The real size of the KSP planets compared to Earth

[Dakitess]

15 hours ago, The Aziz said:

Read as: impossible.

Definitely doable, already did it just like a bunch of other players in RSS.

Clearly not ideal and it will put a hard limit on tiny payload and efficient crafts, but this is nothing like impossible.

You know, EVE was about 10km/s of DeltaV, with a crushing atmosphere, and you had to get there, land, before being able to take off, which mean a WHOLE lot more difficulty as you had to launch from Kerbin a... rocket embedding a payload able to do this 10km/s. With Stock Parts. And thick atmo that would destroy your ISP.

So yeah, far from impossible. And quite interesting to me to actually get this end-game need to streamline the craft, to think them differently because of the new constraints : yeah, if Kerbin had been 10 times bigger, you would have never been able to get to another star system, or simply to colonize the whole kerbal system "so easily".

And, as said, there is no problem to then get some end-game scalable parts, adapted to the new Real Scale environment.

[Periple]

On 9/13/2023 at 5:50 PM, Dakitess said:

I really really really would like to see the Real Solar System as an end-game interstellar destination. With the same parts and all, to represent a whole new challenge for KerbalKind, and maybe some additionnal bigger ones as an extension or (obviously) mods.

I don't think it would work for the stock game. For one thing the planetary physics would just feel wrong — you'd have a Jool-sized rocky planet with Kerbin gravity and very similar atmosphere. Also it would throw the parts balance way out of whack, and if it was an end-game challenge, it really wouldn't be much of a challenge with nuclear salt water rockets, metallic hydrogen engines, and whatever else they've come up with for the interstellar stuff.

A RSS/RO mod for KSP2 would be amazing of course!

[Dakitess]

Ha, I must say that I've 'ever thought about the Gravity homogeneity ! Indeed, it would make no sense to get same SeaLevel Gs on a real scale earth than on our tiny Kerbin.

 

[Infinite Aerospace]

On 9/13/2023 at 7:18 PM, Alexoff said:

The small size of planets is compensated by the low efficiency of kerbal's rockets. Empty tanks are too heavy; with such rockets we would not even reach orbit.

Yup, take the Vector as a prime example being the in-game analogue of the RS-25 engine, looks 'similar' but more than 100 seconds of ISP short and about a third of the overall thrust whilst somehow being heavier than the real world version. I personally think 2.5 - 3.5 scale (vs. Stock KSP) is the sweet spot and I would love to see that as an actual option rather than having to have that modded in.

[KerikBalm]

On 9/13/2023 at 1:27 AM, HephaistosFnord said:

I'm hoping KSP2 eventually gives us a 6.4x scaleup option in the 'difficulty' settings

I prefer 6.25x, ie 2.5^2.

It's easier to multiply orbital periods and dV requirements by 2.5x than... checks sqrt 6.4= 2.529822

I would have there be various difficulties

Difficulty: rescale factor: orbital period and approximate dV multiplier

Easy: 1x: 1x

Medium: 2.25x: 1.5x

Hard: 4x: 2x

Expert: 6.25x: 2.5x

Or maybe, depending on bodies and part stats:

Easy: 1x: 1x

Medium: 4x: 2x

Hard: 9x: 3x

Hard would be close to "real" scale, and would require parts with stats quite a bit better than those found in KSO1.

In all cases, I wouldn't scale the atmosphere up by more than 1.25x

On 9/13/2023 at 8:18 PM, Alexoff said:

The small size of planets is compensated by the low efficiency of kerbal's rockets. Empty tanks are too heavy; with such rockets we would not even reach orbit.

Not true, you can make orbit in RSS with stock parts, payload fraction is terrible though.

1x scale is still much easier than real life - compensation is partial at best.

I find 3-4x rescales to be about right for balance purposes. 6.25x gets to the limit.

With a 350 isp LFO engine (poodle), you're getting a proportional dV less than that of a hyrdolox engine, while being saddled with poor mass ratios due to heavy empty tanks, and poor rocket TWR.

For saves where I enable KRnD in KSP1, I play at 6.25x

[Alexoff]

19 hours ago, KerikBalm said:

Not true, you can make orbit in RSS with stock parts, payload fraction is terrible though.

I'm aware, I've flown with stock parts to Mercury and back. But in real life, such inefficient rockets delayed the space age by a hundred years.

[Brofessional]

On 9/13/2023 at 12:41 AM, The Aziz said:

Oh how typical. 90% of the players struggles to land on the Mun even when it's this tiny

That 2% of mad people: MAKE IT EVEN HARDER

Changing the planet/moon scale doesn't really affect the difficulty because the mini scale versions have the same gravity. They are scaled down in the first place primarily because it's easier for the engine to deal with and less work for the artists.

[Periple]

2 hours ago, Brofessional said:

Changing the planet/moon scale doesn't really affect the difficulty because the mini scale versions have the same gravity. They are scaled down in the first place primarily because it's easier for the engine to deal with and less work for the artists.

I think they’re scaled down for gameplay reasons! If it took 10 minutes just to get to orbit every time that would get boring!

[kdaviper]

57 minutes ago, Periple said:

I think they’re scaled down for gameplay reasons! If it took 10 minutes just to get to orbit every time that would get boring!

Also at less Delta v required to get into orbit!

[Gotmachine]

On 9/13/2023 at 7:41 AM, The Aziz said:

Oh how typical. 90% of the players struggles to land on the Mun even when it's this tiny

That 2% of mad people: MAKE IT EVEN HARDER

People can't land on the Mun because they fail to either understand or put into practice concepts like staging, deltav, twr, gravity losses, orbital flight planning, node execution, suicide burns, attitude control...

In many cases, the game is failing at teaching those concepts, or could have better tools to interact with them.

But the scale of the bodies is a very minor factor, as long as the parts isp and density is decently balanced. Like many veteran KSP players having played with various non stock scales, I agree that the stock system scale gives a toy system feeling, which imo is detrimental as it destroy the sense of achievement. Space doesn't feel big, the rockets don't feel big.

[MarcAbaddon]

49 minutes ago, Gotmachine said:

Like many veteran KSP players having played with various non stock scales, I agree that the stock system scale gives a toy system feeling, which imo is detrimental as it destroy the sense of achievement. Space doesn't feel big, the rockets don't feel big.

Strong disagree with this - the reduced scale was one of the best and most important design choices of KSP 1. As Periple mentions, few players want to spend 10 minutes every single time just to fly a rocket into orbit. Or to take a few hours to get to certain parts of the planets even when flying at Mach 3. 

Sure, I have played with the real solar system mod too, and it is a nice additional way to play the game. But the reduced scale is a much better fit for the main game.

Also - I don't really get the feelings things are super small. Maybe because Kerbals small too and I tend to compare to them?

[Gotmachine]

7 hours ago, MarcAbaddon said:

the reduced scale was one of the best and most important design choices of KSP 1

I agree real scale has some disadvantages. But 1/10th scale is really tiny, as highlighted by OP, and you can actually feel that in many ways.
A lot of people have a very positive feedback with the 1/4 or 1/3 scales.
I can't help to think that "we want to make you feel that space is big" decision that led to the interstellar scope in KSP 2 could (and maybe should) have been avoided by revisiting the stock scale (and system) instead.

Edited September 19, 2023 by Gotmachine

[cocoscacao]

8 minutes ago, Gotmachine said:

But 1/10th scale is really tiny, as highlighted by OP, and you can actually feel that in many ways.

Eh, in what ways? I don't see more empty terrain as an improvement. 

[Gotmachine]

25 minutes ago, cocoscacao said:

Eh, in what ways? I don't see more empty terrain as an improvement. 

Terrain is just as empty anyway, this has nothing to do with scale, but everything to do with the lack of a proper high detail procedural terrain solution.

Edit : there are many ways a larger scale improves immersion. In the end, it comes down to adequately scaling a given technology with what is supposed to achieve in the real world. It means larger rockets and contraptions in general, more incentive to do complex missions with stuff like orbital assembly and resupplying, more incentive to actually have off-world bases and stations. Once you have understood the basics of rocket building and orbital/interplanetary navigation, it's way too easy to go anywhere and do everything in KSP. To me, expanding the scale of the Kerbal system to something like 1/4 and revamping it with new places would have been much more in the spirit of KSP than expanding the scope to science fiction interstellar technologies. There are 80 planets, moons and other bodies with larger than the KSP Mun radius in the solar system, countless asteroids and comets, with tons of unique features, including ones that could have actually meant something in terms of gameplay. I know it isn't a popular opinion, but while KSP 1 was briliant at defining a new sub-genre, a lot of the justifications for many of its technical and design decisions didn't have much validity anymore 10 years latter and should have been questioned when making a sequel, instead of taking everything KSP 1 did and just envisioning that sequel as a big DLC.

Edited September 19, 2023 by Gotmachine

[Lyneira]

An important consideration when scaling up the solar system will be SSTOs. Both rocket and airbreathing spaceplane SSTOs will be affected.

Rocket SSTOs might become entirely infeasible, which would be consistent with the situation on earth and make it more important for the game to facilitate returning first stages to a landing pad.

Airbreathing spaceplane SSTOs in the 1/10th scale system achieve a high fraction of their orbital speed in atmosphere on efficient airbreathing engines (around 1500 m/s compared to the ~2200 m/s orbital velocity in LKO), which explains why they achieve such good payload fractions. This will change in a larger scale solar system because a spaceplane SSTO will need to do much more of the work on rocket power.

If the solar system were scaled up, I think I'd prefer to see chemical rocket SSTOs consigned to KSP history while preserving airbreathing spaceplane SSTOs as feasible.

[Dakitess]

I would not mind at all having difficulties to built SSTO or to make them more benefitable than classical rockets.

Since it's KSP, with all its approximations and forgiveness, there is no doubt we would still be able to build SSTOs in Real Scale with Kerbal-rated parts. We would just had to stick to high efficiency design, waaaaay smaller Payload mass ratio, rather that the actual 50% which is... well, it's fun and all, but its way way way way way too much to let the basic rocket has their own interest.

With the real bonus of getting back the entire vessel in IRL and KSP, and without the real malus of being sure it returns well, don't diminush too hard the reliability, and is not hell of expensive to maintain in operational condition that we would not have in KSP (or would we ? It would still be very interesting !), there is no doubt about their interest, with an additionnal challenge. And in addition, it would totally make Two-Stages craft a real thing to explore, as it would be the perfect sweet spot that we don't explore today, except when we Role-Play.

I know, I know, this kind of considerations were held as "gate-keeping" when we first discussed about it, some months ago, especially on Discord. This is nothing like elitism, like, really, just some insight about challenge, difficuly spread along start-mid-end game etc.

Edit : there is so many typo and grammatical error that I won't correct them, sorry, had a very tough night

Edited September 20, 2023 by Dakitess

[shdwlrd]

If you're spending most of you play through in space, I can see the allure of increasing the size of the solar system. If you spend any good amount of time traveling on the celestial bodies, they seem big enough. I'd rather fly a couple hours at Mach .8 to go from the equator to the pole than what's considered a regional flight in the US.