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The Kerbolar System should be resized. (Or: Another excuse for me to make a list!)


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In the past few months I've been a bit vocal about not wanting the Kerbolar System to be rescaled.(Mostly just whenever people insist that it should be) However, after some time,I thought about it today, and I think Kerbin should be rescaled after all. Before we get into the specifics of it, here's a List! (Bear with me!) EDIT: Attempted to fix the horridly tired and incorrect mathematics.

Real Earth

Gravity: 9.81 m/s^2

Radius: 6,371 km

Scale: 100%

Atmosphere Height: 120 km

Approximate ÃŽâ€v to Orbit just above the atmosphere: 10 km/s

notes: These values are an ideal Earth, a perfect sphere.

Stock Kerbin

Gravity: 9.81 m/s^2

Radius: 600 km

Scale: 9.4176... %

AtmosHeight: 70 km

ÃŽâ€v to Orbit: 4.5 km/s; 3.5 km/s using FAR/NEAR

notes: People assume that Kerbin is 10 times smaller than Earth. In fact, Earth is actually a very slightly less than 11 times bigger than Kerbin. This means very slightly more than 9% scale. In an interview with NovaSilisko (the developer who created most of the planets (aside from Kerbin, Mun, and Minmus), He said that the Kerbal universe has higher gravity than our universe, so the planets are not actually superdense.

Smearth

Gravity: 9.81 m/s^2 (presumably)

Radius: 637 km

Scale: 10%

AtmosHeight: 70 km

ÃŽâ€v to Orbit: 3.5 km/s (presumably)

notes: There's a lot of guesswork surrounding Smearth.

Real-Scale Kerbin

Gravity: 9.81 m/s^2

Radius: 6000 km

Scale: 94.17673... %

AtmosHeight: 120 km

ÃŽâ€v to Orbit: 10 km/s

notes: "Real Scale" Kerbin is actually smaller than Real-Scale Earth.

6.4:1 Scale Kerbin

Gravity: 9.81 m/s^2

Radius: 3,840 km

Scale: 60.2731... %

AtmosHeight: 91 km

ÃŽâ€v to Orbit: 7.2 km/s

notes: This is the least rounded number of the bunch! Why would you want this number at all?

... I'll tell you why. Kerbal parts are scaled to around 64% of their real life counterparts. The Mk1-2 Command Pod (2.5m) is based on the Apollo Command/Service Module (3.9m) 3.9 times 0.64 is 2.496, which is rounded to 2.5m (as the diameter of parts already varies by this much anyway.)

Why does Kerbin need a rescale? Realistic Aerodynamics is a planned feature, and obviously that means getting rid of soupy atmosphere. The problem with this is that you've removed almost 1 km/s ÃŽâ€v. This makes a problem already faced in stock even worse, the scales of the rockets. You have tiny little rockets attached to your payload, and it just doesn't look like it has the right amount of fuel! It looks WAY too small. In stock, this is just noticeable as a slight imbalance in the rocket's size vs what the rocket can do. (You can get away with SSTO rockets that look like Mercury-Redstone)

If you set the Kerbolar system to 64% of current scale, the universe and the spaceships fit into the same real-life equivalent scale as each other, whilst still allowing Kerbals to use smaller ships to accommodate their smaller size.

To facilitate this change a few things would have to change/be added. The hypothetical changelog goes as the following:

Kerbal Space Program: Jumbo 64 (0.30.0) is released!

Large New Features

-The Aerodynamics System has been completely overhauled.

--Shape-based Aerodynamics (Wider constructions are less aerodynamic)

--Wing Effects (Authentically adjusts wing lift and drag based on position and configuration)

--Stall (Planes can now stall out)

--Body Lift (Previously the Mk2 and Mk3 Fuselage system worked using the winglet code, not anymore. All parts experience the Lifting Body Effect)

--Rentry Shock Heating and Mach Effects (Take care when planning your return, because you might otherwise become quite toasty! This can be disabled in difficulty settings and is off by default on Easy mode)

--Fairings (To make rockets more aerodynamic, a new fairing system has been devised)

-All celestial bodies have been rescaled.

--Planets and Moons are now 6.4 times larger than they were before.

--Atmospheres have been scaled to 1.32 times larger. Kerbin's atmosphere extends to 91 km.

--Planet sizes can be switched to classic mode in difficulty settings, and are default for easy mode.

--The Kerbal Universe scale now approximately matches the Kerbal Spacecraft scale. (Around 64% real life.)

--Planet and Moon textures/terrain are now 6.4 times higher definition.

---Much more procedural craters.

-Jet Engines have been totally reworked.

--Intake Air is no longer used as a reaction mass.

--Jet Engine Fuselages hold the interior components for each type of Jet Engine. This means different fuselages for the RAPIER, the Basic Jet Engine, and the TurboJet Engine.

--What previously functioned as the engine itself is now a nozzle. Each nozzle has different functions. Basic Jet Nozzle has minimal thrust vectoring, and an afterburner. Vectored Jet Nozzle has no afterburner, but more thrust vectoring capabilities, as well as higher efficiency in the upper atmosphere. The RAPIER Quad-Nozzle can function as a cruddy rocket engine on it's own, but when added to the RAPIER fuselage it functions as a dual-purpose engine.

--Air Intakes now must be directly attached to an Engine Fuselage or a Tank that connects directly to an Engine Fuselage.

--There's also new SCRAMjets, which function best at very high speed.

Changes

-Dry Masses of all tanks have been decreased.

-All liquid-fueled engines have been redesigned to remove "tankbutts." (The mounting points which include the end of the fuel tanks)

-Isp now affects thrust instead of fuel flow rate, and now also follows a curve down to lower efficiency at higher atmospheric pressure. (Eve Ascents are now VERY hard)

-All Liquid-Fueled Engines have been rebalanced, and many of them have higher thrusts.

-There are now new 5-meter fuel tanks and other parts. They are absolutely MASSIVE.

-Reaction Wheels have been nerfed. They are all half as powerful.

-RCS Thrusters have been buffed. They are now 1.5 times as powerful.

-Rebalanced most of the tech tree.

--Movable winglets are now closer to the beginning of the tech tree.

--Stayputnik Mk1 is now moved to the Basic Rocketry node, and has a more powerful battery.

-There are more timewarp settings.

--Timewarp altitudes have been changed.

Edited by GregroxMun
Attempting to fix math.
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The chief drawback of enlarged celestials remains more time-consuming launches to orbit. I recall ferram experimenting and something like a doubling of Kerbin's size suffices to restore delta-v needs to 5 km/s or so, which is enough.

Also, a single release is never going to have all those changes.

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-Isp now affects thrust instead of fuel flow rate, and now also follows a curve down to lower efficiency at higher atmospheric pressure. (Eve Ascents are now VERY hard)

I'd actualy expect impossible would be a more apropreate term. Asumeing eve scaled up just like kerbin I'd expect its dV to orbit to rise as well. Eve ascents are already walking a razer edge between dV and TWR and are frequently huge constructions. If the dV and required thrust both go up I'm not sure you could get a ship out of there. Anything sufficently powerful to escape eve would probably be too massive to launch effectively from kerbin unless you could SSTO without stageing and then refuel in orbit before sending off to eve.

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Nothing's too massive to launch from Kerbin. Some things just take more patience and work than others.

And of course new parts could be added. Ie engines optimised for Eve surface pressure. (Heck, the aerospike arguably is already.)

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I'd actualy expect impossible would be a more apropreate term. Asumeing eve scaled up just like kerbin I'd expect its dV to orbit to rise as well. Eve ascents are already walking a razer edge between dV and TWR and are frequently huge constructions. If the dV and required thrust both go up I'm not sure you could get a ship out of there. Anything sufficently powerful to escape eve would probably be too massive to launch effectively from kerbin unless you could SSTO without stageing and then refuel in orbit before sending off to eve.

There's nothing mathematical preventing orbit from being achieved around Eve. Aerospike Engines would be the best bet for launching from Eve. I'd hazard a wild guess and say that you'd need a rocket the size of one of the larger Novas to launch a lander can into orbit.

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It's worth noting that a 6.4x Kerbin launch with FAR will probably take about the same amount of time as a current soupodynamics launch. People really underestimate how *long* it takes to go up 10 kilometers at 1-200m/s.

Also, how is 6371km smaller than 6000km? ;)

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--Jet Engine Fuselages hold the interior components for each type of Jet Engine. This means different fuselages for the RAPIER, the Basic Jet Engine, and the TurboJet Engine.

--What previously functioned as the engine itself is now a nozzle. Each nozzle has different functions. Basic Jet Nozzle has minimal thrust vectoring, and an afterburner. Vectored Jet Nozzle has no afterburner, but more thrust vectoring capabilities, as well as higher efficiency in the upper atmosphere. The RAPIER Quad-Nozzle can function as a cruddy rocket engine on it's own, but when added to the RAPIER fuselage it functions as a dual-purpose engine.

-All liquid-fueled engines have been redesigned to remove "tankbutts." (The mounting points which include the end of the fuel tanks)

.

Not sure I understand the point of these. Otherwise some decent ideas that seem like far too big of an overhaul and almost certainly wont happen. Here's hoping for KSP 2!

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...and how would this be beneficial to gameplay?

It would facilitate the removal of the souposphere. For example, a few days ago I installed NEAR and launched a simple small rocket on a new career save. I immediately quit and downloaded Real Solar System for that save-- it was so much easier to leave the atmosphere with it being realistic at its scale that more of a challenge was needed. If Squad ever wants to add a realistic atmosphere, they will need to either extend it stupidly further into space to make its density near the ground closer to some form of reality, or, preferably, make it less dense and more logical. Since decreasing the density is too easy, the bodies should be made larger up in response, and to keep the scale of parts consistent as a bonus.

Besides the size of the planets, his suggestions combine features of several of the most popular mods, which is feasible due to the new diffculty slider. He has some rebalances that may or may not turn out well.

The one thing that might be iffy, more than the radically changed aerodynamics is the change in ISP, which could be a bit of a shock to veterans. Having different thrust/fuel unit as density changes would take a little getting used to. A mod should probably be made to test the viability of this, if there isn't one already; it sounds interesting.

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Pretty sure the devs have said ISP will not change with tank density--the current system is an approximation but it works well enough. I don't know about rescaling Kerbin though, as others have said the increased launch times would be a pain. I already use MechJeb for easy launches, while harder launches (code for I don't want to rendezvous several separate launches to build a ship in orbit) already take a long time if you use the old trick involving spikes and a bajillion intakes, which I'm not sure OP's suggestions fix either.

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I rly want to get a better aerodynamics model to begin with (already playing with far and smiling, thinking what cruel things I did to physics before :P)

DRE as a difficulty settings, yes please.

Rescaled kerbin, nope. I am more or less happy with the current balance of isp, thrust and masses which are adapted to the size.

Kerbins size is not realistic but as a tribute to the learning courve and gameplay I am happy with that. And btw those loooong ascents to orbit in RSS/RO (which I like and play regulary) can be anoying from time to time, especially if you want to test a new craft and realise you forgot to add something important after what feels like an eternety of an ascent. It's nice to play with it in a mod, but often I don't have the additional time it takes to plan, design and execute a mission in RSS and I am quite convinced it is not worth the devs time to implement something that is not going to be used by the majority of players. I am not even talking about the part balancing nightmare 3 different sizes of kerbin would bring uppon us...

Your suggestions have many valid points, especially implementing something like FAR. But realistic kerbin should remain in the mod section.

Oh and since it can't be sayd enogh, thx to all those awesome moders that make ksp the game it is

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It's worth noting that a 6.4x Kerbin launch with FAR will probably take about the same amount of time as a current soupodynamics launch. People really underestimate how *long* it takes to go up 10 kilometers at 1-200m/s.

Also, how is 6371km smaller than 6000km? ;)

Yeah, I'm pretty sure I screwed up my math somewhere. My excuse: a tiring day at school, finding out an old teacher of mine has died from cancer.

EDIT: And if someone could fix my math and let me paste that into the OP, that'd be great. Right now I'm too tired.

Edited by GregroxMun
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Pretty sure the devs have said ISP will not change with tank density--the current system is an approximation but it works well enough. I don't know about rescaling Kerbin though, as others have said the increased launch times would be a pain. I already use MechJeb for easy launches, while harder launches (code for I don't want to rendezvous several separate launches to build a ship in orbit) already take a long time if you use the old trick involving spikes and a bajillion intakes, which I'm not sure OP's suggestions fix either.

Isp shouldn't change with tank density. that's not what I wrote. Isp DEFINITELY needs to change thrust instead of Fuel Flow. Right now, illogically, the atmosphere affects how much fuel is flowing from the tanks into the rocket engine, instead of the thrust. This makes NO sense.

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The correct relation between thrust & ISP is the only thing I agree on.

There's other way to get rid of the soupy atmosphere and KERBAL-SIZED planets serve a very important function : Being able to actually play the game.

Having a bigger playground doesn't matter if 99% of it is lengthy and boring to explore.

Bigger planet lead to bigger solar system which lead to greater precision requirement, leading to more frustration, frustration lead to hate and hate lead to the dark side of the Force.

Thus we mustn't for the sake of a Galaxy far far away resize KSP for any other reason than fun and gameplay.

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Rockets are already inefficient compared to real ones. Don't think of Isp in isolation; the problem is that tanks are about 4x as heavy as they should be, and engines about 3-4x as heavy. Due to how the rocket equation works, that's worth a few dozen % of your Isp (simplifying; MR is under a logarithm).

So sure, you may be getting 390s out of that LV-909 instead of the 340 you should be (~tops~), or 350 instead of 290 from a lifter (assuming KSP engines run off standard hypergolic storables, which would explain the infinite restart capability), but since your mass ratio is a quarter what it could be absent payload, you're actually less efficient.

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Rockets are already inefficient compared to real ones. Don't think of Isp in isolation; the problem is that tanks are about 4x as heavy as they should be, and engines about 3-4x as heavy. Due to how the rocket equation works, that's worth a few dozen % of your Isp (simplifying; MR is under a logarithm).

So sure, you may be getting 390s out of that LV-909 instead of the 340 you should be (~tops~), or 350 instead of 290 from a lifter (assuming KSP engines run off standard hypergolic storables, which would explain the infinite restart capability), but since your mass ratio is a quarter what it could be absent payload, you're actually less efficient.

I'm aware of that. But if the Isp were put into realistic values while leaving the fuel tanks and engines heavy, it would put dV approximately where it should be after altering aerodynamic physics to have realistic drag values.

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Before putting the Isp to realistic value (if its even needed, KSP is game first) the first step would be to respect the correct Thrust/Isp/pressure relation. The one that make Aerospike engine interesting as a SSTO engine.

However such a change would definitely ask to rework... the entire aerodynamic model, oh wait, it's planned.

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