Atmosphere changes -> rebalance time, thoughts?

[KerikBalm]

So they are going to "fix" the atmosphere model, and it sounds like it will basically be what NEAR is currently.

The immediate effect of this, is that it will be a lot easier to get to orbit, and that the difficulty of getting to orbit vs going somewhere else will be more in line with "intuition" or "reality" (ie, getting to orbit is supposed to be halfway to anywhere, not 3/4s of the way.... 4,500 m/s to get to orbit, but only 1,100 more to get to duna...)

They also mention part rebalance and specifically a look at the 48-7s... (considering Tavert's charts, this is quite justified)

But with the atmosphere changes... I think we could see a huge rebalance...

They could do nerfs across the board so that you need an equally big rocket to get to orbit... (and going other places is much harder) or they could just leave the first milestone as easier to accomplish.

But there are other things that need to be looked at, what are your thoughts on them/ suggest more:

#1) Air breathing engines, fuel consumption and maximum velocity... the latter should be nerfed as in NEAR/FAR, the former we're already somewhat prepared for because if the better liquid fuel tanks we have available

#2) Engine thrust - with a new aero model, we're encouraged to build tall, skinny rockets. That means we may need more thrust under a single stack. Perhaps some engine thrust should be buffed (mass can increase to keep TWR the same)

#3) Specific engine balance:

* there's already a thread for that

#4) Engine balance in general

We need more engines with ISP ranges like the LVN, the poodle, the KR-2L, and the 25x4: 220-800, 270-390, 280-380, 320-360

-What we see here is that the better the vacuum ISP, the worse the atmospheric ISP.

In theory, the 25x4 is better suited as a lower stage, and the KR-2L as an upper stage... but the better TWR of the KR-2L sort of skews that.

IMO, there should be a pretty standard TWR for each engine diameter (perhaps skewed a little higher for engine with worse vacuum ISP), and all that varies is weight, and the ISP spread.

IMO the poodle-skipper-mainsail line is a pretty good model (but I'd nerf the atmospheric ISP of the skipper down to 310) for the rest to follow.

#5) Ion propulsion - sure we don't have thrusting during high timewarp, or a way of doing maneuver nodes for very long thrusts... so for gameplay/engine limitations, high TWR is needed.

IMO, back when they quadrupled the Ion engine thrust, they should have nerfed its ISP by half.

Also.... Xenon gas is about 400x the cost per kg of standard rocket fuel... I think this is too much

Thoughts?

[WWEdeadman]

Yeah, with the new atmosphere there should be an all over re-balancing. And AFAIK they're doing that. I, of course, have no idea what changes exactly they are doing, but an all over re-balance is in the works, for all I know.

And specifically to the Ion-engine: Yes. The Ion Engine, even with the incredibly over the top exaggerated power (compared to the reallife one) it currently has, is absolutely useless, from a money efficiency and a time standpoint. No one will spend 3 hours "burning" that damn engine, and I surely won't waste tons of funds on Xenon gas, if I could use a nuclear engine instead and have that be cheaper. (Although, even the LV-N can make for a pretty useless engine, if you have heavy payloads. Almost the same burn times as the freaking ion engine, sometimes)

[Toastedbuns]

Yeah, with the new atmosphere there should be an all over re-balancing. And AFAIK they're doing that. I, of course, have no idea what changes exactly they are doing, but an all over re-balance is in the works, for all I know.

And specifically to the Ion-engine: Yes. The Ion Engine, even with the incredibly over the top exaggerated power (compared to the reallife one) it currently has, is absolutely useless, from a money efficiency and a time standpoint. No one will spend 3 hours "burning" that damn engine, and I surely won't waste tons of funds on Xenon gas, if I could use a nuclear engine instead and have that be cheaper. (Although, even the LV-N can make for a pretty useless engine, if you have heavy payloads. Almost the same burn times as the freaking ion engine, sometimes)

"I'd love to spend my afternoon getting to the Joolian system for 50 science." - literally no one

I'd like if you could set things to autoburn in the background, would that make ion more of useful investment? Yes.

Two problems with ion is time and money, the devs only put in there as a metaphor for real life

[Jouni]

#2) Engine thrust - with a new aero model, we're encouraged to build tall, skinny rockets. That means we may need more thrust under a single stack. Perhaps some engine thrust should be buffed (mass can increase to keep TWR the same)

This is a problem with the current 3.75 m engines. The smaller engines are ok.

The Mainsail and the KS-25x4 have roughly the same thrust per unit area. Their thrust is about the same as the weight of a 30 m stack of fuel tanks. A 2.5 m rocket powered by a Mainsail can be almost too tall and too thin, while a 3.75 m rocket powered by a KS-25x4 looks too short. This could be fixed by making the engine cluster comparable to the LFB: 4500 kN of thrust with a low Isp. (On the other hand, the KS-25x4 is supposed to be a low-thrust high-efficiency engine cluster that can't even lift the SLS first stage on its own. Maybe we need a new 3.75 m engine instead.)

[Rosco P. Coltrane]

Am I the only one concerned about the nerf on the 48-7S?

If they cut down the thrust then I'm ok with it, the thing has too much thrust for its size/weight. But if they also reduce the Isp, then we might be out of options when it comes to small probes and satellites.

[regex]

Is any of this "easier to get to orbit" hype even confirmed or is this just wild speculation?

[katateochi]

I have a bunch of conflicting feelings about this; while I do want better aerodynamics I don't like the idea of it being easier to reach orbit. While an engine nerfing would re-balance that, I'm worried that it would be a move towards real at the expense of fun.

My main concern is about nerfing the Jet engine. One of the things I really enjoy is flying as fast and as low as possible and my fear is that if the Jet gets nerfed then this sort of flying will stop being fun. If it's just its high alt performance that is nerfed or if the change to drag compensates then I'll be ok with it.

Some might argue that the speeds that are currently possible are unrealistically fast, but there is a counter to that. Our perception of speed is based on optic flow (the rate of stuff rushing past your eyes) and the problem with KSP is the terrain is so sparse that it doesn't provide much stimulus for optic flow, so you have to go even faster to feel the speed. This is why many of us want unnatural speeds out of our rovers and why "pottering" around at 50m/s (~110mph) feels slow. If the terrain was more detailed, the speed fiends would be content with lower velocities, alternatively; in this unnaturally sparse terrain I feel unnaturally powerful engines are acceptable.

I also feel the Jet engines are a rather special case. They're the only form of propulsion in KSP that is restricted to just two bodies, so their scope of use is very much more limited than the other engines (so be nice to them ). Aside from SSTO applications their other purpose is to open up exploration of Kerbin, so that needs to remain efficient, fun and something that is enticing (ie doesn't make you feel like your playing a long-haul flight sim) because Kerbin is really worth exploring, its quite possibly the most interesting planet! (which is perhaps something else that needs addressing)

[KerikBalm]

Well, its an inference. If one part can shield another from drag, then it should follow that you'll have less drag.

They could increase the base part drag to compensate... but...

There is also the case that currently full fuel tanks produce more drag than empty ones (so terminal velocity is always the same for a fuel tank regardless of its fuel state).

Since that is also going away, the inference is again that terminal velocity on your rocket will be going up, and you can ascend at much higher speeds and lose less to atmo+ gravity drag.

With what they've said they'll do, it seems very very very likely that it will take less dV to get to orbit. Perhaps even 1k m/s less... ie more on the order of 3,500 instead of 4,500.

There's already mods that do what they say they're going to do that give us a clue.

Stock drag fix would be one (it makes the drag of fuel tanks independent of fuel level) bound

The other would be NEAR.

I have a bunch of conflicting feelings about this; while I do want better aerodynamics I don't like the idea of it being easier to reach orbit. While an engine nerfing would re-balance that, I'm worried that it would be a move towards real at the expense of fun.

My main concern is about nerfing the Jet engine. One of the things I really enjoy is flying as fast and as low as possible and my fear is that if the Jet gets nerfed then this sort of flying will stop being fun. If it's just its high alt performance that is nerfed or if the change to drag compensates then I'll be ok with it.

Have you tried NEAR?

The reduced drag lets you get going much faster in the atmosphere, and the v^2 dependancy of lift really lets you put on the Gs when turning.

NEAR/FAR nerfed the top speeds of jets and turbojets, perhaps basic jets were nerfed too much... but you should still be able to zip around at 300 m/s at low altitude even with basic jets (and I don't imagine that basic jets will get such a nerf, turbos and rapiers reall need their max speed nerfed down to about 1,600 m/s or so)

Edited February 2, 2015 by KerikBalm

[cantab]

I'd like if you could set things to autoburn in the background, would that make ion more of useful investment? Yes.

Well, you kind of can, with the new superSAS. When it works you just set to follow a direction and let it go. Keep half an eye on the situation while you do something else. Only snag is the superSAS struggles with ships that either have too much or too little control authority. Also factor in that ions shine for small probes which also take 4x physics warp well, and they're actually decent as they are. The main problem IMHO is lack of big xenon tanks, they'd be more feasible for small-medium kerballed missions if we had bigger xenon tanks.

[NERVAfan]

Ions are just niche anyway -- KSP-system delta-V requirements are very low and nuclear engines are available.