[1.1.2] Realism Overhaul v11.0.0 May 8

[Ravenchant]

Hey, people! Are there any parts missing RO configs that I could help adding? I'd like to contribute somehow, but programming is not my cup of tea, so...

Edit: Nevermind, I read the wiki =)

Edit 2: How does one remove engine shrouds via the Module Manager file?

Edited April 10, 2015 by Ravenchant

[plasmeus]

Hello, could anybody explain me how to properly launch a FASA saturn v? I always end up in a non-circular orbit (eccentricity at least 0.01) with at least 250 m/s of steering losses, and I am thus unable to perform a TLI.

Any help would be greatly appreciated.

Dolin

Dolin, you don't need a very circular orbit for a TLI so that shouldn't matter much. Pretty much no matter what you do I find that there is quite a lot of steering loss because the S-2 and S-IVB stages have low starting TWRs. In addition to that, the fuel tank mixtures are not correct, so I usually end up with extra fuel. Normally I would think this is to make up for LH2 boil-off, but there seems to be too big of a discrepancy between the fuel boil-off and extra fuel. The main thing to remember when launching the C-5 is to time your launch so that you line up with the plane of the moon.

- - - Updated - - -

NathanKell is right about the Hypergolics purpose as being storable. In fact, the the fuel mixture used for the LEM ascent stage was so volatile that the engine was ruined after only one burn. This meant that actual engines on the LEMs were not test fired which is why they had to be made so reliable.

Edited April 10, 2015 by plasmeus

[XkaOnslaught]

hey guys, just want to have some opinions on a issue i currently have:

i have been trying to build a minotaur one replica... and i think so far its pretty accurate mass and performance wise.... the only problem is that the first stage seems to be too powerful to the point my craft starts burning up at around 18km altitude. as far as thrust numbers go its the same as the actualy M55A1 solid stage... i am just wondering if this is currently a limitation of how DRE works right now? or it could be something else i am missing?

[plasmeus]

hey guys, just want to have some opinions on a issue i currently have:

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

i have been trying to build a minotaur one replica... and i think so far its pretty accurate mass and performance wise.... the only problem is that the first stage seems to be too powerful to the point my craft starts burning up at around 18km altitude. as far as thrust numbers go its the same as the actualy M55A1 solid stage... i am just wondering if this is currently a limitation of how DRE works right now? or it could be something else i am missing?

That tends to be the result of any launch with a high TWR rocket using default DRE settings. I get so frustrated with it sometimes that I often disable it. It is also too harsh on probes and structural parts in regards to G force tolerance, as in real life many probes were made to handle dozens, if not hundreds of G's.

[Friedrich Nietzsche]

Friedrich Nietzsche: does Testflight report a failure at that point? Check the rocket-ship icon. Ah, nm, later you said that was it. Make sure you air-light the LR-87s, as samroberts mentioned the Titans with SRMs did not ground-light their engines, they lit them on SRM near-burnout (like, 5 seconds left). The issue with TF is that engines have rated burn times, and if you exceed them they're likely to fail...might also ping Agathorn, maybe the LR-87s don't have enough rated burntime for the IIIL application (although if memory serves the widebody core didn't burn longer, it had more fuel and more engines).

The problem occured several times while simulating the rocket with Kerbal Construction Time. Shortly before shutting down, the failure rate number displayed by testflight increased (to still a very low percentage value). Then the engine turned off. This was also the exact message in the F3-Log. After removing Test Flight temporarily I was able to launch the rocket several times without problem. So I guess, it has to be Test flight.

It was the first time, that I had an engine failure, also it was very strange that it happended several times at the exact same time/location and in a simulation. So it took some time for me to get it. The strange thing is, that Test flight didnt report a failure in its window. Just an A-button appearded, I guess, it stands for "Activate", which doesn't work a second time with this engine.

The burn time could indeed be an issue. According to kerbal engineer, the burn time is up to 5 minutes, depending on tank utilization, which is almost two times more than that, what the stage should have (according the link from above)

Another issue, that I have with my rockets: What is a valid solution to reduce g-forces of 10 to 15 g near stage burnout? Do you put additional weight on the rocket, if the playload is to high? Or do you ignore such high g values, if flying unmanned?

Edit: I've also discovered, that RCS seems not to be influenced by the distance to the KSC. I can control the vessel in real time. Even though activating RCS takes a few seconds.

Edited April 10, 2015 by Friedrich Nietzsche

[NathanKell]

XkaOnslaught: I suggest using the M55 part that RO provides. It has a thrust curve, unlike the proc solid. Real solids don't generally maintain the same thrust throughout their burntime; thrust generally tails off. That will proportionally lower your TWR later in flight.

Friedrich Nietzsche: that's weird! I'd suggest posting about it on the TestFlight thread so Agathorn will be sure to see it. Regarding burn time--wait, it looks like you have only two LR-87s (i.e. one part) there? The Titan IIILs had four of them (two LR-87 parts)... IIIL2 link.

Regarding burnout Gs: you definitely ignore them if flying uncrewed. I'd suggest looking at the last few pages of the Real Fuels thread for a discussion of this issue. However, if you're hitting 15Gs at burnout, just how tiny an upper stage are you using? (I assume that's first-stage burnout). Or is it at booster burnout?

[Oksbad]

Oksbad: there's a lot that goes into making an engine restartable. First, has the high temperature melted anything you'll need again? Second, is the combustion chamber (or nozzle) now so ablated it's not safe to reuse? Third, how do you start up the turbopump, if there is one? Not needing an ignitor is important, but not the be-all/end-all when it comes to restartability. For example, the Apollo SPS was rated for essentially infinite restarts (although a set total burn time) because it was a pressure-fed hypergolic engine with ablative cooling: so long as there was still propellant to be fed to it, and the combustion chamber and nozzle hadn't ablated away too much, you could just open the vales and light it up (ullage willing). The Agena engine, however, was pump-fed, and thus needed to spin up its turbopumps before it could light its gas generator (which was there to power the turbopumps). A bit of a chicken-and-egg situation, but it could be gotten around by judicious use of stored electricity (IIRC) to spin up the turbopumps in the absense of the generator. That said, even with enough juice, after about 18 starts (well past the rated 15? Or was it 15 and 12?) stuff was getting too melty/corroded/whatever to work.

The advantage of hypergolics isn't so much that they have infinite restarts, it's that they are storable. LOX boils off. Means you can't store the missile, you have to fuel it up before launch--and that means you need a few hours' warning, not a few minutes. It's also an issue in space--that's why pretty much everyone uses hypergolics for on-orbit maneuvers and

Interesting stuff!

Is it accurate to say that the only way that early rockets would have multiple restarts would be be using monopropellant? (I do realize "early" is a bit vague here)

[NathanKell]

Ravenchant: Missed, sorry! Awesome, new contributions are wonderful!

As to removing engine shrouds, you can add a new node and tell the jettison modules to use it, but that's a bad method; we'd like to switch to doing what TweakableEverything does, making the shrouds toggleable ingame.

Oksbad: pressure-fed hypergolics at relatively low pressure aren't that much of a pain to deal with. IIRC the first restartable engine was the AJ10-104D on Ablestar (first launch April 1960), that should be available at TL2. Pressure-fed energetic (i.e. catalyzed) monopropellants like hydrazine would not be that much less of an engineering challenge than low-energy hypergolic bipropellants; the chamber temperature wouldn't be that much lower, etc. Really early on you're looking at cold-gas thrusters (as on Juno I/II), or the heated propane of the Able stage (modeled as HTP ingame).

[XkaOnslaught]

XkaOnslaught: I suggest using the M55 part that RO provides. It has a thrust curve, unlike the proc solid. Real solids don't generally maintain the same thrust throughout their burntime; thrust generally tails off. That will proportionally lower your TWR later in flight.

Friedrich Nietzsche: that's weird! I'd suggest posting about it on the TestFlight thread so Agathorn will be sure to see it. Regarding burn time--wait, it looks like you have only two LR-87s (i.e. one part) there? The Titan IIILs had four of them (two LR-87 parts)... IIIL2 link.

Regarding burnout Gs: you definitely ignore them if flying uncrewed. I'd suggest looking at the last few pages of the Real Fuels thread for a discussion of this issue. However, if you're hitting 15Gs at burnout, just how tiny an upper stage are you using? (I assume that's first-stage burnout). Or is it at booster burnout?

Actually i did try using the M55 before i made my own part, it's just that the M55 gimbal doesnt seem to be working :/ i made sure it wasnt the avionics screwing with me, but even with the 1m guidance ring it still doesnt want to turn :/

[Lilienthal]

XkaOnslaught: I suggest using the M55 part that RO provides. It has a thrust curve, unlike the proc solid. Real solids don't generally maintain the same thrust throughout their burntime; thrust generally tails off. That will proportionally lower your TWR later in flight.

Hi Nathan, wouldn't it be a good idea to have a generic thrust curve for the procedural solids as well? Maybe use the one for the M55?

[XkaOnslaught]

the Proc solids do have a thrust curve, but its based on its specific impulse, and it increases (which is incorrect for the early solids anyway).

based on that point, maybe a seperate proc solid part with a thrust curve that tails off at the end might be a good interim solution?

[FennexFox]

What should I do to make a NFT vasmir engine burn LiquidHydrogen, not Hydrogen?

I opened the CFG and it seems without problem, but my ship has zero delta-v.

[Kitspace]

Nathan

You say again that the burnout acceleration can be ignored if flying with unmanned payloads.

However there was this link on the previous page.

http://www.braeunig.us/space/specs/titan.htm

The article among others describes one of the late commercial Titan versions and mentions that the safe payload rating is six gees.

So each rocket stage is basically expected to stay below that number at all times.

How can that be this way?

Thank you!

[Kitspace]

Also can anyone help me solve a confusion?

How many engines is an LR-87?

Some think of it as two engines and some as one engine with two chambers in it.

How many combustion chambers how many engines and how many game parts did those late Titans have? They are described here like having four chambers on the first stage which contradicts to their visual appearance as well as the data around including the same link again.

http://www.braeunig.us/space/specs/titan.htm

All the sources state that they had the same first stage engines as the original size versions.

Edited April 12, 2015 by Kitspace

[StoryMusgrave]

@kitspace: That statement is very ambiguous. First look at the section it's in: Payload Fairing/Carrier. So what exactly is it talking about??? Maybe just the faring? Which IS separated before it sees 6G, while the payload itself will see much more. As it's been stated before, stop worrying about it. Unless you can find an original source that is more definitive of exactly what that particular passage is talking about.

As for the LR-87. It IS two engines. They just always work in a pair, which was called the LR-87. Each engine had it's own pump and chamber. No idea where you see 4 chambers at on that page. The LR-87 is a rare breed that saw (with mods) RP-1/LOX, Aerozine/NTO, and LOX/LH2. Still just the LR-87 but different model numbers like -3, -5, -7, -11, etc. As they progressed they were up rated in power.

[Kitspace]

That passage says the payload design requirement. I think it means the acceleration that the payload should be able to withstand safely. That section seems to be about the payloads too. And also it mentions the burnout peak force for each stage.

Nathan talks about the engines a few posts above.

Friedrich Nietzsche: Regarding burn time--wait, it looks like you have only two LR-87s (i.e. one part) there? The Titan IIILs had four of them (two LR-87 parts)... IIIL2 link.

[StoryMusgrave]

Yeah 3 words. With no real explicit context. On 'some internet page'. With no citations. Find actual original data/specifications and that's a horse of a different color. Explorer no doubt experienced pushing 40G. Gemini 7G. Solid structures are generally fine. Now perhaps the last time I said it didn't make it through. You don't launch a cube sat with a Delta IV Heavy. Use a launcher appropriate to the task. Also if a payload is so light, dV is going to be so high that an early shutdown is inevitable for most orbits.

American orbital launch vehicle. Variant of Titan with 15 foot Large Diameter Core, 2 x 7 segment strap-ons. Man-rated, optimized for delivery of heavy payloads into LEO. Never developed.

Now if you want to make a 3L2, then use two LR-87 parts, which is 4 engines. Being it was never developed though. YMMV.

Edited April 13, 2015 by StoryMusgrave

[JT2227]

Don't want to be too big of a fuss but does anyone know where these errors come up from? Frequent crashes from returning to the SPH,

InvalidOperationException: Collection was modified; enumeration operation may not execute.

at System.Collections.Generic.List`1+Enumerator[unityEngine.Collider].VerifyState () [0x00000] in <filename unknown>:0

at System.Collections.Generic.List`1+Enumerator[unityEngine.Collider].MoveNext () [0x00000] in <filename unknown>:0

at Part.OnDestroy () [0x00000] in <filename unknown>:0

(Filename: Line: -1)

[Phylan]

Does anyone know of a lighter-weight mod than Pingopete's RVE that gives Earth a bit of cloud cover? I love what he's done, but the in-atmosphere stuff from RVE is just too much and slows the ascent down to a crawl. I don't really need mega realism, just maybe some clouds to look at when in orbit.

[Hattivat]

Does anyone know of a lighter-weight mod than Pingopete's RVE that gives Earth a bit of cloud cover? I love what he's done, but the in-atmosphere stuff from RVE is just too much and slows the ascent down to a crawl. I don't really need mega realism, just maybe some clouds to look at when in orbit.

Just use the EVE overhaul, that's what I do. It should work out-of-the-box, no configuration necessary.

[Phylan]

Just use the EVE overhaul, that's what I do. It should work out-of-the-box, no configuration necessary.

oh, duh, I'll give that a shot, thank you. Not sure why I didn't think of that.

[ThorBeorn]

I decided to play without RF a bit and it struck me how used I have gotten to make tweaks using some of its features. Especially ModuleEngineConfigs and also its thrustcurve. Being able to add several engines "within the same engine" is really practical, the same goes for thrustcurves. Would it be possible to release just that part as a plugin to be used with stock resources?

Edit: Sorry wrong thread, too many browser tabs open, too little sleep.

Edited April 13, 2015 by ThorBeorn

[NathanKell]

XkaOnslaught: I'll check, maybe the Ven Stock Revamp model has a different transform or something. EDIT: I see the issue, fixed in git.

Lilienthal: yes, it is! Ferram's been working on that.

JT2227: need far more context than that. All that's saying is that some part threw an error due to a collider issue. That certainly would not cause a crash. Please actually follow the steps in the support thread when you crash.

Edited April 13, 2015 by NathanKell

[sisyphean]

so recently encountered another bug,

after finally (on my 3rd attempt) getting the first module of my space station into orbit i find that the resized stock science lab reverted to stock size once the vessel is unloaded and reloaded, i have tested this with a fresh launch of just the station and the result is in the image bellow.

http://imgur.com/UdpeN8Q

im wondering if the issue i was having with engineer redux lying to me about how much delta v i had when trying to launch this thing was in some way related to this bug perhaps the game cant work out which version to use maybe?

anyway if someone has a fix please let me know thanks in advance guys

[Rabada]

so recently encountered another bug,

after finally (on my 3rd attempt) getting the first module of my space station into orbit i find that the resized stock science lab reverted to stock size once the vessel is unloaded and reloaded, i have tested this with a fresh launch of just the station and the result is in the image bellow.

im wondering if the issue i was having with engineer redux lying to me about how much delta v i had when trying to launch this thing was in some way related to this bug perhaps the game cant work out which version to use maybe?

anyway if someone has a fix please let me know thanks in advance guys

I have had the same issue with the science lab re-sizing. I don't think that it has anything to do with Engineer. I've seen similiar bugs with re-sizing parts and I'm guessing that the problem is either in the RO .cfgs that edit the part (unlikely, the code looks fine to me), or the problem is in module manager itself (unlikely), or that the problem is a stock KSP, which seems the most likely to me. The Lab is already pretty buggy in stock KSP.

In place of the stock science lab, I used the science lab part from the Taurus Crew Capsule Mod. It's not quite the right size, but it looks a lot better than the stock science lab in my station. Here are two pics, its inbetween the hitchiker modules.

Edit: The issue for me could also be Ven's Stock Revamp.

Edited April 14, 2015 by Rabada