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

[ferram4]

@ayana: You still haven't told me which cargo bays are causing the problem, which means that I can't reproduce the bug, which means that I can't fix it. There was a reason I asked what cargo bays you were using.

@thorfinn: I suppose I could do that... It'll just end up being something else on top of the current deflection parameters. Only problem is that it's likely to break compatibility with planes made in old versions, and then I get to hear all the complaints from that.

@Razorcane: Older versions are available from the mediafire folder link in the first post of this thread for that exact purpose. However, you're going to be limited to anything 0.12+ if you want to use the SPH or VAB without things locking up, and you're going to be limited to 0.12.2+ if you don't want game-breaking bugs in flight. If you want to get rid of minor bugs, you'll need to use 0.12.5.2, since all the other versions have issues.

That said, your problem is having too high a TWR. Fewer engines, thrust limiter, throttle: use them. Using early versions of FAR will not get rid of these issues, and may simply exacerbate them; your designs need to change.

[Hodo]

Is there any way I can get an older version of this plugin? Both the latest and experimental version of the plugin make career mode unplayable. Without wings on my rockets, the rocket loses control and flips upside down. With wings, rockets cannot turn within the atmosphere (below 30k). It's really hard to play early career mode, since I can't actually get anything into orbit.

Does your rocket have to much TWR?

Are you performing your gravity turn to late or to steeply?

Is the top of your rocket far heavier than the bottom?

Is the top of your rocket about as aerodynamic as a barn?

If you answered yes or maybe to any of the above questions, it wont matter what version of FAR you are using.

[Phoenix84]

Does your rocket have to much TWR?

Are you performing your gravity turn to late or to steeply?

Is the top of your rocket far heavier than the bottom?

Is the top of your rocket about as aerodynamic as a barn?

If you answered yes or maybe to any of the above questions, it wont matter what version of FAR you are using.

I was having this problem myself. My rocket payload was over 100 tonnes.

I would do the quick tap to initiate the gravity turn at about 2km, and try to let it do its thing. However the rocket would do one of two things:

1) turn too far and the prograde would dip below the horizon.

2) After lower stage separation, it would flip over.

I found I had to do the following to get it in orbit:

Launch straight up until the larger SRBs burn out (stock). This was at about 7km.

Start turning slowly, making sure my heading didn't stray too far outside the prograde marker.

Once I reached about 30km (around 45° at that point, IIRC), then I could start taking care of my target apoapsis.

I also had to take care and make sure I was pointing towards my prograde marker during stage separation.

[Razorcane]

Does your rocket have to much TWR?

Are you performing your gravity turn to late or to steeply?

Is the top of your rocket far heavier than the bottom?

Is the top of your rocket about as aerodynamic as a barn?

If you answered yes or maybe to any of the above questions, it wont matter what version of FAR you are using.

1. No. The TWR is 1.38.

2. No. I'm performing my gravity turn at around 5km. Or rather, I try to, but I can't, because of the aforementioned issues.

3. No. Is that even possible? The center of mass is within the confines of the first stage.

4. I don't know what you mean by that, but I'm using the Mk-1 Pod and the starter parachute only. However, below it, I do have two of the mystery goo units attached to a science jr.

@Razorcane: Older versions are available from the mediafire folder link in the first post of this thread for that exact purpose. However, you're going to be limited to anything 0.12+ if you want to use the SPH or VAB without things locking up, and you're going to be limited to 0.12.2+ if you don't want game-breaking bugs in flight. If you want to get rid of minor bugs, you'll need to use 0.12.5.2, since all the other versions have issues.

That said, your problem is having too high a TWR. Fewer engines, thrust limiter, throttle: use them. Using early versions of FAR will not get rid of these issues, and may simply exacerbate them; your designs need to change.

My TWR is 1.38. If that is too high, then I don't know what to do. I only just started a new career mode, so I only have two engines. The LV-909 isn't powerful enough for a first stage, and the LV-T45 is what provides the TWR. I could add another tank, but at that point it is rather tall and lanky (1.25m parts and about 20-25m tall). This isn't a problem later in the tech tree, regardless of my TWR.

[ferram4]

Ah. I see the problem: 5 km is way too far up to start a gravity turn with FAR. Try when you're going between 50 and 100 m/s, whatever altitude that the rocket is at when that happens. 5 km starts are for TWRs of 1.1 in RSS and for standard rockets in KSP sans FAR.

[Razorcane]

Ah. I see the problem: 5 km is way too far up to start a gravity turn with FAR. Try when you're going between 50 and 100 m/s, whatever altitude that the rocket is at when that happens. 5 km starts are for TWRs of 1.1 in RSS and for standard rockets in KSP sans FAR.

That seems to work alright, however when aiming for a 90 degree inclination (or roughly), it spins and moves to the left when I push down (which puts me on a proper heading).

Edit: Nevermind. I lose control of the ship at about 15km.

Edit 2: Let me be more specific. After doing two more tests of trying to get into a 90 degree orbit, here is exactly what happens. At 1.5km, I start my gravity turn. I push W to turn towards the proper heading. However, instead of doing so, it starts spinning, and moves towards the left. It is really the most frustrating thing I have ever encountered. The reason I was asking for an older version is because I didn't have this problem in any .11 release.

Edited March 23, 2014 by Razorcane

[ferram4]

Well, that sounds like either your vehicle is aerodynamically asymmetric or there's a bug; a picture would be helpful in determining which it is.

All of that said, you can install one of the 0.11 versions, there's a link to a mediafire folder with them in the first post of the thread, but you won't be able to use the editor at all unless you downgrade to KSP 0.22.

[ayana]

I've seen the strange shielding behavior on the cargo bays in these two mods. Just radially attach anything to the sides. Batteries or solar panels.

http://forum.kerbalspaceprogram.com/threads/57662-PorkWorks-dev-thread-Inflatable-habs-and-more!-Current-project-MK2-stock-expansion

http://forum.kerbalspaceprogram.com/threads/68429-0-23-Kerbin-Shuttle-Orbiter-System-v2-06-aka-Kerbin-Mini-Shuttle

[SSSPutnik]

I've seen shielding behavior on LLL fairings. Items attached to it on the outside show as shielded....

[DaMichel]

Thanks Ferram4.

Then those PWing parameters made totally sense for beeing twice as long as a stock control surface. A PWing analog of a single stock control surface does indeed behave like one.

[thorfinn]

I have noticed a minor bug in the 0.13 experimental: after decoupling a tank from a shuttle, all the debris parts got labeled as shielded. If one switches to the tank, it is unaffected by atmo drag, but drag comes back if the craft is unloaded and reloaded. It is repeatable (you might notice that the pictures refer to two different tanks)

I should add that the .craft file is mostly from 0.12.whatever, but one part was added in the VAB after 0.13 was installed.

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Edited March 23, 2014 by thorfinn

[a.g.]

I have noticed a minor bug in the 0.13 experimental: after decoupling a tank from a shuttle, all the debris parts got labeled as shielded.

This is because the experimental recomputes the cargo bay shielding when the vessel is modified (which is reasonable), and this allows some previously existing code to trigger. That code is applying cargo bay shielding to other vessels, and in doing that it uses only the position of the root part. When you decouple, the root part of the debris is the decoupler, and if you look closely, that part is shielded even before decoupling, because it marginally clips into the bounding box of the bay. Then, when it becomes the root of another vessel, it is propagated to all the parts.

[thorfinn]

Beautiful explanation, thanks. By "previously existing", you mean stuff carried over from .12?

[a.g.]

It was there all the time, but previously decoupling didn't trigger a recomputation so it wasn't called at this moment in time. I think I added recomputing on vessel change in one of my patches, because otherwise it didn't update shielding when you added and removed parts in the editor.

Basically it's the same general issue of cargo bays shielding parts attached to them from the outside, only made even more spectacular by the way it handles whole vessels.

Edited March 23, 2014 by a.g.

[Razorcane]

Well, that sounds like either your vehicle is aerodynamically asymmetric or there's a bug; a picture would be helpful in determining which it is.

All of that said, you can install one of the 0.11 versions, there's a link to a mediafire folder with them in the first post of the thread, but you won't be able to use the editor at all unless you downgrade to KSP 0.22.

I don't know which it is, but like I said, I don't have the problem later in the tech tree, when I unlock SAS. I still find it annoying that all of my rockets require wings (because that's incredibly unrealistic), but it's better than not using FAR at all. Here is an image of my rocket.

[ferram4]

@Everyone with cargo bay issues: I'll look into it. I've got some things that I think might help make it work better, but that requires some testing. A lot of it has to do with parts that are radially attached to thinks have their origin at the attach point, and FAR determines shielding based on that point's location. I think I can do something more sophisticated though.

@Razorcane: Well, your rocket has no thrust vectoring, and real life rockets have a lot more thrust vectoring than KSP rockets, so the need for fins is to be expected. Even with the Goo Canisters on the top, it should be fine. The only reason that thing should be twisting is if you manage to get an asymmetric stall on the fins, which should only happen if you bring your rocket something like 15 degrees off prograde. There's no antenna hidden on the other side, right? Because that could mess things up.

[federicoaa]

In my experience, having fins like that makes my rocket spin out of control.

[ialdabaoth]

Ferram: I now have a working full-replacement for the stock heat system. It's going to replace Deadly Reentry.

However...

Could I get your help with some formulas?

[LordOfTheOrbits]

Ferram: I now have a working full-replacement for the stock heat system. It's going to replace Deadly Reentry.

However...

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

Could I get your help with some formulas?

If you don't know the formulas you need, why don't google them? There's way too many things you need to know about thermodynamics to explain it completely in this thread. Also, why are you making a mod that does something that is already implemented nicely by another mod?

[Xechran]

If you don't know the formulas you need, why don't google them? There's way too many things you need to know about thermodynamics to explain it completely in this thread. Also, why are you making a mod that does something that is already implemented nicely by another mod?

I wonder if you realize that Iad is the guy who maintained DRE? Hes not coming in out of the darkness here.

[ialdabaoth]

If you don't know the formulas you need, why don't google them? There's way too many things you need to know about thermodynamics to explain it completely in this thread. Also, why are you making a mod that does something that is already implemented nicely by another mod?

When I say "I have no idea what I'm doing" / "I need some help with some formulas", I'm speaking at ferram's level, not at n00b level.

To be more specific:

"I need a good set of equations such that, given a Part with assumed uniform density and composition, with specific heat C, mass m, thermal conductivity K, and temperature T, travelling at velocity v through air with density d and static temperature T(atm), describes the dT/dt that the part should experience from a combination of convection and shockwave heating. Also, I need another good equation for the dT/dt that that part should experience (and the dT'/dt' that its neighboring part should experience), given a contact surface between those parts of A square meters and a distance of x meters from their centers of mass. These equations invoke surface area and exposure to atmosphere, which FAR already handles, so I thought I'd ask you instead of reinventing the wheel."

What I current have is a bit of a hack (but still a bit better than stock KSP's heat system); I want something at FAR's level of accuracy.

Edited March 24, 2014 by ialdabaoth

[JewelShisen]

I am wondering if you would be able to take a look at some of the parts from ID's new Skillful mod. I have noticed that some of the parts are creating far more drag than they should be, namely the 1.25m hull shielding used for armoring the underside of a plane.

Thank you much and keep up the awesome mod!

[LordOfTheOrbits]

When I say "I have no idea what I'm doing" / "I need some help with some formulas", I'm speaking at ferram's level, not at n00b level.

To be more specific:

"I need a good set of equations such that, given a Part with assumed uniform density and composition, with specific heat C, mass m, thermal conductivity K, and temperature T, travelling at velocity v through air with density d and static temperature T(atm), describes the dT/dt that the part should experience from a combination of convection and shockwave heating. Also, I need another good equation for the dT/dt that that part should experience (and the dT'/dt' that its neighboring part should experience), given a contact surface between those parts of A square meters and a distance of x meters from their centers of mass. These equations invoke surface area and exposure to atmosphere, which FAR already handles, so I thought I'd ask you instead of reinventing the wheel."

What I current have is a bit of a hack (but still a bit better than stock KSP's heat system); I want something at FAR's level of accuracy.

Oh sorry, I didn't realize that you were the dev of deadly reentry 2. Well then I'm looking forward to the update that will implement this!

[NWM]

Nice work Ferram!

At hypersonic speed the main diference is a changed row of the turboojet in the config file - turbojets can't fly faster than 1500m/s and higher than 30,000m-s. The stabity loss is small.

The main difference is balance changing at lower speeds. The most critical change happends after breaking trough the sound speed. It is almost impossible to lift up the nose even of those aircrafts, which flied through the sound speed loosing only some hundred meters... Even moving the CoM bacwars does'nt help...

Thank you much and keep up the awesome mod!

[Dirt_Merchant]

@ferram4: Very much enjoying the new release, I've no complaints or serious bugs to speak of at the moment, but I did want to revisit an idea I brought forth a few pages back regarding the control surface assignments. I have to admit that I absolutely deplore using the sliding tweakable menus to manipulate control surface deflections. I humbly implore you to at least provide the option for the use of the old style control surface assignment GUI page. That allowed me to do many things that I am no longer able to do, and it makes me a very sad tradesman of soil. Also, please, split aileron drag rudders that i can operate with my joystick instead of the action groups i used for the craft below.

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I submit this request with not but the utmost respect, and indeed gratitude!

Sincerely,

The merchant prince of dirt *bows and curtsies, drops mic, walks off stage left*

Edited March 26, 2014 by Dirt_Merchant
cleaning for hodo, thank you for the tip!