Realism in KSP2?

[savagekerbal]

After watching Scott Manley’s Things KSP Doesn’t Teach you on rocket fuel injectors, the portion of Pintle Injectors sprouted a question in my head. The developers have stated KSP 2, while having future space travel concepts in mind, won’t contain “magic science” such as warp drives and teleportation as means of travel (hopefully still in the debug console for fun). If they’re deciding they want to swing further into the mechanics of rocket propulsion (which it seems like with the metallic hydrogen engine) do you think they’re going to categorize engines in not just propellant and thrust capabilities but also throttle capabilities? For an example, Space X’s Raptor engine, while being the champion so far for correlation of efficiency and power,  you would not want to land with a Raptor engine. The Raptor uses coaxial swirl injectors vs Space X’s Merlin Engine used on the Falcon 9s which have pintle injectors which are capable of throttling down to 10%. 
 

I don’t see them doing it because the effort probably would not be worth the outcome, however I believe it would be a cool mod to develop to make you plan your engine selection on staging. While it is still a game, it always make me laugh that you can change the thrust limiter in flight on an engine such as the Mainsail and get extremely precise burns with it.

[MechBFP]

The KSP mod Realism Overhaul adds things like unthrottable engines, limited ignitions, requirement for ullage engines, etc. While that is cool, I think it definitely either belongs in a mod or a “realistic” difficulty mode as it adds a lot of complexity that would completely turn off new players. 

Edited March 10, 2020 by MechBFP

[Guest]

You'd be surprised. Of those, only ullage engines come up with any sort of regularity. Limited ignitions are very easy to design around, if done well, though single ignition engines can be trouble on stock scale Kerbin. 

TBH, as far as realism is concerned, I'm more worried of "magic science" introduced by accident, because the devs don't know better. That's what the metallic hydrogen engine is, in fact, courtesy of recent research (see discussing in S&S subforum). 

[KerikBalm]

I wouldn't count on it, and FYI, metallic hydrogen engines are not an example of the developer sticking hard to realism.

From the videos I see, chemical engine fuel injectors will likely be ignored, because they want to go way beyond such engines, into medium-ish hardness sci-fi, and in that case, throttling for most of the engines will probably not be based on some idea of throttling limits of an engine design, since no such (complete) design exists.

I expect the nuclear pulse propulsion will have a minimum charge impulse, with throttling determining how fast it pulses though

[Guest]

Realism needs to take a back seat to fun. Realism for its own sake can quickly lead to limited, tedious, and repetitive gameplay that only appeals to a very specific niche. I would not like to have the current selection of KSP engines, except with realistically limited injection and no or limited throttling: that would drastically reduce the options available when designing somewhat off-the-wall craft. Our craft would have to look a lot more alike to be viable at all.

I do think there is one way in which limited-ignition, limited or no throttle engines could work, however: if you broke up the engines into components -- injector, combustion chamber, gimbal, nozzle, etc. -- which came in multiple variants, each with their own trade-offs, that you could then combine to create your own engines for the specific mission you had in mind. So for example if I want to design a Vector-like high-power repeated-ignition throttled engine for use in a rocket plane, I could do that, with trade-offs dictated by the engine parts I used to build it. It'd probably be heavier and certainly more expensive than a single-ignition shallow-throttle one. This would mesh well with different fuel, oxidiser, and propellant types as well.

Naturally this wouldn't preclude having a range of pre-built engines similar to the current selection for those who prefer to just stick one on and go; designing your own for specific missions would just allow you to optimise performance for that job. Like, I could get a higher TWR for less if I left out the gimbal and made it single-injection and not throttlable, or I could pick a nozzle that's optimal in the lower atmosphere of Eve, or any of a number of other things.

I think I would rather enjoy messing about with engines that way, actually.

(Ullage though? No thanks, I can't see any way that wouldn't just be pointless busywork. )

[Guest]

Just giving us a decent range of engines would work. Baseline KSP engines are a lot like hypergolics (nevermind the dev comments about LF being methane), which would have unlimited ignitions, anyway. Methane engines could have better stats, but pay for it by limited ignitions. Hydrogen engines would also pay by using a bulky fuel, on top of ignition limits.  Lack of throttle on larger engines would actually be very nice to have, because it'd discourage silly situations in which a single engine is used for lifting, OMS and docking. People should have a reason not to slap a Vector on everything just because it has the best Isp. No, realism doesn't need to take a backseat to fun. They can sit beside each other just fine. Those people who say otherwise have never played with well-designed (that is, not RO) realism mods.

Engine design, while a fun idea, would require adding a whole new dimension to the game, and while I wouldn't be against it (Space X didn't get to space on someone else's engines, after all), it's probably too big of a thing to add to KSP2 at this point.

[I likeOxidizerrfuel]

Limited ignitions and complex things like those, would add more annoyances to the game. 

[Guest]

7 hours ago, Dragon01 said:

No, realism doesn't need to take a backseat to fun. They can sit beside each other just fine. Those people who say otherwise have never played with well-designed (that is, not RO) realism mods.

I used to be into realistic flight sims, a long time ago. There is a particular appeal to them. I recently checked out X-Plane, and realized I just can’t do that kind of thing anymore, it’s dull and feels too much like work. I don’t have the patience.

Realism and fun are two different objectives, and as such it is inevitable that they will not always be aligned. As with any two objectives, you will need to know which one is primary and which one takes back seat. 

I design a lot of planes of all sizes for all kinds of different bodies in KSP. That’s fun for me. Most of these craft would simply not be possible if KSP’s engines behaved realistically. While fun could certainly be had working around the limitations, I do not believe that would outweigh the loss. 

Fact is, I just don’t care about realism in KSP much. I just like to play with space legos and get little green guys into absurd situations, so I do care about fun.

Which realism mods would you suggest?

(Engine legos would be a really simple feature to implement, certainly compared to most of the stuff under consideration. The most time would likely go into modeling the visible parts involved. Other than that it’s just a bunch of numbers and a drag-and-drop/click-to-pick UI. It would likely end up cheaper than designing a sufficient variety of prebuilt engines with different combinations of characteristics and fuel types you want so much.)

Edited March 11, 2020 by Guest

[Hotel26]

1 hour ago, Brikoleur said:

I just don’t care about realism in KSP much

One of my favorite movies is called Pushing Tin and it's a love triangle set involving two guys in ATC; two guys with completely different personalities.  Who knock heads and eventually come to terms with each other.

One of the subtexts of the movie is an acknowledgement of the real-life fact that Air Traffic Controllers mostly fall into one of two camps:

1. the guys who also fly General Aviation for recreation, and
2. those guys who love video games

Both kinds of controllers are good at their jobs, but their approaches are from totally different quarters.  And I think this is analogous to two of the major ways to approach KSP.

I don't wish nor intend to disparage anyone, but I would further characterize those camps with the attributes Knowledge vs Creativity.

This is just a metaphor but I think it helps explain the push & pull in this argument and why it's been so difficult to find a happy medium -- or at least, to terminate it.

                                                                                  

There was a discussion in this forum recently in which a topic discussed how to launch from KSC and pull up at apogee, circularized, within just a couple of kilometers from a target that moments before had had a closing velocity of over 1 km/sec.

When one can do this successfully, thinking OVERSHOOT!  OVERSHOOT! right down to the last couple of seconds, it is the most exhiliarating feeling I've ever experienced in KSP!  Someone chimed in and said they didn't do it that way because the NASA way is to spend one full orbit sidling up to the target and closing in for the final rendez-vous at a very slow speed.

I suppose there can be tremendous satisfaction in knowing that you've done it the way it's meant to be done in real life?  I will never find out.

Edited March 11, 2020 by Hotel26

[dave1904]

There are mods that force you to stay on 100% throttle all the time. Realism Overhaul gets as real as it gets for the most part. If I am not mistaken the SSME was also in theory capable of going all the way down to 30% or something like that but there were some issues. I am to lazy to look it up but dont quote me on that. For gameplay sake I do not KSP2 should be that complicated. Mods can do that. 

 

[Vanamonde]

Don't let the metallic hydrogen argument hijack yet another thread, people. Those comments have been removed since the argument already exists in other threads and is just repetition, and it's a repetition which was already getting into insults. 

[Rejected Spawn]

Regarding throttling I like to think of it as a gamey way to compensate for us not having any ship computer assistance in firing the engines; real life rockets can be wired to count the milliseconds of a burn and automatically turn on/off but we have no choice but to whack away at a keyboard all "oldschool" like, fully manual burns at all times. Any burn is simply meant to make a speed alteration, 100 milliseconds at full throttle or 2 seconds at an impossible 5% throttle end up with essentially the same result. Sure it's crazy how many times the rockets we build can reignite by that logic but it feels far less far fetched than throttling being actual throttling; we're simply given an unrealistic limitation and an unrealistic tool to overcome that limitation and make the end result a little more realistic, I'd say that's fair enough. Also apparently two wrongs can make an almost right, how about that. Not expecting any significant changes to throttling in KSP2 (for those "old" chemical rockets, you don't throttle an Orion) and frankly I don't think there needs to be any change either, I'm with the other voices here that speak in favor of games being allowed some creative freedom. Would appreciate automation in burns (and beyond) but that's another topic entirely.

[Guest]

7 hours ago, Rejected Spawn said:

you don't throttle an Orion

I thought throttling an Orion would be pretty easy, just drop fewer bombs or dial down the yield.

[Superfluous J]

43 minutes ago, Brikoleur said:

I thought throttling an Orion would be pretty easy, just drop fewer bombs or dial down the yield.

If you're just trying to not speed up so quickly then sure, but if you are trying to match a maneuver node each bomb will still give you X more speed no matter how often you drop them. If you need 50m/s and they give you 1500...

And how do you dial down the yield? The only way I can think of is to bring an array of bomb sizes.

Edited March 12, 2020 by 5thHorseman

[Guest]

3 minutes ago, 5thHorseman said:

And how do you dial down the yield? The only way I can think of is to bring an array of bomb sizes.

https://en.wikipedia.org/wiki/Variable_yield

[brain__washed]

18 minutes ago, 5thHorseman said:

And how do you dial down the yield? The only way I can think of is to bring an array of bomb sizes.

What about tinkering with the timer? Nuke explodes further away, you get less momentum

[Superfluous J]

1 hour ago, Brikoleur said:

https://en.wikipedia.org/wiki/Variable_yield

1 hour ago, brain__washed said:

What about tinkering with the timer? Nuke explodes further away, you get less momentum

These both sound terrible from an efficiency standpoint. Imagine if any other engine in the game used the same amount of fuel no matter how low you throttled down.

[Guest]

56 minutes ago, 5thHorseman said:

These both sound terrible from an efficiency standpoint. Imagine if any other engine in the game used the same amount of fuel no matter how low you throttled down.

They are, but presumably you would only need them in exceptional circumstances. (Can't think when, TBH.)

[brain__washed]

1 hour ago, 5thHorseman said:

These both sound terrible from an efficiency standpoint. Imagine if any other engine in the game used the same amount of fuel no matter how low you throttled down.

I hadn't thought of that tbh, I guess you would use conventional thrusters for finetuning instead then. Would also not exactly make sense to blow nukes to circularize an orbit, more to brute force a brachistrochrone trajectory.

[savagekerbal]

On 3/11/2020 at 8:50 PM, Rejected Spawn said:

Regarding throttling I like to think of it as a gamey way to compensate for us not having any ship computer assistance in firing the engines; real life rockets can be wired to count the milliseconds of a burn and automatically turn on/off but we have no choice but to whack away at a keyboard all "oldschool" like, fully manual burns at all times. Any burn is simply meant to make a speed alteration, 100 milliseconds at full throttle or 2 seconds at an impossible 5% throttle end up with essentially the same result. Sure it's crazy how many times the rockets we build can reignite by that logic but it feels far less far fetched than throttling being actual throttling; we're simply given an unrealistic limitation and an unrealistic tool to overcome that limitation and make the end result a little more realistic, I'd say that's fair enough. Also apparently two wrongs can make an almost right, how about that. Not expecting any significant changes to throttling in KSP2 (for those "old" chemical rockets, you don't throttle an Orion) and frankly I don't think there needs to be any change either, I'm with the other voices here that speak in favor of games being allowed some creative freedom. Would appreciate automation in burns (and beyond) but that's another topic entirely.

True but I’ll sell one of my kidneys if MechJeb (or a similar system) wouldn’t be made available. I mean KSP is limited to interplanetary travel and even a trip to Laythe requires a precise burn for efficiency. However with interstellar travel that precise burn needs to be extremely more precise. I don’t see why people see an automated burn as cheating. I mean maybe a calculated advanced planet to planet transfer but Simple Rockets 2 has the automated burn and I see even Scott Manly doing it and no one bats an eye.

[OOM]

If the new "Interstellar" mod will be released for KSP 2. Then there is no doubt in realism and in-depth calculations.

The stock version is likely to be an arcade.

On 3/14/2020 at 1:57 PM, savagekerbal said:

True but I’ll sell one of my kidneys if MechJeb (or a similar system) wouldn’t be made available. I mean KSP is limited to interplanetary travel and even a trip to Laythe requires a precise burn for efficiency. However with interstellar travel that precise burn needs to be extremely more precise. I don’t see why people see an automated burn as cheating. I mean maybe a calculated advanced planet to planet transfer but Simple Rockets 2 has the automated burn and I see even Scott Manly doing it and no one bats an eye.

KSP is not limited to interplanetary travel. Install the GU and remove this restriction.

Spoiler

 

ps.

Spoiler

And I would not recommend using MechJeb

 

Edited March 25, 2020 by OOM

[Bej Kerman]

On 3/10/2020 at 7:52 PM, Dragon01 said:

Limited ignitions are very easy to design around

That's easy to say if you've been playing for 500 hours and have no clue what newer players experience.

[shdwlrd]

21 minutes ago, OOM said:

And I would not recommend using MechJeb

Why not? 

[OOM]

4 minutes ago, shdwlrd said:

Why not? 

Because it is bad. A primitive machine will never replace human logic and reason. In addition, this takes away an important part of the game - piloting your own spaceship.

Edited March 25, 2020 by OOM

[Bej Kerman]

34 minutes ago, OOM said:

KSP is not limited to interplanetary travel. Install the GU and remove this restriction.

  Hide contents

GU isn't restricted to interplanetary travel, but KSP is.

5 minutes ago, OOM said:

Because it is bad. A primitive machine will never replace human logic and reason.

But it will always replace human reaction times and human irrationality.

5 minutes ago, OOM said:

In addition, this takes away an important part of the game - piloting your own spaceship.

Yeah, but what about going back and forth between Space Station V and Munbase Alpha for an indefinite time to supply parts and resources? That's extremely tedious and you don't learn much.