Project Multistage2015 - Development Thread

[gattispilot]

So I did some modification. But the 2nd stage doesn't fire off. Using the first only doesn't get it to 200 orbit.

[MISC]
cog=28.500
GNC_Debug=0
Telemetry=0
Focus=0
Thrust_real_pos=0
Vertical_Angle=0.000

[TEXTURE_LIST]
TEX_1=Exhaust_atsme

[PARTICLESTREAM_1]
Name=vent
amin =0.150
amax =1.000
atmslowdown =3.000
growthrate =1.200
lifetime =4.500
lmax =0.500
lmin =0.000
srcrate =15.000
srcsize =0.400
v0 =1.000
ltype =EMISSIVE
atmsmap =ATM_FLAT
levelmap =LVL_PSQRT
tex =contrail
Srcspread=0.000

[PARTICLESTREAM_2]
NAME=mach
SRCSIZE=7.000
SRCRATE=120.000
V0=12.000
SRCSPREAD=0.000
LIFETIME=0.250
GROWTHRATE=6.000
ATMSLOWDOWN=0.000
LTYPE=EMISSIVE
LEVELMAP=LVL_PSQRT
LMIN=0.000
LMAX=4.000
ATMSMAP=ATM_FLAT
AMIN=0.600
AMAX=1.000
TEX=contrail4

[FX_VENT]
pstream=vent
off_1=(4.200,0.000,35.000)
dir_1=(1.000,0.000,0.000)
time_fin_1=-15.000
off_2=(0.000,4.200,15.000)
dir_2=(0.000,1.000,0.000)
time_fin_2=-25.000

[FX_MACH]
pstream=mach
mach_min=0.900
mach_max=1.100
off_1=(0.000,0.000,70.000)
off_2=(6.777,0.000,20.000)
off_3=(-6.777,0.000,20.000)
dir=(0.000,0.000,-1.000)

[BOOSTER_1]
N=1
MeshName=DELTALEFTBOOSTER
Height=50.000
Diameter=5.1
EmptyMass=26400 
FuelMass=202000 
Thrust=3140000
angle=3.142
off=(-5.1,0.500,4.7500)
BurnTime=150
eng_1=(0.000,0.000,-18.000)
eng_diameter=1
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=DELTARIGHTBOOSTER
Diameter=5.1
EmptyMass=26400 
FuelMass=202000 
Thrust=3140000
angle=3.142
off=(5.1,0.000,4.75000)
BurnTime=150
eng_1=(0.000,0.000,-18.000)
eng_diameter=1
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=43.03
Diameter=5.1
EmptyMass=26400 
FuelMass=202000 
Thrust=3140000
BurnTime=367
off=(0.000,0.000,4.700)
MeshName=DELTA4CBCNEW
eng_1=(0,0,-18)
eng_diameter=1
PITCHTHRUST=14193633.100 
YAWTHRUST=14193633.100 
speed=(0.000,0.000,-10.000)
ENG_PSTREAM1=exhaust
battery=1.500
Reignitable=1
Eng_tex=
Eng_pstream2=contrail
Eng_dir=(0.000,0.000,1.000)
Module=Stage
Rot_speed=(0.000,0.000,0.000)

[STAGE_2]
Height=43.03
Diameter=5.1
EmptyMass=3490 
FuelMass=27220 
Thrust=110000
BurnTime=449.000
off=(0.000,0.000,34.4)
MeshName=SLS_2016/SLS_ICPS
eng_1=(0,0,-4.5)
eng_diameter=1
PITCHTHRUST=56774532.400 
YAWTHRUST=56774532.400 
speed=(0.000,0.000,-19.000)
ENG_PSTREAM1=
battery=1.500
Reignitable=1
Eng_tex=
Eng_pstream2=
Eng_dir=(0.000,0.000,1.000)
Module=Stage
Rot_speed=(0.000,0.000,0.000)

[FAIRING]
Meshname=SLS_2016\SLSTALONFAIR
Off=(0.000,0.000,43.75)
N=3
Angle=90.000
Height=6.000
Diameter=8.000
EmptyMass=1383.000
Module=stage
Speed=(8.000,0.000,0.000)
Rot_Speed=(0.700,0.000,0.000)

[PAYLOAD_1]
MeshName=TALON
off=(0.000,0.000,45.50)
Diameter=5.000
Height=8.000
MASS=23820.000
Module=TALON
Name=TALON
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

[LES]
Meshname=SLS_2016\TALONLES
Off=(0.000,0.000,45.450)
Height=13.000
Diameter=5.000
EmptyMass=5044.000
Module=stage
Speed=(0.000,2.000,30.000)
Rot_speed=(0.000,0.100,0.000)

guidance file:

Multistage 2015 Automatically Generated Guidance File
Vehicle: delta4hvy
-10.000 =orbit(200.00,200.00,-29.59,1.00,89.3,0.00)
-5.000 =engine(0.00,110.00,5.00,0.00,0.00,0.00)
45.000 =fairing(75.00,0.00,0.00,0.00,0.00,0.00)
50.000 =les(85.00,0.00,0.00,0.00,0.00,0.00)
50.000 =engine(100.00,85.00,3.00,0.00,0.00,0.00)

scn after 1stage seperation:

DELTA4:Multistage2015
  STATUS Orbiting Earth
  RPOS 5089591.549 3826718.844 -1429797.588
  RVEL 4000.2779 -3086.5733 4233.6828
  AROT -32.249 -45.693 67.419
  VROT -0.3078 -0.0042 0.0046
  AFCMODE 7
  PRPLEVEL 0:1.000000
  NAVFREQ 0 0 0 0
  XPDR 0
  CONFIG_FILE Config\Multistage2015\DELTA4HVY4.ini
  GUIDANCE_FILE Config\Multistage2015\Guidance\DELTA4HVY_GNC.txt
  CONFIGURATION 1
  COMPLEX 
  CURRENT_BOOSTER 3
  CURRENT_STAGE 2
  CURRENT_INTERSTAGE 1
  CURRENT_PAYLOAD 1
  FAIRING 0
  MET 442.596
  GNC_RUN 1
  BATTERY 5376.588421
  GROWING_PARTICLES 
  STAGE_IGNITION_TIME 419.184843
  STAGE_STATE 1
  TELEMETRY_FILE Config\Multistage2015\Telemetry\SLS_57310.61_TLM.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 -80.5908600 28.6371940
  HEADING 0.00
  ALT 19.997
  AROT 61.688 4.494 8.275
  AFCMODE 7
  NAVFREQ 0 0
  TARGET DELTA4
END
TALON:TALON
  JOINT1 1.0000
  JOINT2 0.3051
  JOINT7 1.0000
  MODE 0
  HGA 0 0.0000
  HATCH 0 0.0000
  BEACON 1
  EVA 0
  STATUS Orbiting Earth
  RPOS 5089599.492 3826714.706 -1429791.030
  RVEL 4000.2779 -3086.5733 4233.6828
  AROT -32.249 -45.693 67.419
  VROT -0.3078 -0.0042 0.0046
  ATTACHED 1:0,DELTA4
  AFCMODE 7
  PRPLEVEL 0:1.000000 1:1.000000
  NAVFREQ 0 0
  XPDR 0
END
DELTA4CBCNEW:Stage
  STATUS Orbiting Earth
  RPOS 5089383.033 3826793.664 -1429940.790
  RVEL 3992.3746 -3083.7403 4228.2576
  AROT -32.244 -45.693 67.415
  VROT -0.3076 -0.0039 0.0046
  AFCMODE 7
  NAVFREQ 0 0
END
END_SHIPS

 

[fred18]

just add this into stage_2 section:

ignite_delay=0.1000

it seems he doesn't like the ignite_delay to be 0, I'll check why, in the meantime use that

 

[gattispilot]

That fixed that.

Tiring to get the boosters when out of fuel to jettison on the correct side.

[BOOSTER_1]
N=1
MeshName=DELTALEFTBOOSTER
Height=50.000
Diameter=5.1
EmptyMass=26400 
FuelMass=202000 
Thrust=3140000
angle=3.142
off=(-5.1,0.500,4.7500)
BurnTime=150
eng_1=(0.000,0.000,-18.000)
eng_diameter=1
ENG_PSTREAM1=exhaust
Speed=(15.000,0.000,0.000)
Rot_speed=(-15.000,0.000,0.000)
Eng_tex=
Eng_pstream2=contrail

[BOOSTER_2]
N=1
MeshName=DELTARIGHTBOOSTER
Diameter=5.1
EmptyMass=26400 
FuelMass=202000 
Thrust=3140000
angle=3.142
off=(5.1,0.000,4.75000)
BurnTime=150
eng_1=(0.000,0.000,-18.000)
eng_diameter=1
ENG_PSTREAM1=exhaust
Speed=(15.000,0.000,0.000)
Rot_speed=(15,0.00,0.000)
Eng_tex=
Eng_pstream2=contrail

 

[fred18]

Tiring to get the boosters when out of fuel to jettison on the correct side.

try to learn from the example / examples. use Multistage2 examples, there are hundreds of them

 

[boogabooga]

Okay, I have some time today (I've been super busy this month) and I wanted to address this:

All right, I'd say that I agree with part of what you said but not entirely.

no, the point is that the orbiting vessel is not an inertial system, so centrifugal apparent force will apply. This is due to the fact that the system is constantly accelerated by gravity and the resulting apparent centrifugal force will be equal to F=m*v^2 / r. That's why orbital velocity has an impact to 0g feeling of the orbiting astronauts. Virgin Galactic will use free fall, which applies the same concept, as the vomit comet airplan.
I've made tons of calculations about this in the past (both for real life work and for orbiter), that was silly of me not remembering this immediatly.

NO NO NO. You fundamentally misunderstand this. Yes, it is true that if you are going really fast there will be centrifugal (and possibly Euler) fictitious forces. But that has absolutely zero bearing on WHY there is "0g feeling." Orbit IS a kind of free fall. It's not different from Virgin Galactic in this way. Also, if you were correct, then the Apollo astronauts on a highly elliptical orbit would not have 0g feeling when fictitious and gravitational forces were NOT equal. That was not the case.


The key idea that you are missing is that body forces are not counted when you calculate "g-force." Please read: https://en.wikipedia.org/wiki/G-force

Please bring this up in physics forum if you do not believe this.

Anyway, the thrust + drag calculation was correct in the module. Stick with that.

Wondering if you plan to make this correction (plus blue-screen camera) for the Orbiter 2010 version? I get that you are busy with generic vessel.

 

[fred18]

Okay, I have some time today (I've been super busy this month) and I wanted to address this:



NO NO NO. You fundamentally misunderstand this. Yes, it is true that if you are going really fast there will be centrifugal (and possibly Euler) fictitious forces. But that has absolutely zero bearing on WHY there is "0g feeling." Orbit IS a kind of free fall. It's not different from Virgin Galactic in this way. Also, if you were correct, then the Apollo astronauts on a highly elliptical orbit would not have 0g feeling when fictitious and gravitational forces were NOT equal. That was not the case.


The key idea that you are missing is that body forces are not counted when you calculate "g-force." Please read: https://en.wikipedia.org/wiki/G-force

Please bring this up in physics forum if you do not believe this.

Anyway, the thrust + drag calculation was correct in the module. Stick with that.

Wondering if you plan to make this correction (plus blue-screen camera) for the Orbiter 2010 version? I get that you are busy with generic vessel.

I think we are partly talking about two aspects of the same thing, because I'm really really sure that I'm right, and not "fundamentally misunderstanding". We are still talking about acceleration perceived on a vessel/spacecraft. If you say that there is no contact forces is fine, no reactions and the astronauts keeps falling, but this is not "just happening", it happens because the centripetal acceleration is equal to the apparent centrifugal acceleration due to speed around earth. This is the very reason why on ISS astronauts do not experience "zero G" but "MICRO gravity", because the ISS orbit is elliptical.

Please bring this up in physics forum if you do not believe this.

first answer: this comes from the notes of my physics prof of engineering (some years ago but still there )

second answer:

from https://phys.org/news/2016-04-microgravity.html

Another way to achieve "free fall" is to put things into orbit (such as the International Space Station). A force, called the centrifugal force, "pushes" an object travelling in a circle away from the centre of the motion. Go around a corner fast on your bike and if you don't lean into the "bend" you'll find it difficult to stay on the bike and steer at the same time – lean too far and the wheels will get "pushed out" from underneath you. It's all a matter of balancing forces.

just google "orbit centrifugal force" and you'll find thousands of examples.
like this:
http://www2.mae.ufl.edu/~uhk/SUNMASS2.jpg

two easy additions:
let's take a perfect circular orbit at 350 km, what whould be the velocity needed?

easy: centrifugal force equal to gravitational force, therefore centrifugal acceleration equal to gravity acceleration at that height. g at 350 km is about 8.82 m/s2, so speed can be found by doing the inverse of centripetal acceleration equation a=v^2/r --> v=sqrt(a*r) --> v= 7'701.8 m/s which is the average speed of the ISS.

Same concept applied on wikipedia page for the geostationary orbit:
https://en.wikipedia.org/wiki/Geostationary_orbit

then the Apollo astronauts on a highly elliptical orbit would not have 0g feeling when fictitious and gravitational forces were NOT equal

oh yeah, that was absolutely the case, I don't have time to make calculations now but I'll get back on this with precise results.

Wondering if you plan to make this correction (plus blue-screen camera) for the Orbiter 2010 version? I get that you are busy with generic vessel.

Yes I have it in pipeline. Not this week since I'm out the full week, but as soon as I come back



Going back to the point I think we are discussing two aspects of the same topic: you are stating that the absence of contact forces generates zero G. I say that is true, but that happens for a reason which is the apparent centrifugal force.

 

[boogabooga]

I think we are partly talking about two aspects of the same thing, because I'm really really sure that I'm right, and not "fundamentally misunderstanding".

We're not. You're talking about something that doesn't matter.

We are still talking about acceleration perceived on a vessel/spacecraft.

"Perceived" is probably the key word of misunderstanding. There is a concept of body forces. Body forces can cause acceleration, but you don't "feel" that acceleration. As in, they will not be registered by an accelerometer. If only body forces are acting on you, you feel "weightless".

If you say that there is no contact forces is fine, no reactions and the astronauts keeps falling, but this is not "just happening", it happens because the centripetal acceleration is equal to the apparent centrifugal acceleration due to speed around earth. This is the very reason why on ISS astronauts do not experience "zero G" but "MICRO gravity", because the ISS orbit is elliptical.

Sure, when gravitational acceleration is equal to the centrifugal acceleration, you will be in a circular orbit and your trajectory will be such that you will not get closer or further from the earth's surface. But that has NOTHING to do why there is "zero G" feeling. Both gravity and the fictitious centrifugal force are body forces and DO NOT CONTRIBUTE TO the calculation of "g-force." It is NOT a requirement for micro gravity sensation that there are any centrifugal forces at all. Both sounding rockets and evacuated drop tunnels can temporarily produce micro gravity without any problems.

The MICRO gravity feeling has nothing to do with how elliptical the orbit is. It's tiny bit of air friction and some tidal forces, etc.

You've convinced yourself of something false.

second answer:

from https://phys.org/news/2016-04-microgravity.html

The article is just describing why you stay in orbit, NOT why there is "zero-g" feeling. Two different things. You've misunderstood.

just google "orbit centrifugal force" and you'll find thousands of examples.
like this:
http://www2.mae.ufl.edu/~uhk/SUNMASS2.jpg

Sure. But that's a red herring. Has nothing to do with why there is "zero-g" feeling.

 

[fred18]

Let s just have the final explanation on this that will make both agree:

Body forces and contact forces are just a way to get relativity concept easier.

Point is: a body in orbit moves along a geodetic, which is straight line in bended space time. Straight line = no forces at all. So variations are not perceived (that was a mistake of mine). But my concept is that a body gets to move along a geodetic because of its velocity, that s why acceleration was so important and on this i was right.

I think we both messed up one thing: we skipped from forces to accelerations many times (the ms2015 command was about acceleration, but we soon end up talking about forces and then forth and back) so in terms of accelerations all the accelerations should be accounted since they are there, even the centrifugal one (which determines the trajectory as well). In terms of forces just the actual forces. And even though is always difficult to see it: gravity is not a real force, it s just a bending of space time that makes body moves towards one another so in our case i was computing the correct acceleration, but was using it for forces evaluation. Do you agree on this?

 

[asbjos]

I haven't used this addon (I'm away from my Orbiter installation this summer), and don't know exactly what the intention and implementation for vessel acceleration/G's is. I tried to look up in the source code supplied for the addon, but couldn't find any references.

Anyway, here's the simple formula for finding it, which I use in Vessel Load MFD

VESSEL *v = oapiGetFocusInterface();
double m = v->GetMass();
VECTOR3 F, W;
v->GetForceVector(F);
v->GetWeightVector(W);
VesselAcceleration = length((F - W) / m); // m/s^2
VesselG = VesselAcceleration / G;

This VesselG value is what is felt by an astronaut onboard (0 G while in orbit, 1 G when landed on the Earth, 0.16 G when landed on the Moon, more than 1 G when launching from the Earth, etc. ...).
It comes from what forces are acting on you (F, which sums up the forces from drag, engine thrust, normal forces from surfaces, and others) other than the force acting on all other objects at the same position (-W, i.e. gravity).

I don't want to engage too much into your discussion, as it's hard for a lousy Norwegian student to teach others in written form in English. But explaining with general relativity is excessive, especially when we are talking about a simulator where it's not implemented

But yes, the "effective" acceleration from the change in position for the rocket, would be e.g. 0.63 G's, and the surface MFD would then probably display an acc of ~6.3 m/s^2, but the astronauts or probes on board would experience a more crushing force, resulting in a acceleration of ~16.3 m/s^2 with respect to a freely falling object outside their window.

I hope this is a meaningful contribution to your discussion.

 

[Face]

Surely I can for simplicity take the thrust, divide it by the mass to obtain the acceleration, but then sitting on the ground it would be 0g, while it should be 1g, right? I was just thinking how to get the overall correct result. I've made a new function to calculate Gs, which gives exactly 1G on the ground, but still I get the difference between thrust and weight while climbing.
:shifty:

I'd do it like so:

VECTOR3 fv, wv, gcalcv;
GetForceVector(fv);
GetWeightVector(wv);
gcalcv=fv-wv;
double gcalcvl=length(gcalcv)/GetMass()/9.81;

It will show 1G while landed, 0G in free fall, Gs on climbing, sinking, turning.

I think the discussion about what is force and what not is academic in this case. What counts is how you'd simulate a G-meter, does it not?

EDIT: That's exactly what asbjos posted above. Somehow I missed that completely, sorry.

 

[gattispilot]

I am going to ask a dumb question. I know you can set the ship to orbit at a certain height. But then can you set the 2nd stage to fire to go to Mars,....

 

[Donamy]

If it's left as it's own vessel, I don't see why not, or that it should require Multistage.

 

[fred18]

I am going to ask a dumb question. I know you can set the ship to orbit at a certain height. But then can you set the 2nd stage to fire to go to Mars,....

Theoretically is possible: if you can get the proper MET, attitude and burn time from IMFD or transX you can use a combination of guidance commands, like "attitude" and "engine" in your guidance program to emulate them, but I'm afraid it will lead to big approximations. So my best advice is to use IMFD or transX anyway. if you want you can try what I said here above.

 

[gattispilot]

If it's left as it's own vessel, I don't see why not, or that it should require Multistage.

Not sure what you mean? Like for the JWST or MSL. I can make the meshes for the Delta4 or Altas. But can I set the guidance to get the vessel to the target or do I need another program?

 

[Donamy]

I think Fred18, just answered that for you, better than I.

 

[gattispilot]

Thanks. Ok then I than I am not sure how to approach this.

Like the MSL it used an Altas 541. I can make the meshes to launch the msl. But not sure if I can get to Mars.

I might let smarter minds work on this.

 

[fred18]

Hi there,

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

Fred

 

[fred18]

Did anyone had the chance to test those modules?

 

[boogabooga]

I didn't see it until just now. I will try to test this weekend. But I am really busy until mid July.

 

[fred18]

I updated on OH both 2010P1 and 2016 version with the following:
- Camera bug fixed
- Ignite_delay=0 bug fixed
- SLS.ini now is the boogabooga file
- logics for hangar, crawler and ramp creation now correct for any orbiter version, no dirty scenario hacks anymore.

Hope everything works fine!

Cheers