Scenario Velcro Addon Help

[AlfalfaQc]

Hello everyone, I am currently trying to learn how Velcro rocket works but I have some problems. I want to put the Dragon capsule on top of the Delta IV Heavy (from the EELV Velcro Add-On), but it doesn't work. I tried the PAYLOAD command, but the vessel doesn't appear (it's invisible) but nothing crashes. When I use SERIESBURN, the simulation simply won't load and crash. I searched on the forum for some tutorials but the only advice I found was "Look at the files and try to learn it" but it obviously doesn't work for me. If someone could help me understand a bit better how SERIESBURN and PAYLOAD work, it would be nice.

Thanks in advance

 

[garyw]

Can you post the scenario or the velcro config your using? it's hard to help without seeing it.

 

[N_Molson]

You should not use PAYLOAD for something like a capsule. Use SERIESBURN and add IGNITENEXT 0 to allow a manual separation.

Now for the crashing problem, try to reproduce the situation with a vessel that comes with Orbiter, like the ShuttlePB. If it works with the PB, then your config and scn files are correct, and you should contact the author of the Dragon addon to understand what's going on.

 

[AlfalfaQc]

Ok, I tried with the standard DG and it works well until the separation of the DG where it CTD. Here's the ship part of the SCN file:

BEGIN_SHIPS
GL-01eltaGlider
STATUS Landed Earth
BASE Cape Canaveral:1
HEADING 150.00
PRPLEVEL 0:1.000 1:1.000
NAVFREQ 402 94 0 0
XPDR 0
NOSECONE 0 0.0000
GEAR 1 1.0000
AIRLOCK 0 0.0000
END
DeltaStg2:Velcro/D4Stg2_5m
STATUS Landed Earth
BASE Cape Canaveral:6
HEADING 270.00
TGT_HEADING 095.0
FUEL 1.000
CONFIGURATION 0
SCREENHEIGHT 250.0
; PITCHMULTIPLE 0.25
CAMERA 0 0 20.0
Fairing 2 2.0 4.0 0.0 0.0
SERIESBURN 0 GL-01 0.0 0.0 -3.0 0.0 1.0 0.0
END
DeltaCBC:Velcro/CBC
STATUS Landed Earth
BASE Cape Canaveral:6
HEADING 270.00
TGT_HEADING 095.0
FUEL 1.000
CONFIGURATION 0
MaxMainThrust = 1888270.35 ; Throttle setting at 57% throughout
SCREENHEIGHT 225.0
MINPITCH 10.0
CAMERA 0 0 50.0
SERIESBURN 0 DeltaStg2 0.0 0.0 1.2 0.0 1.0 0.0
PAYLOAD Int Velcro/Parts/Int_CBC_5m Velcro/Parts/Int_CBC_5m 0 0 0 0.1 0 0.0 1.0
END
Dummy1:Velcro/DeltaIVDummyBoost ; Simulates the high-throttle portion from ignition to t+60
STATUS Landed Earth
BASE Cape Canaveral:6
HEADING 0.00
TGT_HEADING 095.0
FUEL 1.000
CONFIGURATION 0
PRIMEBOOSTER 0
CENTERTHRUST 1
BOOSTERBURN 1 DeltaCBC 0.75 0.0 0.0 0.0 0.0 -1.0 0.0
END
Dummy2:Velcro/DeltaIVDummyBoost ; Simulates the throttle-up at T+251 sec.
STATUS Landed Earth
BASE Cape Canaveral:6
HEADING 0.00
TGT_HEADING 095.0
FUEL 1.000
CONFIGURATION 0
PRIMEBOOSTER 0
CENTERTHRUST 1
DELAYSTART 251.0
BOOSTERBURN 1 DeltaCBC 0.01 0.0 0.0 0.0 0.0 -1.0 0.0
END
LRB1:Velcro/CBC_LRB_L
STATUS Landed Earth
BASE Cape Canaveral:6
HEADING 0.00
TGT_HEADING 095.0
FUEL 1.000
CONFIGURATION 0
PRIMEBOOSTER 0
CENTERTHRUST 1
PARALLELBURN 1 DeltaCBC 1.5 0.0 1.0 1.0 0.0 0.0
END
LRB2:Velcro/CBC_LRB_R
STATUS Landed Earth
BASE Cape Canaveral:6
HEADING 0.00
TGT_HEADING 095.0
FUEL 1.000
CONFIGURATION 0
PRIMEBOOSTER 0
CENTERTHRUST 1
PARALLELBURN 1 DeltaCBC -1.5 0.0 1.0 -1.0 0.0 0.0
END
END_SHIPS

I don't know where to put the IGNITENEXT command.

 

[N_Molson]

; PITCHMULTIPLE 0.25

Get rid of that one.

Fairing 2 2.0 4.0 0.0 0.0

That one too.

Add IGNITENEXT 0 anywhere in DeltaStg2:Velcro/D4Stg2_5m.

Any improvements with those modifications ?

 

[AlfalfaQc]

Yeah awesome it works!! Thanks a lot guys!

What are the two lines I got rid of do exactly? Why were they crashing the simulation?

 

[N_Molson]

; PITCHMULTIPLE 0.25

The ";" is a suspect to me, especially at the beginning of the line. Might fool the parser.

Fairing 2 2.0 4.0 0.0 0.0

This defines a fairing. Useless as you don't need one, and potentially dangerous as there are no fairing "vessels" in the scenario. Also, if that line is present, you need to add "Fairing1 (name)" and "Fairing2" (name), here it isn't the case and is another crash suspect.

IGNITENEXT 0

Prevents Velcro Rockets from trying to "ignite" the DeltaGlider engines. IGNITENEXT can give unpredictable results with vessels like the DG that have custom modules (.dll), because inside the .dll, there is a code running that may conflict with the Velcro instruction (to make things simple).

 

[AlfalfaQc]

Ah ok I see, anyway, it worked fine. Now I just have to play around with the scenarios to try to stick stuff with stuff to make awesome stuff :lol: . I also tried the PAYLOAD option with some satellites that come with de Delta IV Heavy add-on, and it worked well. I also have to figure out how to place those rocket on a good launchpad.

Thanks for the help!

 

[N_Molson]

I also have to figure out how to place those rocket on a good launchpad.

Use PADBIAS x, where x is the height at which you want the rocket to stand. To get the right location of the pads, use Google Earth and copy down the decimal long/lat coordinates in the scenario file (POS xx.xxx yy.yyy)

 

[AlfalfaQc]

Little update: I tried to put the Dragon on top of the Delta IV Heavy and it works perfectly!

Thanks again!