[1.3.1] Ferram Aerospace Research: v0.15.9.1 "Liepmann" 4/2/18

[sashan]

Yes, it can change it according to strength slider. Useful to prevent aerodynamical failures.

As a side note: Can anyone post some rockets that work with FAR? Can't get my standard designs to work, mainly bacause the fairing takes 1/3 of the rocket length.

[Wanderfound]

As a side note: Can anyone post some rockets that work with FAR? Can't get my standard designs to work, mainly bacause the fairing takes 1/3 of the rocket length.

Gimbal is your friend:

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Craft file at https://www.dropbox.com/s/1m53ww9y81bh5qm/Krokoduck%20SP.craft?dl=0

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Basically, either have a moderate amount of gimbal and a slick payload or a draggy payload and a lot of gimbal. Strapping on some radial Verniers (e.g. Thuds) adds a lot of gimbal in a hurry.

If you're running boosters that don't gimbal, then you need active control surfaces. But if you're still running gimbal-free at altitude, those control surfaces won't work as well any more, so you'd better have an intrinsically stable craft by that point.

If you've got a slick payload, you can get away without fins (see above) or without gimbal, but probably not both unless you're very good. If you've got a draggy payload, pile on as much stability as you can; fins for the lower stages and gimbal that stays with you until space.

Fins on the boosters and verniers on the core will cover most things, though. Make your fairings as pointy as you can; drag and stability are helped by avoiding sudden changes in cross section at the top of the craft.

Edited June 1, 2015 by Wanderfound

[kcs123]

Yes, it can change it according to strength slider. Useful to prevent aerodynamical failures.

As a side note: Can anyone post some rockets that work with FAR? Can't get my standard designs to work, mainly bacause the fairing takes 1/3 of the rocket length.

I will upload some new craft designs to my craft exchange thread(link in signature) later tonight. I will put some rockets there too, made mostly for career, level one or level two of launch pad/runway and SPH/VAB.

But if you seek for more examples, better try official FAR exchange thread, link is in OP and my signature too.

[Cairol]

When installing FAR, the "More Info" menu (on mouse right click) of all control surfaces disappears. (Instead, "No more info" is shown for wing tips, winglts, tail fins, ...)

Ist this a bug?

Or is it intentionally removed because the values would not match with FARs aerodynamics model?

If the latter: How do I get an idea which winglet ect. provides what potential amount of control?

[g4368744]

My control surfaces (elevators) become unresponsive soon after passing mach 1, and again at around mach 1.4 or later. In both cases, control is restored spontaneously as I pass some critical velocity. What causes this? Seems to happen when the airflow over the elevators (and flaps) becomes supersonic, but it works afterwards. If I change the wing sweep will I be able to change this speed?

Also, for the last part of atmospheric climb out the airplane gets less stable on the roll axis, and needs constant corrections to stay level. I read that SR-71 pilots experienced the same thing. What causes this?

[Crzyrndm]

It's not a bug. FAR doesn't use it, so all remnants of the stock system need to be removed to prevent odd bugs (like the CoL arrow returning). All parameters FAR uses are based on shape, so a control surface that looks larger will give you more control (given the same position relative to CoM of course).

[blowfish]

My control surfaces (elevators) become unresponsive soon after passing mach 1, and again at around mach 1.4 or later. In both cases, control is restored spontaneously as I pass some critical velocity. What causes this? Seems to happen when the airflow over the elevators (and flaps) becomes supersonic, but it works afterwards. If I change the wing sweep will I be able to change this speed?

http://i.imgur.com/yZawuX0.jpg

Do you have DPCR enabled, and if you do, what dynamic pressure are you flying at. DPCR reduces control authority as dynamic pressure goes up so that you don't destroy your wings, but the scaling constant may need adjustment in order to still give you good authority.

[gayski]

Great work Ferram as always. I seem to be encountering a problem however where FAR just 'switches off'. I get no drag or lift or anything it seems - which means reentry or flying just doesn't happen when it occurs - I just end up going ridiculously fast at really low altitudes or not being able to take off and have to restart the game. http://imgur.com/D5v8WT2

[BudgetHedgehog]

That's a known issue with "Ferri". If you can nail down solid reproduction steps, ferram4 has an issue on Github you can contribute to. Quick question though - did you install FAR via the CKAN?

[MarvinCZ]

@gayski I'll just add, that while it is a "known issue", those reproduction steps are desperately needed. So make sure that you have FAR properly installed with its dependencies, and then try to reliably reproduce the bug with as simple a procedure as you can manage. If you do, make a report as decribed here.

[Dragon_Lance]

First of all, thank you Ferram and everyone else for your amazing work on this plugin. FAR takes KSP from a fun little game to the highest plateaus of time-suck

However, I've been getting bugged by a little bug (haha) that I haven't seen reported anywhere in this thread.

Occasionally, when tweaking a spaceplane design involving the Mk2 cargobay I will find that the center of lift will become unbalanced to the left or right. This causes the plane to go into a constant roll on launch. It only seems to come up when optimizing the Mach 1 Wave drag-area below approximately 2.5.

I have tested this on a clean install with only FAR installed (dev version 3a0b0b5987) and I've built an example craft that displays this behavior. This plane will roll constantly to the right on launch, until you raise the gear. Then it flies perfectly level. However, on my main install I have been able to build craft that do this with gear up or down.

Here is a link to the craft file and my output log. https://drive.google.com/folderview?id=0B90Kqpp-VQCqfm11TWo1U3Zoc3QtMVB0M2FGbHdrdmU5VWF4QjNSTUszVlh2RzNlRVl6Tmc&usp=sharing

Thank you again for doing such great work.

[sashan]

Gimbal is your friend:

Yeah, thanks. Found out that Skipper has puny three degrees of gimbal range. ModuleManaged it to 6 and it flew like charm. After all, real engines have similar range. In addition, MechJeb's corrective steering should never be enabled with FAR.

Now I always check pitch stability. If it is just plainly unstable then I work further on a design. If it is unstable with oscillations, I know that it can be counteracted with gimbal.

Also, stock SAS it much better with FAR than MechJeb's smartASS. And yes, I've tried tuning pids.

Edited June 2, 2015 by sashan

[Ryds]

Hello,

I've just noticed this problem that leads to my crafts flipping on ascent. The CoL moves unexpectedly as the fuel tanks drain. I've uploaded four pictures that show it moving when I drain the tanks in the VAB.

I had over 50 mods installed when I noticed it and through process of elimination narrowed it down to FAR. These screenshots are taken from a clean install of KSP with FAR as the only installed mod.

Reproduction

Ubuntu 14.04

KSP 64

Ferri 0.15.2

Player Log

http://www.filedropper.com/player

Mk1 Pod

Any Fuel Tank

Any Engine

Any Wings

Full Tank

Empty Tank

Full Tank + Wings

Empty Tank + Wings

Thanks!

[Gryphon]

Hello,

I've just noticed this problem that leads to my crafts flipping on ascent. The CoL moves unexpectedly as the fuel tanks drain. I've uploaded four pictures that show it moving when I drain the tanks in the VAB.

When this happens, how fast are you going (airspeed, mach, and dynamic pressure), and at what altitude? Also, are you making a turn or flying straight?

[Ryds]

When this happens, how fast are you going (airspeed, mach, and dynamic pressure), and at what altitude? Also, are you making a turn or flying straight?

Hmm, when the rocket flipped in my modded game I went back to the VAB to check CoL vs CoM and that's when I noticed the unexpected indicators. That rocket had parts from B9 (dev) and a load more. So...

I focused only on the moving CoL as the problem and found that a fresh install with only FAR showed that it still moved around but I didn't actually take a flight to see if it flipped! I've extensively tested the fresh install and indeed it doesn't flip, which is encouraging but the CoL still moves around as the pictures show.

It appears then that it is another mod, probably B9, not playing well with FAR, which figures as it's not finished but the CoL in the VAB on the FAR only install still wanders. The flight characteristics of the fresh FAR only install are within the expected range.

Thanks tho and let me know if you need any more info/items re the wandering CoL, I probably won't post the flipping rocket issue to the B9 thread as I'm sure they're well aware of it.

[ferram4]

@Dragon Lance: Probably related to errors in Ferri wrt voxelizing Mk2 parts. Should be fixed in the dev build.

@Ryds: Looks like it's just a CoL indicator issue, especially because for what you're saying is the issue to occur, voxelization would have to occur mid-flight... which it doesn't. It's just one more in the list of, "the CoL is damn useless" issues, and the problem is really that your rocket is unstable. Aerodynamic forces do not change based on mass changes because that would be dumb and add more calculations to be dumb.

[jrandom]

I maintain that the CoL indicator is useful for getting a rough idea of where it's located (good for wing placement during the initial design phase before fine-tuning) and would be a great tool if the FAR panel had pair of AoA/Mach sliders you could move around and watch the CoL update in realtime. Kerbal is all about fast iteration of whatever crazy ideas you have and this one small addition would be a great visual tool with immediate feedback.

[Vegatoxi]

How to disable AD faliure?

My planes crash into pieces even at little overG, it's stupid.

Supermaneuverability? Didnt hear.

[steve_v]

In the FAR debug menu, accessible from the toolbar icon in the space centre view.

[Bakase]

How to disable AD faliure?

My planes crash into pieces even at little overG, it's stupid.

Supermaneuverability? Didnt hear.

If you're designing anywhere near sensibly, you shouldn't be getting that kind of failure. Supermaneuverability is perfectly achievable in FAR.

[Granen]

Just installed FAR and started a new career.

During my first orbit flight i had some trouble when i was returning to kerbin.

For some reason i don't slow down during the descent, i ended up hitting the ground at 2000 m/s.

Anybody know the problem?

[Svm420]

@Ferram

The Tantares mod as an issue where the engine fairing don't show up under voxelization. It as if there are not there I have a post detailing here. I know this is a part makers issue to fix not yours and I have let the author know. What I am coming here for is the author needs guidance on what changes to make for compatibility his post is here. If you would either let me know or let the author know directly what changes to make. Thanks!

If anyone knows the answer please let me know!

[Jovus]

Is anyone else having some trouble making stable reentry vehicles?

Specifically, I'm using 1.25m parts, and it seems that the limit of what I can call stable is a Mk1 capsule with a 1.25m payload bay underneath. Anything more, and it requires SAS to keep properly oriented, or worse, goes point-first regardless.

This isn't a complaint or a bug report. Rather, it seems the new changes have pointed out a flaw in my designs, and I'm looking for advice on what to do if I want to return anything more than just a capsule (without using a spaceplane). For example, has anyone found a way to bing back 3 Science Jr's? (I'm using Deadly Reentry as well.)

I can provide pictures if that would be helpful.

[jrandom]

Is anyone else having some trouble making stable reentry vehicles?

Specifically, I'm using 1.25m parts, and it seems that the limit of what I can call stable is a Mk1 capsule with a 1.25m payload bay underneath. Anything more, and it requires SAS to keep properly oriented, or worse, goes point-first regardless.

This isn't a complaint or a bug report. Rather, it seems the new changes have pointed out a flaw in my designs, and I'm looking for advice on what to do if I want to return anything more than just a capsule (without using a spaceplane). For example, has anyone found a way to bing back 3 Science Jr's? (I'm using Deadly Reentry as well.)

I can provide pictures if that would be helpful.

Best advice I've encountered to date: Airflow in the VAB is modelled as flowing downward from the roof, so turn on CoM and CoL markers and flip your reentry vehicle upside-down in the VAB (to properly orient it to the airflow it would experience during reentry) and doublecheck that the CoL is not closer to the heatshield side than the CoM.

[Jovus]

Yeah, I know the tricks. I was less asking, "How do I tell?" and more, "I have designs that I know don't work, because I've tested them, but they used to, so I'm looking for new ideas because I'm obviously in a design rut if others aren't having this problem."

I appreciate the advice, though.