can't tolerate cavitation, so you can't have any bubbles in the fuel/oxidizer coming into the pump.  For example, you can't have a vortex deep enough that "air" is introduced into the flow, as happens when a sink drains.  Of course there's lots of engineering around this, as with every part.

I'd love to know what the real world %s are, but I can't find them.  I've looked through the F-1 technical manual and operating instructions books, but it doesn't seem to be there (no surprise, since it's a property of the fuel tank not the engine).  I can't find a searchable PDF of either, though. 

[DrCHIVES]

If I remember correctly, Ovin was pitched to us as a super kerbin world 60% larger and 4x the gravity of kerbin.  I'm assuming they pitched this as a "wow factor".  The new boss to replace Eve so to speak.  Given that Kerbin is roughly the size of the moon irl and Jool is roughly the size of Earth, I don't think this theory of more realistic scale planets in other star systems will be a thing as Ovin would still be considered a relatively average to small planet irl.  However with the implementation of interstellar, 3 body soi physics, and axial tilt.  It will be very exciting to see realism overhaul make its way into ksp2 as well as what would now be possible with real solar system expanded to include the local interstellar cloud.

[Drakenred65]

Even at that it’s still smaller than Earth

one second

Earth  6371 km

Kerbin 600 km

Ovin 960 km

earths moon  1737 km

 

so it’s still smaller than our moon.

 

Edited December 19, 2022 by [email protected]

[Leganeski]

On 12/14/2022 at 10:40 AM, Tux1 said:

It was already noted that the closest star in KSP 2 is 4 light-years away, and not say, 0.4 light years.

Does this mean the speed of light times four Earth years, or times four Kerbin years? I don't know enough to say either way, but four light⁠-⁠Kerbin⁠-⁠years ("only" 11.0 Pm, compared to Proxima Centauri's distance from the Sun of 40.2 Pm) would fit in better with the Kerbal scale.

[tstein]

9 hours ago, Leganeski said:

Does this mean the speed of light times four Earth years, or times four Kerbin years? I don't know enough to say either way, but four light⁠-⁠Kerbin⁠-⁠years ("only" 11.0 Pm, compared to Proxima Centauri's distance from the Sun of 40.2 Pm) would fit in better with the Kerbal scale.

That  brought me the mental Idea of how kerbals would  solve  traveling to a start 4 ly away. They would put rockets in kerbin and push its orbit down so it orbited the sun in 50 days...  problem solved  suddenly 4 Ly is not that far.

[shdwlrd]

11 hours ago, Leganeski said:

Does this mean the speed of light times four Earth years, or times four Kerbin years? I don't know enough to say either way, but four light⁠-⁠Kerbin⁠-⁠years ("only" 11.0 Pm, compared to Proxima Centauri's distance from the Sun of 40.2 Pm) would fit in better with the Kerbal scale.

Considering that 1ly for Kerbin equals 106.5 ly days for Earth. If real distances are used, then, for example, Proxima Centauri would be a little more than 12 ly for the Kerbal scale. It would make sense to do some scaling of the distances, but not to the extreme of the typical scaling used in KSP. Maybe scale the distances by 1/3 or 1/2?

[Leganeski]

16 minutes ago, shdwlrd said:

Maybe scale the distances by 1/3 or 1/2?

Yes; that is what I was describing. A Kerbin year is 3.43 times shorter than an Earth year, so using light-Kerbin-years would place the systems at 1/3.43 times the real-scale distance, rather than the full 1/10 or 1/11 found within the Kerbol system.

[shdwlrd]

51 minutes ago, Leganeski said:

Yes; that is what I was describing. A Kerbin year is 3.43 times shorter than an Earth year, so using light-Kerbin-years would place the systems at 1/3.43 times the real-scale distance, rather than the full 1/10 or 1/11 found within the Kerbol system.

I figured that. Just had to add some clean numbers for it to make sense. (For me at least. ) I don't know what would be the best solution. Keep the real scale distances between the stars and potentially scare off players from going interstellar. Or you can say the Kerbol system is in an area where the star density is much higher, so the stars can be closer.