Problems with aero

[joshtemplin3]

So, like what you'd expect from someone like me posting a thread here, right now;

1) I'm a relatively long-time player (that has never used FAR!) that's having to switch to 1.0[.x] physics and I'm having a lot of trouble. I've tried sleeker rockets, payload fairings, fins, starting from 1km and slowly turning (instead of the 10km-45° trick), etc. Even the most basic of rockets, I can barely get into an orbit.

2) Also, I've looked around the forum a lot, and to me, it seems like a lot of you just want a real life simulator rather than the quirky, semi-unrealistic game that KSP is. In the area of realism, FAR mechanics sound cool, but I would rather it be in a mod than part of the core functionality of KSP.

Part of what made KSP fun for me was that it was relatively easy to design a ship and get into orbit (hard in other scenarios, though; SSTOs), but you have to know what to do (or how to do it) from then on. In the small picture, making the process of getting into orbit harder means that, in this case, you have to completely relearn everything, and if you even manage to get into orbit, you have so little fuel left that you can't do anything such as a transfer to the Mun.

Another thing I heard/somewhat experienced is that engine thrust was messed around with, and that in space, it's less than compared to before. I completely disagree with this, no matter how realistic this new system is. The old one was good for everyone as I recall, no?

1) Tips for the current aero?

2) Opinions?

Edited May 16, 2015 by joshtemplin3
Fixed title

[SpacedCowboy]

Third thread in almost three years?! And you've been around this long, asking such questions? Sorry, don't get it.

[Snark]

Certainly it takes some re-learning, but I've found it not too hard to make the adjustment and can launch orbital, Mun missions, Minmus, etc. Am just now working up to interplanetary, but my first Duna probe is already on its way.

Do you have any specifics of exactly what sort of problem you're having with "can barely get into orbit"? Is it because your rocket is flipping? Or you just run out of fuel, or what?

I find that the rocket experience isn't too different from what it was before, but there are really just three big things to watch out for:

1. Rocket design & ascent profile need to be done "right" to avoid flipping.

2. Rockets need to be aerodynamic or they waste their fuel on drag.

3. There are several engines that have been tweaked to be "orbital" engines-- they used to be OK for launching, but now aren't anymore. Their surface Isp has gone to hell and you really don't want to use them in lower atmosphere. This includes the "Terrier" and the "Rhino".

So I guess the first question is: is your problem with rockets flipping, or something else? And if it's not flipping, is it insufficient delta vee?

[joshtemplin3]

Third thread in almost three years?! And you've been around this long, asking such questions? Sorry, don't get it.

Speaking of threads, I just noticed I forgot to change my title from when I was looking at the preview (I was going to change it later). Whoops, lol... Edit: Fixed

and, I've played KSP for a while now but only really started visiting the forums recently, so there's that.

Certainly it takes some re-learning, but I've found it not too hard to make the adjustment and can launch orbital, Mun missions, Minmus, etc. Am just now working up to interplanetary, but my first Duna probe is already on its way.

Do you have any specifics of exactly what sort of problem you're having with "can barely get into orbit"? Is it because your rocket is flipping? Or you just run out of fuel, or what?

I find that the rocket experience isn't too different from what it was before, but there are really just three big things to watch out for:

1. Rocket design & ascent profile need to be done "right" to avoid flipping.

2. Rockets need to be aerodynamic or they waste their fuel on drag.

3. There are several engines that have been tweaked to be "orbital" engines-- they used to be OK for launching, but now aren't anymore. Their surface Isp has gone to hell and you really don't want to use them in lower atmosphere. This includes the "Terrier" and the "Rhino".

So I guess the first question is: is your problem with rockets flipping, or something else? And if it's not flipping, is it insufficient delta vee?

Rockets flipping, winglits (such as the AV-R8) doing the opposite from what I want; making the craft unstable, mainly. I haven't tried to use the Rhino for liftoff yet, since I wanted to get a design that worked at all before I started going bigger. (and the Terrier just because it's a small engine, why bother? )

Edited May 16, 2015 by joshtemplin3

[Geschosskopf]

Kerbin and, by extension, its atmosphere, is made of some exotic, ultra-dense form of matter only possible under physical laws very different from our own, starting with first principles like the nuclear strong and weak forces. As a result, Kerbin and Earth have nothing in common on the periodic table, and therefore, imposing an Earth-like atmosphere on Kerbin is more wrong that any other arbitrary set of values.

[n0xiety]

I personally like new aero because planes are now actually acting realistic enough but not too realistic that it wouldn't be fun. I always liked games that are harder since harder means more challenge and more challenge leads to more gameplay time for me. If an absurd design would be able to fly as good as a logical design then where would be the fun in trying to build something better. Yes we were able to lunch whole space stations that had girders going all over the place and maybe as wide as 50 meters sitting on top of a rocket in that soup of an atmosphere but now its more of a challenge to build something like that and design it modular so that it can be launched.

[basic.syntax]

There's a lot of virtual ink already spilled on this subject, with many tips and advice. I'd take a look at

Helpful 1.0 observations

[Eric S]

On the poll, I think the poll needs different answers. There are people that don't like the current aero because it isn't realistic enough. It really is more forgiving than reality.

On the simulation-vs-game, I think it needs to be realistic enough that common sense applies, and the old aero was so far off of reality that things that there were things that would make a real rocket or aircraft perform better actually make the corresponding KSP craft worse. If it were subtle effects like ground effects, that would be one thing, but the old aero system didn't even factor the cross area of a part in determining its aerodynamic drag.

On the topic of tips to help you get to orbit, I'd suggest starting off reading this forum thread. It's not comprehensive, but it at least touches on the reasons rockets flip during launches. The post mostly goes into rocket design, not the piloting.

On the piloting, my suggestions are:

1) If you're having problems with flipping, go slow. If you're seeing mach effects, you're going fast enough to make it harder on yourself. The faster you go, the stronger the aerodynamic forces are, so if they want to flip them, going fast makes it that much harder not to flip. I tune my rockets so that they spend most of the time in the 1.3-1.7 TWR range. No, I'm not saying 1.7 TWR on lift off, because your TWR will go up as you burn off fuel.

2) Always keep your craft aimed within five degrees of your surface prograde marker if you're below 20-25km altitude. The farther off of prograde you point, the stronger the aerodynamic forces are. I've got a few craft where even going that far off of prograde results in a flip.

If you've done all this and still can't get to orbit consistently, then I'd recommend posting a screenshot of your craft along with a description of your ascent profile (how fast you're going and how far you're tipping at various altitudes in the 1-20km range).

[KSK]

OK, in reverse order.

Opinion - I like the new system. It didn't take long at all to get used to and my designs were pretty much all transferrable to the new aero. Maybe that's just because my previous designs were boring. Neither am I noticing a lot of difference in how I use the engines. The Terrier still makes a decent upper stage booster for 1.25m diameter payloads and a serviceable on-orbit engine for getting larger craft (based on 2.5m parts) to the Mun and landing on it. When I start building heavier things like chunks of space stations, I expect the Poodle will be a useful replacement. Nuclear powered craft I haven't played with yet.

Tips:

Not really a tip but hopefully some encouragement. This will get to Munar orbit and back. Beyond that - what Eric S said. Watch out for Mach effects and throttle back a bit if necessary, 25km is a more reasonable height to be pointing at 45 degrees (rather than the the old 10-15km) and if you're using SRBs, it might be worth tweaking them for reduced thrust, since they can give you too much thrust to weight for light craft.

Good luck!