[1.2] Procedural Fairings 3.20 (November 8)

[mecki]

Requests:

• Tweakable (enable/disable) decoupler for the interstage fairing base (top-node, not on the base itself)
  
• Tweakable base-heights for all the fairing bases (sometimes it looks not so nice with default heights)
  

*sign*

I even would like to have (tweakable) decoupler on all fairing bases… And a raised interstage fairing base.

[DavidHunter]

Never knew that log even existed. Thanks! Will try and trip it up tomorrow.

Ignore me. I'm a f---wit.

Turns out I was running KSP v0.24.0 instead of v0.24.2. Facepalm.

All working now.

[Threadsinger]

Hiya guys,

Newbie question here (and I did make a reasonable attempt at a search):

During launch, the payload often bends internally under some kind of load and emerges from the fairing, breaking apart the craft and killing everyone in a 10 kilokerbal radius. Pretty, but not very useful.

Is this (incredible!) mod supposed to let that happen? Am I putting too much thrust at launch? Is there a way to tell if what's inside the fairing is actually being ignored by whatever aerodynamic process the game is running? I don't know much about programming or how these mods work, but I'm silently praying that it's some simple fix or incompatibility that one of the legion here has encountered before.

I do have the most up-to-date version of this mod, and I have tried it with the stock game and that NEAR mod (ferram?) to troubleshoot. I am using a few mods, ones I believe are very popular and used in that Interstellar Quest series on Youtube (so I hope someone here might have them), but I'm more hoping this is a simple problem easily fixed.

Thanks to the mod creator for such a great setup, and to all for your kergineering advice!

[dzikakulka]

@Threadsinger - I have a similiar issue, my fairing seems to be very wonky on the bottom, breaking off on more that few degrees prograde tilt at 150-250 m/s. You can see if parts are "shielded" only in FAR (NEAR has all gui removed), place one part of fairing in vab and everything under (even with 1/3 fairing for now) should have isShielded = true flag on right-click. In flight you can right-click fairing and it will tell you how many parts is it shielding. BUT for me even despite all these values look fine I still get my fairing ripped off sometimes. I get that's simply because it's only rigid on the bottom where it's connected and I can't really do anything about it but if you'll figure anything out to make it harder to break, please share!

I'm experimenting with other, more rigid means of payload transport (TalisarCargo at the moment) and maybe that will have better stability.

Edited August 11, 2014 by dzikakulka

[Threadsinger]

@Threadsinger - I have a similiar issue, my fairing seems to be very wonky on the bottom, breaking off on more that few degrees prograde tilt at 150-250 m/s. You can see if parts are "shielded" only in FAR (NEAR has all gui removed), place one part of fairing in vab and everything under (even with 1/3 fairing for now) should have isShielded = true flag on right-click. In flight you can right-click fairing and it will tell you how many parts is it shielding. BUT for me even despite all these values look fine I still get my fairing ripped off sometimes. I get that's simply because it's only rigid on the bottom where it's connected and I can't really do anything about it but if you'll figure anything out to make it harder to break, please share!

I'm experimenting with other, more rigid means of payload transport (TalisarCargo at the moment) and maybe that will have better stability.

Thanks dzikakulka, I think I'll go install FAR (gods help me) and look and see what it says.

It also just occurred to me that maybe the fairings are just too high and I need to learn how to use that "clip-at-the-top" fairing part...

I dunno, I'll experiment and see what's what.

[Pecan]

Fairings are puely cosmetic in stock KSP - they'll only 'shield' things with NEAR/FAR. They will not brace the contents against acceleration so any wobbles they have will require struts.

[Threadsinger]

Fairings are puely cosmetic in stock KSP - they'll only 'shield' things with NEAR/FAR. They will not brace the contents against acceleration so any wobbles they have will require struts.

Thanks Pecan!

[DavidHunter]

Thanks dzikakulka, I think I'll go install FAR (gods help me) and look and see what it says.

It also just occurred to me that maybe the fairings are just too high and I need to learn how to use that "clip-at-the-top" fairing part...

I dunno, I'll experiment and see what's what.

I didn't bother reading the replies, so I'm probably repeating them, but...: your issue is going to still happen with FAR. FAR just shows you if you've got a large angle of attack (the angle between the direction your rocket is facing and the prograde direction - that is, the direction your engines are pushing you... note that they are different directions!)... and FAR also changes the game's normal aerodynamics.

What you want to do is keep your angle of attack low (the FAR toolbar shows AoA), i.e. less than 10 degrees, while in any atmosphere. Otherwise, the force of the air being pushed into the top of the rocket (as it rises through the atmosphere) pushes the top of the rocket sideways and rips the top of it (in your case, the fairings section) clear off the rocket boosters.

To further explain AoA... suppose you launch straight up. Your prograde direction is then straight up.

Then you tilt over to 45deg.

At the moment you tilt over, your AoA is the difference between prograde (at 90deg, straight up) and the direction the rocket is facing (45deg), i.e. 90-45 = 45deg. This is an extreme AoA. You want to keep it generally under 10deg, although differently-shaped rockets with different parts can handle different AoAs.

Anyway, after doing the tilt to 45deg, the prograde direction slowly moves down toward the 45deg angle the rocket is pointing to.

So with FAR installed, it's best to make small tilts early in launch, then gradually tilt over.

What I typically do is (you can fine-tune these values for each rocket):

0-800m ASL: straight up.

800m-3km: 88deg pitch. (Using MechJeb's SmartASS module can help for precise steering).

3-6km: 86deg pitch.

6-10km: 83deg pitch.

(note that with the above turns, maximum AoA will only ever be 3deg - between 6-10km ASL when I change from 86 to 83 deg pitch).

At this point, you've cleared the thickest part of the atmosphere, so AoA isn't as delicate and you can start doing steeper tilts. It is, though, still important, so be careful.

10-15km: 80deg pitch.

15-25km: 70deg pitch.

25-30km: 60 deg pitch.

30-35km: 50 deg pitch.

(now through most of the atmosphere, pitch change can be made even steeper)

35-40km: 40 deg pitch.

40-45km: 10 deg pitch.

45-50km: 0 deg pitch (assuming, of course, you have enough thrust to get your apoapse up to the correct altitude. If not, then pitch upwards instead).

50km-80km: before this phase, I usually burn so my apoapse is 10-15km higher than my desired orbital height. During the 50-80km phase, I would typically burn while pitched varying between -25deg and +2deg. That way I can circularise the orbit during initial ascent (rather than having to restart engines for a separate circularising burn).

Edited August 12, 2014 by DavidHunter
Added explanation and launch pitches

[dzikakulka]

David - I did not turn 45 degrees at some altitude, that would be just impossible. I was trying to stay ay ~1-3 degrees AoA but fairing would rip off even at simply going prograde due to forces acting on it and weak rigidity at base. I gues it's no aero monster but I think it should be quite stable.....

[taniwha]

dzikakulka: Oh good grief, just what is the TWR on that thing? It must be utterly insane. You want 1.2-1.8 while in atmosphere. It also looks unstable: low CoM, high CoL. You want high CoM and low CoL (use the indicators).

[dzikakulka]

I know, I never burn it at max throttle. I maintain max 200m/s in atmosphere which means ~1/3 thrust, ofc mainsail off. CoM ain't that low, there's bunch of LV-Ns, large RCS tank and other stuff in fairing (reentry-able mobility module for space station). CoL too high? You mean center of thrust? Is it that bad?

Edited August 12, 2014 by dzikakulka

[Master Tao]

dzikakulka,

taniwha did mean CoL*, not CoT. You want your CoL behind/below your CoM, just like you do with planes or it will tend to flip end over end. You might be able to shift it far enough with fins near the bottom, but you'll probably have to make the whole rocket taller and narrower, too.

*soon to be officially renamed aerodynamic center

[DavidHunter]

David - I did not turn 45 degrees at some altitude, that would be just impossible.

Perhaps not with that monster rocket. '

Hmm, such a shallow AoA should be fine... have you tried adding struts from the top of the four radial boosters onto the fairings? That might give it some more structural integrity... also, strutting from the upper-half of the radial boosters to the inner core booster will most likely be needed, too.

[DavidHunter]

dzikakulka:You want 1.2-1.8 while in atmosphere.

I regularly use TWRs in excess of 5 during launch without issue. Just don't have any Kerbonauts aboard.

[dzikakulka]

Oh damn, now I get you. That's how I check if .... won't flip over. Was so clueless, thanks taniwha and Master Tao

[Threadsinger]

I didn't bother reading the replies, so I'm probably repeating them, but...

Thanks David! That's some good knowhow and I will put it to good use to make efficient, "gentle" burns. I should clarify it's not the fairings that are getting ripped off - it's what's inside... I assumed the fairings were a "hard shell" (so the payload can't "leak" out), but I realized after some trial and error the internal payload is probably not stiff enough, so just the thrust alone from the engines is knocking the payload out of balance and causing it to clip out of the fairing... which then catches the "air", which then kills the rocket.

dzikakulka: Oh good grief, just what is the TWR on that thing? It must be utterly insane. You want 1.2-1.8 while in atmosphere. It also looks unstable: low CoM, high CoL. You want high CoM and low CoL (use the indicators).

Good advice. I always assumed low CoM. I'll play with that too. A little challenging with KSP-I (in my save, I've just unlocked basic fusion engines, and their TWR with enough atmosphere intake is borderline mass-driver ish..) but fun to work out.

[M3Man03]

After researching all the fairing bases, I still only see the tiny one in my Aero section. How come the rest don't show up? They are listed as "owned" in the research building.

[Master Tao]

M3Man03,

Try right-clicking on the fairing base. You should be able to change the size by tweaking them. If not, you probably need to update any mods from this list.

If that doesn't work, there is important information to include in any bug report:

• Your KSP version
  
• Your mods and versions (if any)
  
• Your Operating System and version
  
• Steps to cause the problem
  
• Cause the problem, then quit KSP and find your output log:
  
  • Windows (32 bit): KSP_win\KSP_Data\output_log.txt
    
  • Windows (64 bit): KSP_win64\KSP_x64_DATA\output_log.txt
    
  • Mac OS X: Open Console, find Unity on the left side, and click on Player.log. It's also located at ~/Library/Logs/Unity/Player.log.
    
  • Linux: ~/.config/unity3d/Squad/Kerbal\ Space\ Program/Player.log
    

[DavidHunter]

After researching all the fairing bases, I still only see the tiny one in my Aero section. How come the rest don't show up? They are listed as "owned" in the research building.

I bet $30 you're running KSP v0.24.0 rather than v0.24.2. That was exactly the issue I had but didn't realize I had the wrong KSP version. Check the lower-right corner of the screen when you first load KSP (in the main menu).

- - - Updated - - -

Perhaps not with that monster rocket.

Well... you could do it with enough RCS thrusters.

- - - Updated - - -

You want your CoL behind/below your CoM, just like you do with planes or it will tend to flip end over end.

Did not know this. Thanks!

[Andrewmacor]

Is it just me or the problems with the fairing separation still going? also the KSPAPIExtentions.dll still showing as incompatible.

[Master Tao]

Andrewmacor,

Try updating your mods. You have outdated versions.

Edit: That, or you have an outdated version of KSP.

Edited August 13, 2014 by Master Tao

[rhoark]

Is it possible to KAS ejected fairings back into place?

[Master Tao]

You could try adding a KAS module to the fairing part configs, but I see a few potential problems with that:

• Kerbals carrying large objects become extremely difficult to control.
  
• KAS part placement is finicky even with normal parts.
  
• I don't know how KAS handles procedurally generated parts.
  
• I have no idea whether FAR/NEAR or even DRE will respect replaced fairings.
  

So... take a look at other parts with KAS modules and try to put something appropriate in the fairing configs. Then report back how awesome the explosions were. Pictures, please.

[Renegrade]

Just wanted to add my thanks for this excellent mod. The recent changes (thrust plates, tweakable fairings/tweakable faring base scale/scale unlock support, etc) are all especially nice.

Kudos, and thank you very much!

[Starwaster]

You could try adding a KAS module to the fairing part configs, but I see a few potential problems with that:

• I have no idea whether FAR/NEAR or even DRE will respect replaced fairings.
  

They use raycasting to detect the fairings, or at least DREC and FAR both do. I assume NEAR does as well or fairings would be no good with it.

(DREC will not do its own raycasting if it can detect and query FAR to determine shielded status)