ferram4

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

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I an having difficulties to port my Rocket SSTO with hot landing, to the FAR system, because it keep turning my rockets or point it to front fall. I try to put the back heavier, and use rcs to force position, but because the speed and forces are to much, i cant control my back fall, to them be able to made the hot landing. So i think in put aerobrakes on front of the rocket, and use it only on the descending, but this wont work. Appear to me that the FAR system is not for rockets, because it don't agree if the up position on things.

Look:

OFF

8697803017_44e6cc4018_o.png

ON

8698926220_50ef6e7c97_o.png8698926444_022649e011_o.png

Can this be fixed, so we will have a new use for the aerobrakes? on rocket too? will be marvelous!

Thank you By your attention Ferram4!

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With this mod planes are amazing. Quite honestly they're hard to take off, but they are simply amazing to control mid-flight. However I'm wondering if the effects on rockets is realistic, my super heavy launcher now goes to about 300-400m/s with the mod in stage 1 when before it only had around 150. Overall it's a little more efficient but nothing huge. I'm wondering if the faster speed is a realistic change and not just making the game easier?

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Hello,

I'd love to have this mod work for me, but I can't seem to get the Interface to appear no matter what I do. I read the rest of this thread and tried:

Double-checking the part.cfg for the cockpit I'm using has a call to the module.

I have no other mods installed and I don't have a PluginData folder. KSP.exe has Administrator rights so that shouldn't be an issue to create it. I did try creating one just manually, but it didn't help.

Any solutions?

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Hello,

I'd love to have this mod work for me, but I can't seem to get the Interface to appear no matter what I do. I read the rest of this thread and tried:

Double-checking the part.cfg for the cockpit I'm using has a call to the module.

I have no other mods installed and I don't have a PluginData folder. KSP.exe has Administrator rights so that shouldn't be an issue to create it. I did try creating one just manually, but it didn't help.

Any solutions?

I can try to help you, with TEAMviewer.

If you agree, send me a private message....

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I have determined FAR to be the cause of this:

http://www.youtube.com/watch?v=RX4bLs6H0dk&feature=player_detailpage

It spams "[Exception]:NullReferenceException: Object reference not set to an instance of an object" in the debug log.

The game is unplayable with FAR installed, how do I fix this?

Especially bad considering how much I've been enjoying using it.

I'm having the same here. Start an hour ago, after playing well a long time...

I did not made anything different, just from a moment to another , start the lag and never get out. now happens exactly like your video, first seconds work, then , lag...

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That is odd. Well I'd go thru the usual suspects first, video drivers etc. Secondly, is it all planes? I'd test out something simple first maybe, to see if it's physics processing or something else.

Climberfx, that's interesting but can't you just use the rockets with mechjeb to land? I just can't see any landing attempt ending well with control surfaces on a rocket like that.

Edited by mcbmaestro

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That is odd. Well I'd go thru the usual suspects first, video drivers etc. Secondly, is it all planes? I'd test out something simple first maybe, to see if it's physics processing or something else.

Climberfx, that's interesting but can't you just use the rockets with mechjeb to land? I just can't see any landing attempt ending well with control surfaces on a rocket like that.

Mcbmaestro, i made it work, putting control by control, and one half with positive value and other with negative. And the thing is without it, the rocket goes with nose down, because the cockpit weight and aerodynamic, but with these winglets on top, that i use with brakes when coming back, i managed to work and solve my problem. And have a aerobrake to help slow down too...

It got almost perfect.

Son i post a video doing the orbit and coming back.

And for the fps problem, is a bug of FAR with Debris. I put my config with zero debris and all come back to work again.

Edited by Climberfx

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@Climberfx: Yeah, the spoilers are intended for aircraft only, but I can look into making them angle properly for rockets as well. To be honest, I'd but the ASAS down near the bottom of the rocket to make it more rear-heavy when it runs out of fuel.

@AndreyATGB: Most real life rockets make it to supersonic speeds (> 300 m/s) before their first staging event; I think the vast majority go well into supersonic speeds before staging. The fact is that it is far more realistic to be going 300 m/s at 10 km up than 150 m/s; yes, it makes things a little bit easier in the dV department, but it makes things a lot harder in the ascent trajectory department.

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@ferram4: I have a question for you. In FAR model you used Prandtl lift-line theory to calculate lift and induced drag. But is it correct for low aspect-ratio, large swept wings which are common for supersonic flight?

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I use a modified version of Lifting-Line theory that accounts for low AR and wing sweep; it may not be absolutely perfect, but it's close enough for a game. The only thing it doesn't model is proper 3-D stalling of low AR wings, but I can approximate the effect enough that it is indistinguishable from the real thing.

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@AndreyATGB: Most real life rockets make it to supersonic speeds (> 300 m/s) before their first staging event; I think the vast majority go well into supersonic speeds before staging. The fact is that it is far more realistic to be going 300 m/s at 10 km up than 150 m/s; yes, it makes things a little bit easier in the dV department, but it makes things a lot harder in the ascent trajectory department.

I often have a hard time trying to pitch down before 30km because I'm moving too fast and the air pressure keeps me pointed up, and quit a few rockets have gotten reentry effects during ascent. Though usually not for long enough to explode. So I wouldn't really call it easier, just more fuel efficient. And the game is just as hard as it ever was when your not in atmosphere.

Did I mention that I suck at Mün landings?

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You want to pitch over somewhere below 10km; to be honest I tend to pitch over at 60 m/s at about 2 - 3km. If you do it right you should have a few moments of panic thinking that your rocket is going to plunge into the sea, and then it will accelerate enough that it'll head into space.

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Now, i need to rethink my Rocket SSTO Jet Hybrid family.

(http://forum.kerbalspaceprogram.com/showthread.php/26502-0-19-1-STAR-series-Turbo-Upgrade-more-effective-and-efficient%21-double-intakes)

(http://forum.kerbalspaceprogram.com/showthread.php/26542-0-19-1-STAR-Supreme-The-big-Mama-of-STAR-series-SSTO-VTOL-Orbiter)

Before i can get near orbit velocity only on the jets, and then do the final circularization on Nuke.

This is the sad part of FAR. It make the RAMJETS a lot weaker then before.

But the others parts is to dam amazing. Now i can fly near ground like a pro. I feel the jets working as they should...

Edited by Climberfx

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Well, I've got another question for ferram4 or anyone else in this thread who may be able to answer:

I recently installed the KerbX mod, and am trying to get the dragon capsule to work with FAR. So, I copied the FARControlSys and FARBasicDragModel Modules from the Mk1-2 Command pod to the bottom of the cfg file for the KerbX dragon pod part, then changed the drag type to override and set the default drag parameters to zero (as was done in the cfg files for all command pods that come with FAR). However, the pod does not experience atmospheric drag in any meaningful quantity. In a straight drop from 200,000 m, it continued gaining speed until about 16,000 m, at which point it lost 1 m/s of velocity and Deadly Re-entry blew it up. The isShielded:false indicator has shown up, so I know FAR is seeing it. Both Q and CD are reading as non-zero, non-trivial values in the flight information readout - I assume that the reference area is out of whack. I have made these modifications to other modded pods (FASA Gemini and the Dragon Rider mod), and it has worked there.

Thanks!

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It sounds as if the surface area (S) for the part is the wrong size; make sure you copied that value over. If that's not the case, then make sure that the KerbX parts are using the same units for mass as the stock and stock-compliant parts (such as KSPX, NovaPunch, KW Rocketry, etc.). It's quite possible that they're using mass to kilograms instead of tonnes.

If that doesn't work, post a copy of the config file. I honestly don't know how big the pod is, so I can't tell you what the surface area should be.

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The size is fairly comparable to that of the Mk1-2 pod, however, it is greater (not greater enough to cause the magnitude of not-accelerating that I am seeing, I think). Here is a picture comparing the two:

screenshot42_zpsde59ed69.png

And here are the cfg files:

KerbX Dragon

Current Mk1-2 Command Pod (I've edited a bit, and it still works fine)

If you have any suggestions for me to try, things you want me to play around with, or anything else you want from me that might help you figure out what is going on, feel free to ask! And I'm an Aerospace Engineering student minoring in Computer Science, so technical is ok :).

Thank you for your time!

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If it was just a straight drop from 200 km then it might be acting properly; everything I'm seeing in the configs is correct, though I'd bump up surface area a little, maybe to ~18 - 19 m2. Try doing the same type of test using a Mk1-2 pod and see if it behaves the same; it's possible that gravity is overpowering aerodynamics that high up in the atmosphere and Deadly Reentry is melting you too soon.

Try bringing the Dragon in through a proper orbital reentry (as opposed to a drop) and see if it works properly.

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Here are the results from my test:

KerbX Dragon actual Re-entry test (no cfg changes from above):

Entry Speed to atmosphere from 280 x 30 km orbit (relative to surface): ~2300 m/s

Speed @ 40 km (relative to surface): ~2325 m/s

Speed @ 35 km (relative to surface): ~2319 m/s

Speed @ 30 km (relative to surface): ~2235 m/s

Speed @ 28 km (relative to surface): ~2184 m/s

Speed @ 26 km (relative to surface): ~2120 m/s

... At which point I surpassed the thermal limits of the ship. It is interesting to note that, when most of my ships fail from re-entry, they fall sort of all-at-once, going from a few thousand degrees to the 50k I have set as a limit very quickly. This guy just sort of gradually moves up to the threshold and explodes.

While it was feeling the effects of the drag for sure, it was much, much less than it realistically should be. It should be noted that I flew it in with the docking port and three parachutes attached. The entire contraption massed at 6.49 tonnes, as opposed to the 4.75 tonne re-entry mass of my Mk1-2 Pod + Heat Shield + Docking Port + Parachutes assembly. Perhaps S or CD simply need to increase for this pod?

EDIT:

I did the drop test from 200 straight with the Mk1-2, and you are right, the behavior of little to no slowing followed by a sudden flash of acceleration (and destruction) is the norm. Although Jeb was piloting the test, so that may have had something to do with the explosion.

EDIT 2:

Results from running the Mk1-2 through the same trial as the Dragon (Entry from a 300 x 30 orbit)

All speeds relative to the surface:

@ 70 km: 2250 m/s

@ 60 km: 2280 m/s

@ 50 km: 2314 m/s

@ 45 km: 2325 m/s

@ 40 km: 2321 m/s

@ 35 km: 2275 m/s

@ 30 km: 2080 m/s

@ 28 km: 1960 m/s

@ 26 km: 1820 m/s

... And so on with smooth sailing. But that data isn't really relevant for comparison, as this is the point where Dragon exploded. The Mk1-2 Pod made it down to the surface safe, and with a peak temperature of 16,000 degrees (which occurred deeper in the atmosphere), less than 1/3 of the temperature that Dragon got at nearly the same speeds while still 26 km up.

However, the accelerations seem to hold the same proportions between the two capsules, which makes me think drag simply needs to be scaled up for Dragon. If I were to do this, what would the best way to do this within FAR?

Edited by DresCroffgrin
Additional Information

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I'd just increase the surface area parameter for the Dragon proportionally to be honest; it's the most reliable way of increasing drag. Considering it is larger than the Mk1-2, this seems to be proper, though reducing the mass of the Dragon might be appropriate, considering it has an empty mass of 4.9 tonnes plus however much monopropellant it's carrying; I'll bet that monopropellant on board is part of the problem. I'd reduce the mass a bit and increase the surface area to make things work out.

Also, the Dragon's behavior with respect to heating might be explained by it's larger mass if Deadly Reentry accounts for a greater mass of material that needs to be brought up to temperature.

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Ferram4, you think in restore the power we have on stock KSP on higher grounds with extras intakes? Like after i got 2200 km orbit, now i only get 1400 km orbit speed.

And needed to put extras intakes for that, and extra jet.

So, i think the underpower is to much.

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I tried this mod out and all it seemed to do with my rockets is to make them more unstable, if anything performance dropped rather than increased, however the FAR stock rockets seemed to perform amazingly. Any suggestions of what might have gone wrong?

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I an having difficulties to port my Rocket SSTO with hot landing, to the FAR system, because it keep turning my rockets or point it to front fall. I try to put the back heavier, and use rcs to force position, but because the speed and forces are to much, i cant control my back fall, to them be able to made the hot landing. So i think in put aerobrakes on front of the rocket, and use it only on the descending, but this wont work. Appear to me that the FAR system is not for rockets, because it don't agree if the up position on things.

Look:

OFF

8697803017_44e6cc4018_o.png

ON

8698926220_50ef6e7c97_o.png8698926444_022649e011_o.png

Can this be fixed, so we will have a new use for the aerobrakes? on rocket too? will be marvelous!

Thank you By your attention Ferram4!

I figured out why my rocket won't come back straight after the far update (with back to direction velocity). Is because the edit in cockpits put then with zero values on drag, overwriting the original ones. Was not the weight because always my bottom part of the rocket was heavier.

But, because of that, it thinks the top is lighter on wing, even going backwards. Even Mechjeb couldn't manage to hold aim. So, i edit back the values on cockpits, and voila! All working again.

So, Ferram4, in my humbled opinion, this need a fix...

8704980400_e49dfa0395_o.png

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could anyone explain to me why would a plane decide to start shaking itself apart even before it lifts off properly? i've seen it happen while trying to fly the hypersonic speed thing and another design of mine that should take off, but they quite literally go "stable, stable, wings start catching air, have a seizure, fall apart"

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I tried this mod out and all it seemed to do with my rockets is to make them more unstable, if anything performance dropped rather than increased, however the FAR stock rockets seemed to perform amazingly. Any suggestions of what might have gone wrong?

This sounds about right. It is harder to build a good rocket, but a good rocket is more efficient. Do your homework and all will be well. It ads realism, you know :)

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