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Re: Shuttle launch problems

Postby Vinny002 » Thu Jul 04, 2019 7:46 am

I was thinking maybe I can have you look at my FG space shuttle using remote access.
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Re: Shuttle launch problems

Postby legoboyvdlp » Thu Jul 04, 2019 8:13 am

Vinny002 wrote in Wed Jul 03, 2019 10:11 pm:Let me help you clarify this, when the FG appears, the space shuttle stack exploded with the red screen appeared for a few, the SRBs is already ignited, and the SSMEs is not burning.


Are you sure you are using the right Shuttle? It would be rather annoying if you are using Herby's Shuttle after all this which as I recall starts horizontal?

Where did you get your Shuttle - from fgaddon, from the launcher, from flightgear.org, from elsewhere?
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Re: Shuttle launch problems

Postby eatdirt » Thu Jul 04, 2019 9:54 am

I think he is using fgfs --launcher and select everything from the menu, which, personally, I've never tested before.

But I've just tried, with 2018.3.2, Shuttle downloaded and selected from the menu, as well as the airport (KTTS) and the place "South Ramp". Starting in Paused, the Shuttle is indeed at some high altitude initially. Then, unpausing, it goes down, but in my case, it just go down and stops where it should. I do not see any issues. I've tried with scenery enabled or disabled, even disabled, the Shuttle correctly goes to the right attitude in water. The only thing I've spotted is that the position on the pad is a bit weird (that's for south ramp):

Image





Vinny, you must provide precise enough details such that we can help, many people asked you this already! What's your choices on the location at KTTS (south ramp? runway?).

And also, are you an adult? just to know which kind of questions we can ask. For instance, you should not select a starting point at 6000fts of altitude with a wind of 120kts, that's for landing only...

Cheers,
Chris.
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Re: Shuttle launch problems

Postby eatdirt » Thu Jul 04, 2019 9:59 am

I meant to say my space shuttle stack falls to the horizontal position after ignition.


Other possibility, you have a joystick/throttle control set to non-zero value. If this is the case, the SRB ignites without the MPS (and possibly the OMS if the throttle control is high enough). Either set the joystick throttle to 0, or unplug it and try again.
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Re: Shuttle launch problems

Postby wkitty42 » Thu Jul 04, 2019 2:24 pm

eatdirt wrote in Thu Jul 04, 2019 9:54 am:But I've just tried, with 2018.3.2, Shuttle downloaded and selected from the menu, as well as the airport (KTTS) and the place "South Ramp". Starting in Paused, the Shuttle is indeed at some high altitude initially. Then, unpausing, it goes down, but in my case, it just go down and stops where it should. I do not see any issues. I've tried with scenery enabled or disabled, even disabled, the Shuttle correctly goes to the right attitude in water. The only thing I've spotted is that the position on the pad is a bit weird (that's for south ramp):

using your method, i'm testing this now just for S&Gs... i think you're likely right about how the poster is starting his sim... it makes perfect sense that they'll just load up, select the shuttle and give it a go...

it also sounds like we need a ""special"" parking location of 39A and 39B placed on the two launch pads the shuttle used? that should be easy enough to do with an updated ground net... maybe...
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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Re: Shuttle launch problems

Postby wkitty42 » Thu Jul 04, 2019 2:27 pm

right off the bat i get the following... this is using the latest craft available in FGAddon...
Code: Select all

In file /home/myuser/flightgear-dev/fgaddon-ng/Aircraft/SpaceShuttle/Systems/rcs_control.xml: line 766
<sum> only has one argument which makes it a no-op.
Its argument will be evaluated but <sum> will not be applied to the result.

In file /home/myuser/flightgear-dev/fgaddon-ng/Aircraft/SpaceShuttle/Systems/rcs_control.xml: line 789
<sum> only has one argument which makes it a no-op.
Its argument will be evaluated but <sum> will not be applied to the result.

In file /home/myuser/flightgear-dev/fgaddon-ng/Aircraft/SpaceShuttle/Systems/rcs_control.xml: line 812
<sum> only has one argument which makes it a no-op.
Its argument will be evaluated but <sum> will not be applied to the result.

In file /home/myuser/flightgear-dev/fgaddon-ng/Aircraft/SpaceShuttle/Systems/computations.xml: line 695
<max> only has one argument which makes it a no-op.
Its argument will be evaluated but <max> will not be applied to the result.

In file /home/myuser/flightgear-dev/fgaddon-ng/Aircraft/SpaceShuttle/Systems/computations.xml: line 728
<max> only has one argument which makes it a no-op.
Its argument will be evaluated but <max> will not be applied to the result.

In file /home/myuser/flightgear-dev/fgaddon-ng/Aircraft/SpaceShuttle/Systems/computations.xml: line 759
<max> only has one argument which makes it a no-op.
Its argument will be evaluated but <max> will not be applied to the result.

In file /home/myuser/flightgear-dev/fgaddon-ng/Aircraft/SpaceShuttle/Systems/autopilot.xml: line 3415
<product> only has one argument which makes it a no-op.
Its argument will be evaluated but <product> will not be applied to the result.

In file /home/myuser/flightgear-dev/fgaddon-ng/Aircraft/SpaceShuttle/shuttle.xml: line 3054
<product> only has one argument which makes it a no-op.
Its argument will be evaluated but <product> will not be applied to the result.

  405.19 [ALRT]:input      Could not find 'Effects/schemes.xml'
[...]
  739.25 [ALRT]:general    Failed to find a parking at airport KTTS:South_ramp


perhaps the latest code can be pushed?

[time passes]

wow! i knew that the craft started in the air and dropped onto the parking or runway so the FDMs could find the surface but i didn't expect the shuttle, started in pause mode, would init at 10000 feet and then drop to the pad... that's wild! hahaha...

plus i only have the pad... not the tower, too... the pad is just off the side of the pavement but so far she's still standing while i hunt for the manual to attempt a quick default launch and at least see if i can get into space :)
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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Re: Shuttle launch problems

Postby Thorsten » Thu Jul 04, 2019 4:06 pm

would init at 10000 feet and then drop to the pad.


It doesn't - it's teleported to the pad a bit later, so the altitude difference doesn't really matter, and 10.000 ft up is high enough such that you can launch from most airports (the scheme fails if you want to launch from any elevation > 10.000 ft)

plus i only have the pad... not the tower, too...


Gantry is optional, you need to select it.
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Re: Shuttle launch problems

Postby wkitty42 » Thu Jul 04, 2019 4:29 pm

right to both... yes, i realized the teleport when i was watching from outside...

unfortunately, i seem to be missing something... i've got the lightweight manual and trying to follow the launch flow on page 37... i've done the lat/long setting for the pad and the 270 heading in the location tab of the launcher... that all looks good... then i've done the part where you deactivate the existing flight, move the slider all the way left to 28 degrees and activate that... then i've followed the steps for the APU startup and gotten all of that going...

seems to be good to go so i shift to an outside view, helicopter view IIRC... hit SHIFT-I to ignite the engines and hope for a good launch... the main engines light for a few seconds and then shut off and that's the end of that attempt... no clue as to why... it has done the same thing 4 or 5 times...

one thing i did figure out is that i need to undo all the APU settings if i want to restart the sim and try again from a cold start otherwise it loads with them still set...

how can i see the mission timer so i can maybe try to do these things on the time schedule? maybe that's where i'm going wrong and hitting SHIFT-I before launch time? i dunno...

i think i'm in that zone known as "doing the same thing over and over expecting something else to happen is crazy" :mrgreen:
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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Re: Shuttle launch problems

Postby Thorsten » Thu Jul 04, 2019 5:09 pm

seems to be good to go so i shift to an outside view, helicopter view IIRC... hit SHIFT-I to ignite the engines and hope for a good launch... the main engines light for a few seconds and then shut off and that's the end of that attempt...


Probably the APU part was not ready..., that causes a launch abort.

Can you post a screenshot of the APU dialog when you think it's good?

one thing i did figure out is that i need to undo all the APU settings if i want to restart the sim and try again from a cold start otherwise it loads with them still set...


That should definitely not be true (and has never been the case for me) - APU settings are not persistent.
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Re: Shuttle launch problems

Postby eatdirt » Thu Jul 04, 2019 6:19 pm

the main engines light for a few seconds and then shut off and that's the end of that attempt.


Best guess, you have forgotten to switch the hydraulic pressure to NORM once the APU are running!? (For the Gantry, yes, I clicked on the option in the menu, by default it is not there as you spotted!)
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Re: Shuttle launch problems

Postby Vinny002 » Thu Jul 04, 2019 7:48 pm

I have the FGAddon space shuttle.
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Re: Shuttle launch problems

Postby wkitty42 » Thu Jul 04, 2019 7:52 pm

Thorsten wrote in Thu Jul 04, 2019 5:09 pm:
seems to be good to go so i shift to an outside view, helicopter view IIRC... hit SHIFT-I to ignite the engines and hope for a good launch... the main engines light for a few seconds and then shut off and that's the end of that attempt...

Probably the APU part was not ready..., that causes a launch abort.

yeah, in further attempts i've noticed that the barber poles go away and as the RPMs come up and pass a certain point, the barber poles come back...

Thorsten wrote in Thu Jul 04, 2019 5:09 pm:Can you post a screenshot of the APU dialog when you think it's good?

yeppers... this one is now with the development branch from the repo... i thought what may have been in FGAddon might have been older and the dev branch might have some fixes...

here's four shots stepping through the APU startup... i'm only doing APU-1 for this...
between 3 & 4 the barber pole came back as RPMs passed some point...
in 5 i turned the pressure selector on which changed the PSI up to 3000...

#2 - just before pressing the [Start/Stop] button
Image

#3 - watching RPM climb
Image

#4 - RPM maxed
Image

#5 - after setting hydraulics to NORM
Image

the same exact thing happens with the craft in FGAddon, too...

Thorsten wrote in Thu Jul 04, 2019 5:09 pm:
one thing i did figure out is that i need to undo all the APU settings if i want to restart the sim and try again from a cold start otherwise it loads with them still set...

That should definitely not be true (and has never been the case for me) - APU settings are not persistent.

i've found that out, too... i looked at the SpaceShuttle-launch.xml file in the aircraft-data directory and saw that... i may have confused several attempts with starting over... it is a heavy beast to get loaded even with my 8-core 4Ghz setup... i know my 8 cores don't matter :)

so i'm in a paused state awaiting further instructions... is turning the hydraulic pumps to NORM timing critical? and when do the hydraulic pumps need to be turned on? step 7 says to turn the pumps to NORM but nothing is ever said about actually turning them on as you can see in my screen shots...

here's the instructions from page 37 of the PDF...
Now do the following (for all three switches of a group,
each controlling one APU):

(1) Switch APU controller power on — this connects the
turbines with power and activates their digital control
unit

(2) Open the fuel valves — this allows hydrazine to flow
from tanks to turbines

(3) Switch the water spray boiler controller power on —
this connects the cooling units to electrical power and
activates their digital controller

(4) Open the boiler N2 valves to allow pressurized nitro-
gen to push cooling water into them

(5) Check the talkback — it should now be grey rather
than stripe-pattern (’barberpole’), indicating that the
APU is ready to start. If the APU is not ready, check
the previous steps and verify that each switch is where
it should be

(6) Put the start switches into start/run position. Look
at the APU MEDS screen and observe how hydraulic
pressure climbs to 690 (pounds per square feet) as the
turbine reaches operating RPM.

(7) Once the turbine has reached full RPM, engage the hy-
draulic pump fully by switching main pump pressure
to ’NORM’. This puts more load onto the turbine (and
hence the turbine won’t start unless the pump is set to
low). Verify on the MEDS display that pressure now
reads around 3000.
"You get more air close to the ground," said Angalo. "I read that in a book. You get lots of air low down, and not much when you go up."
"Why not?" said Gurder.
"Dunno. It's frightened of heights, I guess."
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Re: Shuttle launch problems

Postby Vinny002 » Thu Jul 04, 2019 8:20 pm

Guys, like I said I got the FGAddon space shuttle.
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Re: Shuttle launch problems

Postby Vinny002 » Fri Jul 05, 2019 4:10 am

Question for you, what space shuttle should I get, the FGaddon space shuttle or the other space shuttle? Thanks!

Cheers,
Vincent
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Re: Shuttle launch problems

Postby Thorsten » Fri Jul 05, 2019 5:09 am

in 5 i turned the pressure selector on which changed the PSI up to 3000...


As long as all three show 3000 psi, you should be good.

So, the net thing I'd like to know for sure is that we're really addressing a launchpad abort - there should be a callout, at least if (in simulation options) the 'failure' callout stream is active. This should be on-screen or read out by text-to-speech.

If we have a launchpad abort, that's triggered by this line being not true

Code: Select all
if ((thrust1 > 400000.0) and (thrust2 > 400000.0) and (thrust3 > 400000.0) and (hyd_pressurized == 3))


The last one is

/fdm/jsbsim/systems/apu/number-systems-pressurized

and you can check that. The first (engines) should usually be good by launch sequence control setting their throttle to 1 - so you could check /controls/engines/engine[0]/throttle (and engine[1] and engine[2] of course)

Since I don't own any control HW, I can't check if or how a joystick can potentially interfere - I am guessing it is possible that if the stick transmits a throttle setting of e.g. 0.5 and that overrides what launch sequence sets, engines are throttled back too much for launch - so if the lack of thrust at ignition is the issue, then try unplugging the joystick during launch.

(I guess most others fly with stick, so normally this does not seem to be an issue, but what do I know...)

So, that's the things to check if we have a launchpad abort. If we do not, then it gets more complicated.
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