parts [1.12.x] Sounding Rockets! Start small. Dream big!

[insidery]

Hi i got a question, maybe bug report. for some reason ur warpdrive breakes science modules of sounding rockets, when wd is installed i have no menu for science, as soon as i nuker wd folder it works... took some time to figure it out so im sure its not other mods, i did tests on fresh install with ur mods only

[RoverDude]

Crowd sourced science apparently breaks stuff, and not just mine. I would not recommend loading it till they sort their issues out.

[ultrasquid]

  Frostiken said:

Am I supposed to be unable to steer them? Not using RemoteTech so that's not the issue.

Also these are lots of fun. I built a rocket that has all four science modules on it and use the little 'adapter' piece as a landing booster to bring the whole thing down intact.

You can try making a sort of bipod using the included stick to aim your sounding rockets if you want them to go somewhere other than straight up.

[Black-Talon]

I too have been loving Sounding Rockets! Or at least the concept of having the option of unmanned test flights for the early career!

Unfortunately, as we all already know, FAR is also wonderful and tends to really mess with the early game quite a bit. But with that said, I became interested enough to investigate what would be realistic performance within FAR for the Sounding Rockets.

One thing I did first was read a lot of wikipedia about Sounding Rockets and early rocket tests. It turns out, that for a test rocket to reach high altitudes isn't/wasn't all that unrealistic. It makes sense (and RoverDude has been telling us this in several posts) that having small unmanned rockets, with little care about their potential fiery doom, leaves a lot of room for high altitude sub-orbital test flights. ESPECIALLY multi-stage sounding rockets. In our real rocket history, test flights of Sounding Rockets reached apoapsis altitudes of over 200 km fairly early. If you consider the V2 as one of the earliest real rockets (which it was), note that in a vertical launch, it could reach a maximum altitude of 206 KM. Sounding Rocket performance over the next 10 years followed suit and some tests far exceeded this altitude. This history of rocket flights might be interesting to you, I know it was an enjoyable learning moment for me! https://en.wikipedia.org/wiki/Timeline_of_spaceflight

I was also worried that in career the early missions speak of altitude records. And It seemed a bit cheaty if these tiny rockets would immediately set a record on the first flight that invalidated many future contracts for altitude record setting. But as noted already in this thread, those contracts require a manned flight. Perfect!

Now FAR is known to eliminate the atmospheric soup while also rewarding aerodynamic design, which when combined makes it much easier to launch a rocket through the atmosphere. Mods such as Ferram's KIDS (KerbalIspDifficultyScaler) can counter this but it may not be for everyone. What about other concerns such as parachutes not getting a FAR drag model? And the drag created by the fins requiring a wing config in FAR to be modeled with the correct drag? Do those things matter to users of Sounding Rockets who want to use FAR? I compiled to following data from tests to find out:

https://docs.google.com/spreadsheets/d/1K9UVrXre7bIuG8vGBbowGKdB5ZK6XZxiga1wa1N4vmM/edit?usp=sharing (not yet complete)

Looking at the data, I'm going to go ahead and propose that either Ferram misspoke or there was a miscommunication...

  RoverDude said:

Yeah chatted with Ferram, and the only net change was a slight mass boost and ISP decrease on the smallest of the three rockets. The rest are inline and are behaving correctly.

  RoverDude said:

I had Ferram do a sanity check on the numbers and we agreed on the balance (minus one tweak which I did). So less a case of them being OP and more that stock Aero setting incorrect expectations.

The short of it can be summed up with this series of tests:

(Stock) Launching East at 40 deg off horizon - basic Sounding Rocket - Peak Altitude: 1,425 m - Speed at Impact: 83.6 m/s

( FAR ) Launching East at 40 deg off horizon - basic Sounding Rocket - Peak Altitude: 12,770 m - Speed at Impact: 1,363.8 m/s

(Identical booster/setup to test above)

(Stock) Launching East at 40 deg off horizon - stock fins & probe - Peak Altitude: 972 m - Speed at Impact: 94.7 m/s

( FAR ) Launching East at 40 deg off horizon - stock fins & probe - Peak Altitude: 1,306 m - Speed at Impact: 40.4 m/s

So we can conclude that FAR doesn't HAVE to drive performance into the OP spectrum... WHY does it do so for Sounding Rockets? I think the CommandPod Parachute is the PRIMARY factor but perhaps the fins not having FAR Aero on them also factors in. I made some FAR configs to fix the fins and (happy to share but they aren't complete - I'm not smart enough) and tested again:

(Fixes) Launching East at 40 deg off horizon - basic Sounding Rocket - Peak Altitude: 5,546 m - Speed at Impact: 136.5 m/s

Not bad! ...but I have more questions than answers it seems. I'm getting some NullRefExceptions in the logs all the sudden (when reverting to launch). I actually am shocked that the Stayputnik slows to 40.4 m/s in a free fall descent causing me to question what drag is being applied. And I'm using Ferram's FARBasicDragModel Module to apply drag to the Nosecone but am at a total loss for what the values in that module actually mean (I copied some values Ferram is applying to a FASA part). So...more testing to do and I'd welcome some help figuring out the right values to put on parts. I do feel pretty good about the fins...I just don't know how it actually impacts things. [WIP]FAR ModuleManager Configs: https://www.dropbox.com/s/6kgtqncsyxuui3a/FAR%20ModuleManager%20Configs.zip?dl=0

Eager to hear your thoughts!

Unrelated...would you consider it a bug that the booster does not jettison itself from the payload if the booster is the root part? I had to set the nosecone as the root part to jettison. It helped me test the drag while falling back to Kerbin by having all the parts still together but I'm not sure that's intended behavior so I thought I would share.

-Talon

[RoverDude]

Thanks for the data

From my side, probably the only change I am considering at the moment is reviewing the TWR and doing some slight tweaking in that direction to make the SR's more in line with a stock starting SRB. RE the bug - because of how decoupling works, you should not have a booster as a root part - it will only decouple from it's parent.

[djnattyd]

Rover not sure if this has already been mentioned but the stock altitude record contracts aren't completable using a sounding rocket, it seems as though the contract required a manned pod.

I can't even find where those contracts are stored in the install so I don't know if it's changeable.

[ev0]

  ev0 said:

Just started using the new parts and noticed that the Aeronomy Sensor Array, Meteorological Survey Array, and Materials Study Mini-lab are are all three called "Meteorological Survey Package" in the parts menu. The Engineering and Instrument Test Bay is rightly called "Engineering Survey Package".

Hi Roverdude, did you happen to see this post of mine several pages back?

[RoverDude]

  PDelta41 said:

I got a contract to put the meteorological package on a satellite. Is there any way to keep that from happening? Also, I've been working on a module manager cfg to make these less OP with FAR installed. Do you have target max altitudes for the 1, 2, and 3 stage versions?

No set target altitudes, best bet would be to compare them to stock. Though I am doing a TWR review just in case that needs more tweaking.

  djnattyd said:

Rover not sure if this has already been mentioned but the stock altitude record contracts aren't completable using a sounding rocket, it seems as though the contract required a manned pod.

I can't even find where those contracts are stored in the install so I don't know if it's changeable.

Those records require a manned capsule. So they should not be triggered with sounding rockets. That being said, they are awesome for early science (which is their intent).

[Black-Talon]

  PDelta41 said:

I've been working on a module manager cfg to make these less OP with FAR installed. Do you have target max altitudes for the 1, 2, and 3 stage versions?

@PDelta - Can we team up on this? See my post with data regarding performance of at least one of the stock boosters. I'd be happy to provide more AND provide some testing. Note that the biggest problem that would make this better inline with stock is if the Command/Parachute Nosecone actually had some drag. Currently it has zero drag and this makes it fly infinitely faster when accelerated by gravity.

  RoverDude said:

Thanks for the data

From my side, probably the only change I am considering at the moment is reviewing the TWR and doing some slight tweaking in that direction to make the SR's more in line with a stock starting SRB. RE the bug - because of how decoupling works, you should not have a booster as a root part - it will only decouple from it's parent.

@RoverDude - I'm always a fan of tweaking TWR. :-) But am I hearing you correctly that you wouldn't be interested in putting the FAR Modules into the configs of your download? Or alternatively providing ModuleManager configs (that would only be applied IF/WHEN FAR/NEAR was installed) as part of the Sounding Rockets package? I would really like to urge you to consider differently; currently it is accurate to say that Sounding Rockets does not work well/correctly with FAR specifically because the Nosecone part has Zero Drag applied to it in FAR. This is fixable with configs that I, and I presume others, would be happy to create and test. These configs (with the ModuleManager option) wouldn't even be in the stock configs or otherwise conflicting with the stock game (in either option). It seems a lot of people in the thread would desire this, and the primary cause for concern is a broken physics issue (no drag on the return capsule), which is fixable as I demonstrated. I'll leave it at that, thanks for hearing out my two-cents. In the meantime do you have any concern with me posting links to ModuleManager configs that allow Sounding Rockets to work with FAR without this zero drag issue?

-Talon

Edited December 23, 2014 by Black-Talon
typos and stuff

[RoverDude]

Oh not at all - if someone were to provide me FAR configs that they tested, I would happily include them!

[PDelta41]

@Black-Talon, I'd be happy to work with you. I hadn't actually looked at the drag coefficients at all, I'm not sure how to to make FAR recognize that, actually. I've just been playing with thrust and payload, with less than wonderful results. Also, I've been working in career mode, so I'm past sounding rockets with that. On the other hand, I'll gladly start a new save if you want to collaborate.

Edit: Just checked out your data, I'll start playing with configurations tomorrow.

Edited December 23, 2014 by PDelta41
Data

[Black-Talon]

  PDelta41 said:

@Black-Talon, I'd be happy to work with you. I hadn't actually looked at the drag coefficients at all, I'm not sure how to to make FAR recognize that, actually. I've just been playing with thrust and payload, with less than wonderful results. Also, I've been working in career mode, so I'm past sounding rockets with that. On the other hand, I'll gladly start a new save if you want to collaborate.

Edit: Just checked out your data, I'll start playing with configurations tomorrow.

Seeing your edit, yeah, take a look at that data and let me know if it makes any sense. I've saved each Test (Test01, Test02, Test03) as a separate .craft so you can tweak settings/configs and load the craft(s), fire, write down the results. Nice and controlled. Have at those here if you'd like (perhaps more tests to come later): https://www.dropbox.com/s/w1yp64bxhv9iapk/SoundingRocketsFarCraftTests.zip?dl=0

Also you saw the link for the ModuleManager.cfg I already made? Give that a try it makes a pretty big difference already.

FWIW, I follow this https://github.com/ferram4/Ferram-Aerospace-Research/wiki/Deriving-FAR-values-for-a-wing-using-Blender-2.7 to add the FAR values to the fins. This leaves me really confident that those are correct BUT it would be awesome for someone to look over the results and see if I messed up anything.

Despite feeling good about the fins, I don't think they're the major problem. That Nosecone is the issue. Since it has a parachute FAR eliminates all the drag except when it's deployed (in fact, even when deployed it may just be using the stock drag model). You can see what I did in the config (which actually has a typo for the "BEFOR" statement - should correct that first!) and perhaps more importantly I asked if Ferram could perhaps explain those values a bit more and how to determine what they should be for a part like this - post here: http://forum.kerbalspaceprogram.com/threads/20451-0-90-Ferram-Aerospace-Research-v0-14-5-1-12-19-14?p=1623648&viewfull=1#post1623648

So once that's all done right I'd like to re-compare stock performance of tier 0 sounding rockets (and stock parts) to tier 0 with FAR installed. We could surely be concerned about thrust, mass, Isp if we want...but from my perspective we don't know if it's really that big of a deal until we get the drag working correctly. In general I'd rather not change the thrust/mass just for FAR...because once we do that we might as well adjust the thrust for all the other engines in FAR as well and that's just out of scope here. :-)

Thanks for offering the help - feel free to PM me or leave questions here - I'm anxious to know what you make of it all!

[Black-Talon]

Grrr - Christmas is ruined because I just now realized/found out that in the "Flight Results" window (comes up after crashing a flight or if you press F3 while in flight) that lists "Highest Speed Achieved" tends to max out at 750 m/s.

  Claw said:

"Highest Speed Achieved" is literally the highest "Surface" navball speed, in any direction that you achieved. It will be the highest readout you see in the "Surface" navball readout. However, it seems to max out at 750 m/s for reasons I don't understand.

-Claw

Frustrating since I didn't catch it while testing - the results that are over 750 m/s are from cases where I couldn't/didn't use the Flight Results window, the ones that list values around 750 m/s are probably wrong.

[Artophwar]

I am definitely interested in FAR cfgs.

[Black-Talon]

To cut through some of my windy posts - These are the FAR Configs I am currently testing - you can test them too!

[WIP]FAR ModuleManager Configs for Sounding Rockets v0.0.1.0: FAR ModuleManager Configs.zip

I think they can be improved, specifically the Nosecone drag. I don't understand those parameters for FARDragModel, I just copied some.

TODOs -

1. Nosecone performance is realistic & balanced with other command pods - In Testing
   
2. Ferram suggests: "Load [the Nosecone] up in-game without the parachute module on, then dump the drag configs." - Did this and updated download
   
3. They should not change anything unless FAR is installed - Not tested
   
4. I would like it to work with NEAR - Not attempted or tested
   
5. I'm confident in the fin changes - double check my measurements for FAR? make sure I didn't copy and paste or math error?
   

Update: New download with better Nosecone drag config - I like the performance well enough but haven't been able to test much since with this change something gets really upset and upon Reverting to Launch I get a steam of NullRef Exceptions and FAR drag seems to be mucked up at that point. I haven't been able to pinpoint it yet. It so far *seems* specific to the Nosecone part. Which...I cannot get the FAR Menu to open in-flight when that part is equipped so that seems likely. What I don't understand is why that would be the case. Documented issue here: http://forum.kerbalspaceprogram.com/threads/20451-0-90-Ferram-Aerospace-Research-v0-14-5-1-12-19-14?p=1627099&viewfull=1#post1627099

Edited December 24, 2014 by Black-Talon
Update download

[RoverDude]

0.1.1 is up!

USI Tools update

Increased mass of experiments and fixed titles

Made small rocket radially attachable

Increased parachute drag

[Exolinguist]

To Whom It May Concern:

I was wondering if the devs of this mod would be kind enough to consider adapting the science payloads so that they could be used as parts for constructing meteorological satellites and such. I would great appreciate it if you could give some thought to that.

Thank you.

[RoverDude]

By devs that would be me

And I'm not sure what you are asking for specifically.

Oh... and I am testing a Christmas surprise for you folks...

[Exolinguist]

Hi.

Thanks for the quick response! What I would like to see is if the meteorological and aeronomical rocket payload parts could be changed into parts that perform the same science collecting function (but multiple times), but designed to be placed on a probe so we could make working meteorological satellites.

If that sounds intriguing to you, you would have an enthusiastic mod customer in me!

[TinyPirate]

Hi RoverDude! Been enjoying the mod. I've profiled it in a little mod series I'm doing. Hope you enjoy my terrible failures.

Edited December 26, 2014 by TinyPirate

[biohazard15]

A quick fix for any of you who wish to use RemoteTech and Sounding Rockets simultaneously without having to add antenna and battery to your rocket.

@PART[SR_NoseCone]:FOR[RemoteTech]
{
	%MODULE[ModuleSPU] {
	}

	%MODULE[ModuleRTAntennaPassive]	{
		%TechRequired = start
		%OmniRange = 500000

		}
	}
}

It will add a passive antenna to SR nosecone. Range up to 500 km. Cannot be used to transmit data.

[hyperionxl]

  biohazard15 said:

A quick fix for any of you who wish to use RemoteTech and Sounding Rockets simultaneously without having to add antenna and battery to your rocket.

@PART[SR_NoseCone]:FOR[RemoteTech]
{
	%MODULE[ModuleSPU] {
	}

	%MODULE[ModuleRTAntennaPassive]	{
		%TechRequired = start
		%OmniRange = 500000

		}
	}
}

It will add a passive antenna to SR nosecone. Range up to 500 km. Cannot be used to transmit data.

Where do we put that code?

[biohazard15]

  hyperionxl said:

Where do we put that code?

Create a new text document with Notepad, put it there, save file under some name you like and change extension from .txt to .cfg. Then put this .cfg into GameData. You'll need Module Manager, obviously (comes with RT).

Do not put it into RT folder, and do not put this code into RT configs. Using dedicated file will ensure that you won't delete it by accident when updating RT.

[RoverDude]

FYI - added an inline parachute for you folks that and the weather balloon/blimp will be in the next official release.

[ModZero]

Hi there, I come bearing bugs (possibly not in this mod, though - also sorry if this is known, I didn't spot it in a search).

If there's Kerbal Joint Reinforcement installed, first stage of a two-stage SR doesn't drop if there are fins attached to the first stage, but it works correctly on a rocket without these fins. To make things even more confusing, this (sounding rocket with fins, but using small boosters for both stages) works properly.

Sorry if it's not your bug - it seems to be an interaction with KJR. Here's a log of a single launch of the broken rocket.

EDIT: also, I remember it happening before I upgraded KJR, but I didn't do any isolated tests back then.