Project Multistage2015 - Development Thread

[boogabooga]

Centaur uses a separate hydrazine supply for RCS, as probably others do, so I think the high ISP is fine.

 

[DaveS]

Why, the Atlas V Centaur of course!

Not just the Centaur but any large cryogenic stage. This is due the need to settle the propellants at the bottom as they tend to pool elsewhere in the tanks in microgravity. Before engine ignition the settling thrusters are fired to force the propellant to the tank bottoms to ensure that the feedlines aren't sucking a vacuum. This is very bad for the turbopumps as they don't like spinning at infinity RPM as would happen if they were to encounter a no-propellant situation.

 

[ISProgram]

Doesn't the Centaur actually vent gaseous H2 to settle propellants prior to a restart? Either it or the S-IVB...

 

[DaveS]

Doesn't the Centaur actually vent gaseous H2 to settle propellants prior to a restart? Either it or the S-IVB...

Neither does that. The S-IVB used its Auxiliary Propulsion System (APS) thrusters for propellant settling prior to the TLI burn.

 

[ISProgram]

Okay, so after a bit of checking bookmarks, I found my reference, though I had hashed it up because memory.

During its parking orbit, the S-IVB's fuel tank was allowed to vent; the LH2 tank was routed through a "propulsive vent" which provided a small amount of thrust to keep the propellants settled at the aft end of their respective tanks. However, this meant that the propellant tanks had to be repressurized prior to J-2 reignition for its TLI burn. This repressurization system was unique to the Saturn V version of the S-IVB.

Sorry 'bout that.

 

[boogabooga]

As a reference to those that may be interested in working with the new growing particle streams in Multistage2015, I am attaching some screen grabs I took of today's Atlas V mission.

Notice that the exhaust plume starts out very long and straight at liftoff.
Also notice the negative "GROWTHRATE" starting out; the tip is much narrower than the base at the nozzles. The "SRCSIZE" is about the same as the booster diameter.

However, already by about 16km altitude, the plume has a noticeable cone shape in the opposite direction (positive "GROWTHRATE"). The "SRCSIZE" has increased slightly as well.

At some point when the rocket reaches (near?) space, and in a very narrow time window, the flame plume is no longer visible and all that can be seen is exhaust smoke.

 

[boogabooga]

Okay, now that the growing particles are working with the latest patch, here is an Atlas V 401 configuration with some "advanced" particle stream effects that I have been working on. I am trying to get what is seen in the pictures posted above. Please let me know what you think:
(Same textures and meshes as Atlas V 421 posted previously)

[MISC]
cog=8
FOCUS=1
GNC_DEBUG=1

[TEXTURE_LIST]
TEX_1=Exhaust2

[PARTICLESTREAM_1]
NAME=AV7contrail
SRCSIZE=3.0
SRCRATE=100
V0=100.0
SRCSPREAD=0.07
LIFETIME=0.5
GROWTHRATE=-5
ATMSLOWDOWN=2
LTYPE=EMISSIVE
LEVELMAP=LVL_PSQRT
LMIN=0
LMAX=1
ATMSMAP=ATM_PLOG
;AMIN=1e-7
AMIN=0.05
AMAX=1
TEX=contrail3
GROWFACTOR_RATE=4
GROWFACTOR_SIZE=0

[PARTICLESTREAM_2]
NAME=AV7contrail2
SRCSIZE=3.0
SRCRATE=100
V0=100.0
SRCSPREAD=0.07
LIFETIME=0.25
GROWTHRATE=-5
ATMSLOWDOWN=2.0
LTYPE=EMISSIVE
LEVELMAP=LVL_PSQRT
LMIN=0
LMAX=1
ATMSMAP=ATM_PLOG
;AMIN=0.7e-7
AMIN=0.00005
AMAX=1
TEX=contrail3
GROWFACTOR_RATE=35
GROWFACTOR_SIZE=0

[PARTICLESTREAM_3]
NAME=mach
SRCSIZE=7
SRCRATE=120
V0=12
SRCSPREAD=0
LIFETIME=0.25
GROWTHRATE=6
ATMSLOWDOWN=0
LTYPE=DIFFUSE
LEVELMAP=LVL_PSQRT
LMIN=0
LMAX=4
ATMSMAP=ATM_PLOG
AMIN=0.7e-7
AMAX=1
TEX= contrail

[FX_MACH]
pstream=mach
mach_min=0.9
mach_max=1.05
off_1=(0,0,30)
dir=(0,0,-1)

;[BOOSTER_1]
N=1
MeshName="SolarProbe/av501_srb1"
Height=20
Diameter=1.6
EmptyMass=5740
FuelMass=40957
Thrust=1688400 ; 1270000
angle=0
off=(-2.8, 0, -10.77)
rot_speed=(0,1.5,0)
speed=(-7.5,0,0)
BurnTime=84.00
ENG_TEX=Exhaust2
eng_1=(0,0,-8.4)
eng_diameter=0.75
ENG_PSTREAM1=SRBsmoke
ENG_PSTREAM2=SRBflame
CURVE_1=(0,80)
CURVE_2=(94,100)

;[BOOSTER_2]
N=1
MeshName="SolarProbe/av501_srb2"
Height=20
Diameter=1.6
EmptyMass=5740
FuelMass=40957
Thrust=1688400
angle=200
off=(-2.8, 0, -10.77)
rot_speed=(0,1.5,0)
speed=(-7.5,0,0)
BurnTime=84.00
ENG_TEX=Exhaust2
eng_1=(0,0,-8.4)
eng_diameter=0.75
ENG_PSTREAM1=SRBsmoke
ENG_PSTREAM2=SRBflame
CURVE_1=(0,80)
CURVE_2=(94,100)

[STAGE_1]
Height=32.46
Diameter=3.81
EmptyMass=22182.7
FuelMass=284089.0
Thrust=3990000.0
BurnTime=226.6
off=(0,0,0)
speed=(0.,0.,-3.75)
ENG_1=(0,0.757,-20.5)
ENG_2=(0,-0.757,-20.5)
ENG_DIAMETER=1.45
Particles_packed_to_engine= -2
;MeshName="SolarProbe/av501_core"
MeshName="LRO/av_core"
ENG_TEX=Exhaust2
ENG_PSTREAM1=AV7contrail
ENG_PSTREAM2=AV7contrail2
PITCHTHRUST=362000
YAWTHRUST=362000
ROLLTHRUST=36200
ROT_SPEED=0
reignitable=0

[STAGE_2]
Height=12.68
Diameter=3.05
EmptyMass=2243
FuelMass=20830
Thrust=99200
BurnTime=927.7
;off=(0,0,19.85)
off=(0,0,22.85)
;MeshName="NewHorizons/centaur_no_adaptor"
MeshName="LRO/av_centaur"
ENG_1=(0,0,-6.5)
ENG_DIAMETER=1.53
IGNITE_DELAY=10
PITCHTHRUST=17291.7
YAWTHRUST=17291.7
ROLLTHRUST=17291.7
Battery=3.5

[FAIRING]
N=2
MeshName="Beta\av_fair"
Diameter=4.2
Height=12
angle=180
;off=(0,0,22.767)
off=(0,0.0,31.85)
EMPTYMASS=2127

[PAYLOAD_1]
MeshName="Carina"
off=(0.,0.,29.5)
SPEED=(0,0,1)
ROT_SPEED=(0,0,0) 
Module=Vessels\Carina
name=Carina
Diameter=3
Height=5
;Mass=5000
Mass=1630
;Live=1
Render=1

I recommend the following guidance (GPS orbit):

-5=orbit(200, 20200, 55, 1,86.75)
-2.7=engine(0,100,2.7)
254.4=Fairing()

 

[fred18]

Thanks, I'll give it a ride later on today!

in the meantime this is what I'm currently working at for the developer mode

 

[Interceptor]

Thanks, I'll give it a ride later on today!

in the meantime this is what I'm currently working at for the developer mode

Will this feature be in the orbiter 2010 multistage version too?

 

[fred18]

Yes, the plan is to have both releases as much identical as possible.

 

[fred18]

ok looks like finally I made the multipage dialog working so here's a small preview of the shape of the developer mode:

it will be possible to use dialog options to set the launcher parameters (i.e. for payloads as in the pic)

or to view, modify, save and reset directly the ini file of the vehicle:

And to give a check to the log file (I think a log viewer could be an useful plugin for every addon/addon developer anyway)

the direct editor of the ini works fine already, while it will take still a bit of time to make everything work in the dialog interfaces.

One thing that work already (and caused me an headache to make it work :lol is the file picker for meshes and modules. you just click Pick and browse to the file you want to use.

Personally I think that implications for this new method of development are significant.

 

[kerlix]

Being able to pick and load a specific payload "in-sim" without having to set it up first will be a great feature. I've come across something similar before (Kulch's Payload Manager), but this entire package offers so much more flexibility and many more options.


Keep up the great work! :hail:

 

[Cizurator]

I'm really looking foward to convert my Firebird-series HLV to MS2015! Seeing all those great features tempts me to create more and more payloads. And one day, Firebird III...

 

[1987VCRProductions]

I noticed a glitch where if you quicksave and reenter the scenario after separating the payload from the Multistage booster, you'll get a CTD. The only way to fix this is to delete the Multistage craft after payload jettison or to remove it from your quicksave scenario. I've noticed this glitch with older Multistage2 craft as well.

 

[fred18]

I noticed a glitch where if you quicksave and reenter the scenario after separating the payload from the Multistage booster, you'll get a CTD. The only way to fix this is to delete the Multistage craft after payload jettison or to remove it from your quicksave scenario. I've noticed this glitch with older Multistage2 craft as well.

this is curious, especially if it happens with the old multistage2 as well. Which payload are you jettisoning? could you post the quicksave scenario and the ini file you are using? it will be helpful to sort out if anything is going wrong there

---------- Post added at 17:59 ---------- Previous post was at 01:09 ----------

oh boy... this windows programming of reading and writing each parameter into the dialogs is so booooooring....

up to now the following sections are working:
- general ini viewer (and saver)
- general log viewer
- general vehicle update
- payload section
- fairing section (including options to hide full or half of the fairing)
- particle section (including the possibility to test the particle with a slider to change the level)
- Miscellaneous section
- Textures section

missing sections:
- stages
- boosters
- interstages / adapter
- Les
- Effects

I don't think i'll implement the sound section: I never found a single multistage addon which changes the default sounds... and in that case it can be done via ini directly instead of having the dialog window. Also in the Orbiter Beta version, MS15 does not support orbiter sound yet, since it is known to cause issues, I'll update it when a version of orbiter sound for the beta comes out.

 

[fred18]

Booster Section finished...

next on is the stages section, that is not too different. Once finished the stages section I think that the whole work can be considered as 95% completed, since LES and Effects are very easy and I'm thinking of incorporating the interstages section directly inside the stages, I'll see how that comes out. Once all sections will be done I'll publish it here for a week of beta testing by users.

Cheers all

 

[fred18]

Almost there:

Stage section finished... huge one... Includes also interstages

now only a couple of things missing, it's a matter of a few hours of work and this can start to be tested by users! :goodnight: :lol:

 

[BrianJ]

Hi Fred,
outstanding work :thumbup: The autopilot works beautifully and I'm liking the MaxQ contrail effects!
I'm currently using Multistage2015 to simulate the upcoming Cygnus OA-4 launch on an AtlasV.
I'm using an .ini and guidance.txt (slightly modified) posted earlier by boogabooga (thanks).

Here's the guidance.txt

-5=orbit(250, 325, 51.65, 1,87)
-2.7=engine(0,100,2.7)
254.4=Fairing()

The guidance.txt should ramp the engine up from 0% to 100% throttle during 2.7s - but the throttle only goes to 96%.
It looks like the same problem the old multistage2 used to have.

This fixes it

-5=orbit(250, 325, 51.65, 1,87)
-2.7=engine(0,100,2.7)
[COLOR="Red"]0=engine(100,100,1)[/COLOR]
254.4=Fairing()

Here is my AtlasV .ini for reference

[MISC]
cog=8
FOCUS=1
GNC_DEBUG=1

[TEXTURE_LIST]
TEX_1=Exhaust2

[PARTICLESTREAM_1]
NAME=AV7contrail
SRCSIZE=4.0
SRCRATE=100
V0=100.0
SRCSPREAD=0.07
LIFETIME=0.4
GROWTHRATE=-3
ATMSLOWDOWN=1
LTYPE=EMISSIVE
LEVELMAP=LVL_PSQRT
LMIN=0
LMAX=1
ATMSMAP=ATM_PLOG
;AMIN=1e-7
AMIN=0.05
AMAX=1
TEX=contrail3
GROWFACTOR_RATE=4
GROWFACTOR_SIZE=0

[PARTICLESTREAM_2]
NAME=AV7contrail2
SRCSIZE=4.0
SRCRATE=100
V0=100.0
SRCSPREAD=0.07
LIFETIME=0.4
GROWTHRATE=-3
ATMSLOWDOWN=1
LTYPE=EMISSIVE
LEVELMAP=LVL_PSQRT
LMIN=0
LMAX=1
ATMSMAP=ATM_PLOG
;AMIN=0.7e-7
AMIN=0.00005
AMAX=1
TEX=contrail3
GROWFACTOR_RATE=35
GROWFACTOR_SIZE=0

[PARTICLESTREAM_3]
NAME=mach
SRCSIZE=4
SRCRATE=50
V0=1
SRCSPREAD=0.1
LIFETIME=0.125
GROWTHRATE=0
ATMSLOWDOWN=5
LTYPE=EMISSIVE
LEVELMAP=LVL_PSQRT
LMIN=0
LMAX=4
ATMSMAP=ATM_PLOG
AMIN=0.7e-7
AMAX=1
TEX= contrail

[FX_MACH]
pstream=mach
mach_min=0.8
mach_max=1.2
off_1=(0,0,29.5)
dir=(0,0,-1)

[STAGE_1]
Height=32.46
Diameter=3.81
EmptyMass=22182.7
FuelMass=284089.0
Thrust=3990000.0
BurnTime=226.6
off=(0,0,0)
speed=(0.,0.,-3.75)
ENG_1=(0,0.857,-20.5)
ENG_2=(0,-0.857,-20.5)
ENG_DIAMETER=2
Particles_packed_to_engine= -2
MeshName="LRO/av_core"
ENG_TEX=Exhaust2
ENG_PSTREAM1=AV7contrail
ENG_PSTREAM2=AV7contrail2
PITCHTHRUST=362000
YAWTHRUST=362000
ROLLTHRUST=36200
ROT_SPEED=0
reignitable=0

[STAGE_2]
Height=12.68
Diameter=3.05
EmptyMass=2243
FuelMass=20830
Thrust=99200
BurnTime=927.7
off=(0,0,22.85)
MeshName="LRO/av_centaur"
ENG_TEX=Exhaust2
ENG_1=(0,0,-7)
ENG_DIAMETER=1.53
IGNITE_DELAY=10
PITCHTHRUST=17291.7
YAWTHRUST=17291.7
ROLLTHRUST=17291.7
Battery=3.5

[FAIRING]
N=2
MeshName="AV061\av_fair"
Diameter=4.2
Height=12
angle=180
off=(0,0.0,31.85)
EMPTYMASS=2127

[PAYLOAD_1]
MeshName="Orbital\Cygnus"
MASS=5649
off=(0,0,31.5)
SPEED=(0,0,1)
ROT_SPEED=(0,0,0) 
Module=Vessels\AV061\Cygnus
name=Cygnus
Diameter=3
Height=5
Live=1

I'm using the Multistage2015 package downloaded from OH 2 or 3 days ago.

Many thanks,
Brian

 

[fred18]

Hi Fred,
outstanding work :thumbup: The autopilot works beautifully and I'm liking the MaxQ contrail effects!

Thanks man! :tiphat:

The guidance.txt should ramp the engine up from 0% to 100% throttle during 2.7s - but the throttle only goes to 96%.
It looks like the same problem the old multistage2 used to have.


This fixes it

-5=orbit(250, 325, 51.65, 1,87)
-2.7=engine(0,100,2.7)
[COLOR="Red"]0=engine(100,100,1)[/COLOR]
254.4=Fairing()

I know, I think I replicated the very same Vinka's function there and it's difficult to find a solution because if the interpolation interval is too short the interpolation may finish before the next simulation step without completing itself.

Your solution is the best way for the time being, I don't have any other in my mind for now :thumbup:

I'm using the Multistage2015 package downloaded from OH 2 or 3 days ago.

Many thanks,
Brian

Yep, fine! In that file there is a small bug relevant to grwoing particle effect that has already been solved and a small patch can be downloaded from here:
http://www.orbiter-forum.com/showthread.php?p=518995&postcount=28

The OH version will be updated with this fix as soon as I'm over with the Developer Mode Dialogs (not too much work missing there).

All other core functionalities will not be touched again so all the development ongoing won't be affected at all!

Cheers!

Fred

 

[Marg]

But launch of SLS is still strange, after fire is on, rocket behaves strangely on the pad - it leans off vertical line and rotates. Only after a few seconds it corrects and goes up normally...