Project Multistage2015 - Development Thread

[jacquesmomo]

I updated on OH both 2010P1 and 2016 version

Thanks ! I'll test both of them this evening (or night !) :lol:

 

[gattispilot]

I have run into an issue.
I get a CTD when I press J focused on the MS2015 vessel

This is the log:

000000.000: Module Multistage2015.dll .... [Build 170626, API 160828]
000000.000: Multistage Version: 170506
000000.000: Load State Started
000000.000: TITAN3M: Guidance File present: Config\Multistage2015\Guidance\SLS_EM1_Orion_GNC.txt
000000.000: TITAN3M: Orbit Call Found! Targets: Apogee:200000.0 Perigee:200000.0 Inclination:-29.6 Mode:1.0 GT initial Pitch: 76.5 Abside:200000.0
000000.000: TITAN3M: Config File: C:\Orbiter2016\Config\Multistage2015\TITAN3MOL.ini
000000.000: TITAN3M: Number of Interstages in the ini file: 1
000000.000: TITAN3M: Number of stages in the ini file: 2
000000.000: TITAN3M: Number of boosters group in the ini file: 2
000000.000: TITAN3M: Number of Payloads in the ini file: 2
000000.000: TITAN3M: Texture n.1 Loaded Exhaust_atsme
000000.000: TITAN3M: Texture n.2 Loaded SLS_2016\SSME_Exhaust
000000.000: TITAN3M: Stage n. 2 Tank Added: 26535.000 kg
000000.000: TITAN3M: Stage n.2 Engine Exhaust Stream Added: sa to engine n.1
000000.000: TITAN3M: Stage n. 2 Engines Exhaust Added--> number of engines: 1 , diameter: 1.200, position x: 0.000 y: 0.000 z: -5.400
000000.000: TITAN3M: Stage n.2 Mesh Preloaded: ProjectGemini/Titan22
000000.000: TITAN3M: Stage n.2 Mesh Added Mesh: ProjectGemini/Titan22 @ x:0.000 y:0.000 z:0.000
000000.000: Load State Terminated
000000.000: Module MS_Camera.dll ......... [Build 170626, API 160828]
000000.000: MS_Camera: Target Vessel Loaded->TITAN3M
000000.000: Module Spacecraft4.dll ....... [Build 151223, API 100830]
--------------------------- WARNING: --------------------------
>>> Texture not found: RCS-Gemini.dds
Skipping.
>>> [TextureManager::AcquireTexture | .\Texture.cpp | 1040]
---------------------------------------------------------------
000000.000: Finished initialising status
000000.000: Finished initialising camera
000000.000: Finished setting up render state
000000.000: Post Creation Started
000000.000: RESET PEG
000000.000: TITAN3M: Planet Reference Pressure = 101325.0 Pa  Atmosphere Altitude Limit:2500.0 km
000000.000: Post Creation Terminated
000000.000: Finished initialising panels

SCn:

BEGIN_SHIPS
TITAN3M:Multistage2015
  STATUS Orbiting Earth
  RPOS 5535450.928 3429695.208 -792361.265
  RVEL 2815.7932 -4079.3446 4822.2559
  AROT -32.331 -41.884 67.065
  VROT 0.1210 0.0019 0.0038
  AFCMODE 7
  NAVFREQ 0 0 0 0
  XPDR 0
  CONFIG_FILE Config\Multistage2015\TITAN3MOL.ini
  GUIDANCE_FILE Config\Multistage2015\Guidance\SLS_EM1_Orion_GNC.txt
  CONFIGURATION 1
  CURRENT_BOOSTER 3
  CURRENT_STAGE 2
  CURRENT_INTERSTAGE 2
  CURRENT_PAYLOAD 1
  FAIRING 0
  MET 425.237
  GNC_RUN 1
  GROWING_PARTICLES 
  STAGE_IGNITION_TIME 158.103939
  STAGE_STATE 2
  TELEMETRY_FILE Config\Multistage2015\Telemetry\SLS_EM1_Orion_GNC.txt
  ALT_STEPS 200.0,350.0,1400.0,35000.0
  PEG_PITCH_LIMIT 35.000
  PEG_MC_INTERVAL 0.100
END
MS_Camera:MS_Camera
  STATUS Landed Earth
  POS -80.5242150 28.5170550
  HEADING 71.00
  ALT 0.000
  AROT -118.188 -4.508 171.657
  AFCMODE 7
  NAVFREQ 0 0
  TARGET TITAN3M
END
MOL:geminiMOL
  STATUS Orbiting Earth
  RPOS 5535459.310 3429690.209 -792353.367
  RVEL 2815.7932 -4079.3446 4822.2559
  AROT -32.331 -41.884 -22.935
  VROT 0.0019 -0.1210 0.0038
  ATTACHED 0:0,TITAN3M
  AFCMODE 7
  PRPLEVEL 0:1.000000
  IDS 0:468 100 1:468 100
  NAVFREQ 0 0
  XPDR 100
END
Gemini9:Spacecraft/Gemini9
  STATUS Orbiting Earth
  RPOS 5535466.654 3429685.829 -792346.447
  RVEL 2815.7932 -4079.3446 4822.2559
  AROT -32.331 -41.884 67.065
  VROT 0.1210 0.0019 0.0038
  ATTACHED 0:1,TITAN3M
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
  XPDR 220
  CONFIGURATION 1
  CURRENT_PAYLOAD 0
  SEQ 0 -2 0.000000
  SEQ 1 -2 0.000000
  SEQ 2 -2 0.000000
  SEQ 3 -2 0.000000
  SEQ 4 -2 0.000000
END
END_SHIPS

ini:

[MISC]
cog=8.000
GNC_Debug=0
Telemetry=0
Focus=1
Thrust_real_pos=0
Vertical_Angle=0.000

[TEXTURE_LIST]
TEX_1=Exhaust_atsme
TEX_2=SLS_2016\SSME_Exhaust

[BOOSTER_1]
N=1
MeshName=TITANBOOSTERLEFT
Height=32
Diameter=3
EmptyMass=51230
FuelMass=268010
Thrust=7116999
angle=3.142
off=(-3,0.00,9.5)
BurnTime=126
eng_1=(0.000,0.000,-15.000)
eng_diameter=1.5
ENG_PSTREAM1=exhaust
Speed=(-15.000,0.000,0.000)
Rot_speed=(0.000,0.400,0.000)
Eng_tex=
Eng_pstream2=contrail

[BOOSTER_2]
N=1
MeshName=TITANBOOSTERRIGHT
Diameter=3
EmptyMass=51230
FuelMass=268010
Thrust=7116999
angle=3.142
off=(3,0.000,9.5)
BurnTime=126
eng_1=(0.000,0.000,-15.000)
eng_diameter=1.5
ENG_PSTREAM1=exhaust
Speed=(15.000,0.000,0.000)
Rot_speed=(0.000,-0.400,0.000)
Eng_tex=
Eng_pstream2=contrail

[STAGE_1]
Height=21.3
Diameter=3
off=(0.000,0.000,4.700)
MeshName="ProjectGemini/Titan21"
EmptyMass=18000.0 
FuelMass=99000.0 
Thrust=1900000.0
BurnTime=156
eng_1=(0.7,0,-11.2)
eng_2=(-0.7,0,-11.2)
eng_diameter=0.8
PITCHTHRUST=14193633.100 
YAWTHRUST=14193633.100 
speed=(0.000,0.000,-2.000)
ENG_PSTREAM1=engdetail_2
battery=1.500
Reignitable=1
Eng_tex=SLS_2016\SSME_Exhaust
Eng_pstream2=engdetail
Eng_dir=(0.000,0.000,1.000)
Module=Stage
Rot_speed=(0.000,0.000,0.000)

[SEPARATION_12]
MESHNAME="ProjectGemini/Titan2i"
OFF=(0,0,12.5)
HEIGHT=3.2
DIAMETER=3
EMPTYMASS=10
SEPARATION_DELAY=4
SPEED=(0,0,-3)
ROT_SPEED(.1,-0.1,0)

[STAGE_2]
MESHNAME="ProjectGemini/Titan22"
OFF=(0,0,17.445)
HEIGHT=8
DIAMETER=3
EmptyMass=2404
FuelMass=26535
IGNITE_DELAY=3
Thrust=445000 		
BurnTime=202
YAWTHRUST=2500
PITCHTHRUST=2500
ROLLTHRUST=1200
eng_1=(0,0,-5.4)
eng_diameter=1.2
ENG_PSTREAM2=sa
SPEED=(0,0,0)
IGNITE_DELAY=3
ROT_SPEED=(0,0,0)
ENG_TEX=Exhaust2

[PAYLOAD_1]
MeshName=GeminiMol/mol
off=(0.000,0.000,30)
Rotation=(0.000,0.000,90.000)
Diameter=3.000
Height=17.000
MASS=14476
Module=GeminiMol
Name=MOL
SPEED=(0.000,0.000,2.000)
RENDER=1
Rotation=(0.000,0.000,0.000)
Rot_speed=(0.000,0.000,0.000)
Live=1

[PAYLOAD_2]
MeshName=ProjectGemini/Gem_Payload
Off=(0.000,0.000,41.000)
Height=6.500
Diameter=3.000
Mass=3500.000
Module=Spacecraft/Gemini9
Name=Gemini9
Render=1
Live=1
SPEED=(0.000,0.000,0.700)
Rotation=(0.000,0.000,0.000)
Rot_speed=(0.000,0.000,0.000)

 

[fred18]

I have run into an issue.
I get a CTD when I press J focused on the MS2015 vessel

This is the log:

It seems to me a SC4 issue, but I'm not sure. Can you try to use another payload just for test purpose with the very same scenario? just plug the carina into the ini file for payloads. If the CTD still occurs it can be related to MS2015, if not it's surely related to SC4

 

[gattispilot]

Thanks. So I did this:
scn

MOL:geminiMOL
  STATUS Orbiting Earth
  RPOS 5535459.310 3429690.209 -792353.367
  RVEL 2815.7932 -4079.3446 4822.2559
  AROT -32.331 -41.884 -22.935
  VROT 0.0019 -0.1210 0.0038
  ATTACHED 0:0,TITAN3M
  AFCMODE 7
  PRPLEVEL 0:1.000000
  IDS 0:468 100 1:468 100
  NAVFREQ 0 0
  XPDR 100
END
MOL1:geminiMOL
  STATUS Orbiting Earth
  RPOS 5535466.654 3429685.829 -792346.447
  RVEL 2815.7932 -4079.3446 4822.2559
  AROT -32.331 -41.884 67.065
  VROT 0.1210 0.0019 0.0038
  ATTACHED 0:1,TITAN3M
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0
  XPDR 220
END

ini

[PAYLOAD_1]
MeshName=GeminiMol/mol
off=(0.000,0.000,30)
Rotation=(0.000,0.000,90.000)
Diameter=3.000
Height=17.000
MASS=14476
Module=GeminiMol
Name=MOL
SPEED=(0.000,0.000,2.000)
RENDER=1
Rotation=(0.000,0.000,0.000)
Rot_speed=(0.000,0.000,0.000)
Live=1

[PAYLOAD_2]
MeshName=GeminiMol/mol
Off=(0.000,0.000,41.000)
Height=6.500
Diameter=3.000
Mass=3500.000
Module=GeminiMol
Name=MOL1
Render=1
Live=1
SPEED=(0.000,0.000,0.700)
Rotation=(0.000,0.000,0.000)
Rot_speed=(0.000,0.000,0.000)

this is the mol.cfg

; === Configuration file for MOL ===

Meshname = GeminiMOL/Mol
Mass = 11476
MaxFuel = 100  ; max fuel mass [kg]
Isp = 255       ; fuel specific impulse [m/s]
MaxAttitudeThrust = 1000
EnableFocus = TRUE
EnableXPDR = TRUE
XPDR = 100

BEGIN_DOCKLIST
0 0 10.25 0 0 1  0 1 0 468
0 .718 7.655 0 0 1  0 1 0 468
END_DOCKLIST

and log:
000000.000: Module Multistage2015.dll .... [Build 170626, API 160828]
000000.000: Multistage Version: 170506
000000.000: Load State Started
000000.000: TITAN3M: Guidance File present: Config\Multistage2015\Guidance\SLS_EM1_Orion_GNC.txt
000000.000: TITAN3M: Orbit Call Found! Targets: Apogee:200000.0 Perigee:200000.0 Inclination:-29.6 Mode:1.0 GT initial Pitch: 76.5 Abside:200000.0
000000.000: TITAN3M: Config File: C:\Orbiter2016\Config\Multistage2015\TITAN3MOL1.ini
000000.000: TITAN3M: Number of Interstages in the ini file: 1
000000.000: TITAN3M: Number of stages in the ini file: 2
000000.000: TITAN3M: Number of boosters group in the ini file: 2
000000.000: TITAN3M: Number of Payloads in the ini file: 2
000000.000: TITAN3M: Texture n.1 Loaded Exhaust_atsme
000000.000: TITAN3M: Texture n.2 Loaded SLS_2016\SSME_Exhaust
000000.000: TITAN3M: Stage n. 2 Tank Added: 26535.000 kg
000000.000: TITAN3M: Stage n.2 Engine Exhaust Stream Added: sa to engine n.1
000000.000: TITAN3M: Stage n. 2 Engines Exhaust Added--> number of engines: 1 , diameter: 1.200, position x: 0.000 y: 0.000 z: -5.400
000000.000: TITAN3M: Stage n.2 Mesh Preloaded: ProjectGemini/Titan22
000000.000: TITAN3M: Stage n.2 Mesh Added Mesh: ProjectGemini/Titan22 @ x:0.000 y:0.000 z:0.000
000000.000: Load State Terminated
000000.000: Module MS_Camera.dll ......... [Build 170626, API 160828]
000000.000: MS_Camera: Target Vessel Loaded->TITAN3M
000000.000: Finished initialising status
000000.000: Finished initialising camera
000000.000: Finished setting up render state
000000.000: Post Creation Started
000000.000: RESET PEG
000000.000: TITAN3M: Planet Reference Pressure = 101325.0 Pa Atmosphere Altitude Limit:2500.0 km
000000.000: Post Creation Terminated
000000.000: Finished initialising panels

 

[fred18]

And does it work? I don't understand

 

[gattispilot]

No ctd. I tried with out attachment manger and same result, CTD. Thanks

 

[fred18]

Try not to put them live and see if that works so i'll see where to check. And use a default module, like the carina one

 

[4throck]

Trying to do some Titan rockets in Multistage 2015 and get them as perfect as possible.
I have some questions!

- Ullage rockets are supposed to be "on" all the time ?

- How to best simulate gimballed / fixed engines ? Invisible ullage rockets placed next to the main engine ?

- How to limit gimball angle? I know I can define limits to pitch/roll/yaw rates...

- Is is possible to "pre-fire" the next stage, while attached? Titans did this, they ignited the second stage while attached, and that achieved separation.


I'd appreciate any help
These are small details but make a big difference regarding overall realism.

 

[fred18]

trying to answer:

- Ullage rockets are supposed to be "on" all the time ?

Of course not: Ullage_anticipation and Ullage_overlap are the parameters that sets the fire time of the ullages.
Anticipation sets the seconds at which ullage is fired BEFORE next stage engine fires
Overlap sets the seconds at which ullage is turned off AFTER next stage engine is fired (overlap because it's the same to say the seconds during which main engine and ullage are both on)

- How to best simulate gimballed / fixed engines ? Invisible ullage rockets placed next to the main engine ?

do you mean graphically?
I see it very difficult to do it with ms2015 as it is. I never implemented thrust vectoring because it would have required to animate also engine bells, leading to a massive sets of parameters for a general module as multistage... so you can try, but I honestly see it very difficult to do without coding it apart.

- How to limit gimball angle? I know I can define limits to pitch/roll/yaw rates...

the only way is not to use the guidance "orbit" program, but to manually set the guidance "old style". the orbit program uses default pyr rates. The option to customize them can actually be implemented in the future, noted in the todo list!

- Is is possible to "pre-fire" the next stage, while attached? Titans did this, they ignited the second stage while attached, and that achieved separation.

no. The way multistage works is that it is a unique vessel that "loses pieces" during the flight, so the next stage engine doesn't exist when this stage is firing. What you ask s is part of a multistage multimodule option that I have in mind since I started this project. I thought of making it using dockings but they don't have the same easy usage of attachments, and attachments do not bring physics to the game. If they do not bring physics then all the calculation shall be made "by hand" by the module, and that's the same of having a unique module... so that's why I still have not implemented a multimodule multistage...


Hope to have been helpful and clear

 

[4throck]

Thanks for the answers, they are helpful.


I'm using ullage as RCS jets (*).
Perhaps they are only meant to be used for stage separation ?
On that case I can use them to simulate the "pre-fire", problem solved!


No need to animate gimballing.
I'm only looking for the best way to simulate the different situations.
We have Pitchthrust, Yawthrust and Rollthrust but those are for RCS.

For rockets with no RCS, perhaps you should change Eng_dir=(xx,yy,zz) to simulate to engine angle/thrust vectoring ? Perhaps Eng_max_ang=(zzº)
May be complicated with multiple engines, but should provide a good simulation of the effect...


I like the autopilot! If you have the rocket configured with the right values, the autopilot gives you a realistic flight. That's why it's important to have realistic attitude control.


(*) by RCS I mean any system of attitude control using some kind of jets. Sometimes they were named differently.

 

[fred18]

The multistage module has a built in attitude system, which is just made by invisible RCS thrusters. The default value for attitude thrust is a % of main thrust (can't remember how much now) in the idea that it's the thrust vectoring orienting the rocket.

I don't completely understand what you mean by using ullage as RCS.

I think that we have to divide the package in 2 parts:

- physical part
- graphical/eye candy part

for the physical part the difference of implementing an invisible RCS system instead of thrust vectoring is minimum in terms of orbiter simulation. Thrust Vectoring generates also a drift and a small amount of thrust reduction which is not there with invisible RCS, but to give you an idea about thrust reduction IIRC for the SLS a maximum gimbal angle for SSMEs of 6° was considered, and the cosine of 6° is 0.9945, which means a thrust reduction of 0.55% when the engine is fully turned, so basically always 0.
Drift could be more significant, but thrust vectoring usually happens in the first part of flight, where atmosphere still plays a role and with drag it basically nulls the drift. So in physical terms, at least as far as i'm concerned, in the orbiter simulation an invisible RCS or a thrust vectoring system produce basically the same effect. That's why MS2015 uses an invisible RCS system for all rockets.

for the graphical part that's totally another story, since it could be very nice to see exhausts and engine bells turning but I noticed that in order to have a clearly visible effect the gimbaling angle should have been multiplied because variations are usually minimum (are you usually able to notice engine gimbaling when you watch a video of a rocket launch?) and doing this was meaning complicate the things a lot in order to have a not realistic effect, then i didn't see the point.

So IMHO if you are looking to best simulate thrust vectoring physics you can try to code another rocket module, but I'm pretty sure that you'll find out that attitude control will have an almost identical behaviour than an invisible RCS system.

going to another topic: using ullage to simulate prefire. I don't think it will work: until this stage is detached, all the engines of the next stage don't exhist yet. I think the best way to do it is to make a ghost-booster (word game is unintentional..): you set up a booster with the exhaust specifications identical to the second stage engine, you assign an empty mesh to it, you put it in the same location of second stage engine and you calibrate its burn_delay in order to match your needings. Curiously if you set also the thrust and calculate fuel properly, this solution will produce a result which is both physically and graphically correct.

the Eng_dir param is for fixed rotation of engines. That was built for the Space Shuttle or similar vehicles (my fault not to have included an example of it, it would have been very interesting to show) which have engine thrust not towards their Z axis. I have to say that the launch of the Shuttle was quite nice with that effect, I'll have to add its example to the package.

Hope this helps!
Cheers
Fred

 

[4throck]

Thanks for the detailed info.

Reading your description of the Eng_dir param you already have implemented fixed trust vectoring!
I agree that there's little difference to invisible RCS for all practical purposes. (On some launches you can see the exhaust angle change a bit for corrections, but it a small amount.)

The location of those invisible RCS may make a difference.
Do you place them around the main engine location, or at the rocket stage center ?

 

[fred18]

Thanks for the detailed info.

Reading your description of the Eng_dir param you already have implemented fixed trust vectoring!
I agree that there's little difference to invisible RCS for all practical purposes. (On some launches you can see the exhaust angle change a bit for corrections, but it a small amount.)

The location of those invisible RCS may make a difference.
Do you place them around the main engine location, or at the rocket stage center ?

1 meter from the rocket center of mass, that's why they don't produce the drift, basically you can scale the distance by setting the pitch/roll/yawthrust. It's the very same of what Vinka did with Spacecraft

 

[DaveS]

1 meter from the rocket center of mass, that's why they don't produce the drift, basically you can scale the distance by setting the pitch/roll/yawthrust. It's the very same of what Vinka did with Spacecraft

Well, that's a bit of cheat actually. All thrusters produce a bit of waste thrust unless they're specifically located at ideal points. I know of no spacecraft or rocket stage that ever had it that way.

Here's two charts that show the RCS for the shuttle and as you can tell by the Thrust Components sections (X is FWD/aft, Y is left/right and Z is up/down), most jets most definitely waste thrust.

https://www.dropbox.com/s/rklsqpjltvm354e/RCS_locations.jpg?dl=0
https://www.dropbox.com/s/60rqwh1lgjhvw1d/RCS_locations2.jpg?dl=0

 

[fred18]

Well, that's a bit of cheat actually.

I'd say yes, but it's impossible to avoid it for a general module such as Multistage. It needs to grant proper attitude control to any possible rocket the user may design, so it basically needs to turn the rocket properly when used. The invisible RCS doesn't even use fuel. It applies the very same method Vinka used for multistage.

Of course for detailed realism the best option is always to code a specific vessel in every detail, but as you know Multistage is a general module, and for this purpose I think it does its job quite ok.

thanks for the charts!

 

[4throck]

I agree that for a generic module must be simple.

My questions were all related to getting realistic performance from the autopilot.
I'm sure that a way of setting the placement (the center) of the invisible RCS would add to realism.
But I do agree that it must be simple and work as a general solution.


All this is positive criticism, Multistage is a great achievement and I'm a fan!

 

[boogabooga]

Hi there,

@boogabooga and the others: would you please check in orbiter2010 if the camera now works properly with this modules? thanks!

Fred

I only tested the default scenario with SLS. It seemed that the camera works better in Orbiter 2010 now. At least for the module you provided there in the thread. I haven't tried what is "official" on O-H now.

But, I still strongly disagreed with how the "G force" is being calculated. I strongly recommend that you implement the algorithm that both asbjos and Face provided. Or, use the "thrust/drag only" algorithm that you had going for the Orbiter 2016 version.

 

[fred18]

But, I still strongly disagreed with how the "G force" is being calculated. I strongly recommend that you implement the algorithm that both asbjos and Face provided. Or, use the "thrust/drag only" algorithm that you had going for the Orbiter 2016 version.

It should be simply thrust / mass. I hope that in the OH is calculated in this way for both o2010 and o2016, if it's not it means i forgot to update one of the versions, i'll check

 

[4throck]

Fred, another question

I tried to use venting to simulate ice around the rocket.
Just changing the direction has little effect, the particles end up on a horizontal flow (wind?).
I can make them go down by adjusting speed, but that ruins the effect a bit. They just move too fast.

Any suggestions about ideal settings for this? I'd like the particles to go slowly down along the rocket stage

 

[jacquesmomo]

Fred, another question
Just changing the direction has little effect, the particles end up on a horizontal flow (wind?).

this is difficult to adjust :
If you disable the Wind, the result is not the same...
And even with same values with and/or without D3D9, the result is also different....

It will be hard to find a compromise