Board index FlightGear Development Spaceflight

Shuttle launch problems

Discussion about development and usage of spacecraft

Re: Shuttle launch problems

Postby GinGin » Fri Jul 05, 2019 9:21 am

That is a good hint.
I had once your problem Wiktty.
It was due to my slider joy being assigned to the thrust that bypass everything like said EaTdirt and Thorsten .

If you have a joy connected , be sure to deassign thrust from axis
GinGin
 
Posts: 648
Joined: Wed Jul 05, 2017 10:41 am
Location: Paris
Callsign: Gingin

Re: Shuttle launch problems

Postby GinGin » Fri Jul 05, 2019 9:25 am

Same for Vinny, do you have a joystick connected ?
GinGin
 
Posts: 648
Joined: Wed Jul 05, 2017 10:41 am
Location: Paris
Callsign: Gingin

Re: Shuttle launch problems

Postby Vinny002 » Fri Jul 05, 2019 9:39 am

I disconnected the joystick, I loaded up shuttle launch, same issue, then I loaded up shuttle launch, i went to joystick options in-game, assigned all the controllers such as the rudder controls throttle, and many more to none, I exited FG, I loaded up shuttle launch the 3rd time and bingo, the space shuttle is in the vertical position!!!


Cheers,
Vincent
Vinny002
 
Posts: 43
Joined: Mon Jul 01, 2019 8:55 pm

Re: Shuttle launch problems

Postby eatdirt » Fri Jul 05, 2019 12:03 pm

such as the rudder controls throttle


it looks like some other hardware was controlling the throttle then, very good you found it out, and thanks for reporting. Enjoy the shaky ride now :)
eatdirt
 
Posts: 328
Joined: Wed Aug 15, 2018 2:06 pm

Re: Shuttle launch problems

Postby legoboyvdlp » Fri Jul 05, 2019 12:15 pm

Vinny002 wrote in 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?


Definitely the fgaddon one - any other download (especially FGMEMBERS) would not be supported and as I recall the FGMEMBERS one is outdated and broken, anyway ;)

You can also get it from flightgear.org or directly in the launcher.



Glad to hear you got it working - enjoy!
User avatar
legoboyvdlp
 
Posts: 6849
Joined: Sat Jul 26, 2014 1:28 am
Callsign: YV-LEGO
Version: 2018.3.1
OS: Windows 10 HP

Re: Shuttle launch problems

Postby wkitty42 » Fri Jul 05, 2019 2:29 pm

Thorsten wrote in 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.

ok but did you miss this part?
between 3 & 4 the barber pole came back as RPMs passed some point...

i don't know why the barber pole would come back...

Thorsten wrote in Fri Jul 05, 2019 5:09 am: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.

i do not recall anything being displayed on the screen when in the external view watching the SMEs firing up for the few seconds they do before they shut back down... nothing is being spoken by the TTS system either... remember, too, that the above quote is just single APU and no launch was attempted... that barber pole returning when the RPMs go over 50000 or so is what bothers me... i don't think i'll have enough horsepower to record a video with OBS with the shuttle eating so many FPS... otherwise i'd do that and post up a short video showing the problem as it occurs...

Thorsten wrote in Fri Jul 05, 2019 5:09 am: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)

i will check those properties... i do have a joystick with a throttle in place but i generally do not use the throttle... it is a rather short and touchy slider... i've not had problems with not using it and while using other throttle control mechanisms before... now, if i do move the one on the stick, sure there are problems but it is set to zero and stays there with no drift...

Thorsten wrote in Fri Jul 05, 2019 5:09 am: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.

i'll certainly check those properties... it may not help that i'm getting >5FPS, too... i'm guessing maybe my GT730 is a little too slow with its buss... memory usage and PCIe buss usage are well within limits according to the NVIDIA control tool when i look at it while the shuttle is loaded in FG... i need to reboot and unload some things and test again anyway...
"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."
User avatar
wkitty42
 
Posts: 5502
Joined: Fri Feb 20, 2015 3:46 pm
Location: central NC, USA
Callsign: wk42
Version: git next
OS: Kubuntu 14.04.5

Re: Shuttle launch problems

Postby wkitty42 » Fri Jul 05, 2019 2:37 pm

GinGin wrote in Fri Jul 05, 2019 9:21 am:That is a good hint.
I had once your problem Wiktty.
It was due to my slider joy being assigned to the thrust that bypass everything like said EaTdirt and Thorsten .

If you have a joy connected , be sure to deassign thrust from axis

that's interesting... i've never had it interfere with the throttle on any other craft... i'll give it a looksee in a few minutes...
"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."
User avatar
wkitty42
 
Posts: 5502
Joined: Fri Feb 20, 2015 3:46 pm
Location: central NC, USA
Callsign: wk42
Version: git next
OS: Kubuntu 14.04.5

Re: Shuttle launch problems

Postby Thorsten » Fri Jul 05, 2019 3:11 pm

ok but did you miss this part?


No - what you observe is expected (you can read the details in the Shuttle Crew Operations Manual) - in short the presence/absence of the barberpole is a 'ready to start' signal - which goes away when you actually start.

it may not help that i'm getting >5FPS, too...


I can launch fine at 5 fps though, that I have tested.
Thorsten
 
Posts: 10693
Joined: Mon Nov 02, 2009 8:33 am

Re: Shuttle launch problems

Postby wkitty42 » Fri Jul 05, 2019 3:59 pm

on the barber pole: oh! ok... i thought it was supposed to stay away...
i've tried to read the SCOM but either get dents in my forehead from the keyboard or my eyes glaze over and i loose my sight :( i'll keep trying, though...
on running with >5FPS: ok... i'll keep trying...

what i've done so far:
1. in joystick controls, set throttle to [NONE]
2. i only have one joystick, no controllers
3. the only other USB stuff is my keyboard and mouse
4. i'm SHIFT-CLICK on the throttle property in each of engine[1/2/3] to display them on the screen
5. engines 1 and 2 do show 1 after hitting SHIFT-I but engine 3 never moves from 0
"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."
User avatar
wkitty42
 
Posts: 5502
Joined: Fri Feb 20, 2015 3:46 pm
Location: central NC, USA
Callsign: wk42
Version: git next
OS: Kubuntu 14.04.5

Re: Shuttle launch problems

Postby wkitty42 » Fri Jul 05, 2019 4:13 pm

is there a way to restart the simulation after an abort without having to exit and reload the sim completely? these 5+ minute waits for everything to load are painful :(

i'm trying now without my joystick attached because nothing else seems to be working... i get the same exact scenario... everything is good, great RPMs, good hydraulic pressure, SHIFT-I and you hear/see SMEs for maybe 1 or 2 seconds and then they're off... my last test did show three systems pressurized and still throttles 1 and 2 to 1 but 3 stayed 0...
will post new results without joystick connected in about 10 minutes...
"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."
User avatar
wkitty42
 
Posts: 5502
Joined: Fri Feb 20, 2015 3:46 pm
Location: central NC, USA
Callsign: wk42
Version: git next
OS: Kubuntu 14.04.5

Re: Shuttle launch problems

Postby wkitty42 » Fri Jul 05, 2019 4:24 pm

with no joystick or controller of any kind attached... here's a screen shot after i've hit SHIFT-I to launch... this is seconds after the SMEs have cut back off and we've never left the pad...

Image
"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."
User avatar
wkitty42
 
Posts: 5502
Joined: Fri Feb 20, 2015 3:46 pm
Location: central NC, USA
Callsign: wk42
Version: git next
OS: Kubuntu 14.04.5

Re: Shuttle launch problems

Postby Thorsten » Fri Jul 05, 2019 4:59 pm

I wish I could /read/ anything on that screenshot...

Edit - my bad, I can see it larger when I copy/paste the address.

Okay, hydraulic pressure is okay, so is the throttle setting - so the next question would be - what is the peak thrust of the main engines?

/engines/engine[0]/thrust_lb
/engines/engine[1]/thrust_lb
/engines/engine[2]/thrust_lb

(Note that engines are switched off if the launch fails, so a screenshot after the fact is not useful. Also please monitor

/fdm/jsbsim/systems/mps/engine[0]/run-cmd
/fdm/jsbsim/systems/mps/engine[1]/run-cmd
/fdm/jsbsim/systems/mps/engine[2]/run-cmd)


(We're way in uncharted territories here... so I am just starting to rule out possibilities...)

Edit2: And just to be sure - you don't have fuel-freeze or something enabled that would interfere with the fuel flow simulation? You don't set any fuel levels per commandline or so, tanks are all full?
Thorsten
 
Posts: 10693
Joined: Mon Nov 02, 2009 8:33 am

Re: Shuttle launch problems

Postby wkitty42 » Fri Jul 05, 2019 6:44 pm

i'll check those but ummmm, yes, i do have fuel freeze enabled... AFAIK that doesn't inhibit flow numbers in any other craft... it just prevents the tanks from emptying... oh! hummmmm... you might be on to something, though...

if --enable-fuel-freeze is the culprit, because the tank weight doesn't lessen, maybe there could be a red warning telling to turn it off and provide a way to do so? i know you don't want to flip it off automatically... if it is the problem, i'll create myself another .rc (eg: shuttle.rc) file to use with shuttle flights that will explicitly --disable-fuel-freeze... but i'm sure i'm not the only one using it so having a way to turn it off in-sim would be a GoodThing<tm> so we don't have to wait through another 5+ minute load time ;)

i'll have to test it later, though... it is hot here today and my system is currently running at 100+F while basically idle (doing its normal chores)... i'll try to test it this evening once it cools down... hopefully before midnight UTC (2000 my time)...
"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."
User avatar
wkitty42
 
Posts: 5502
Joined: Fri Feb 20, 2015 3:46 pm
Location: central NC, USA
Callsign: wk42
Version: git next
OS: Kubuntu 14.04.5

Re: Shuttle launch problems

Postby Thorsten » Sat Jul 06, 2019 5:16 am

yes, i do have fuel freeze enabled... AFAIK that doesn't inhibit flow numbers in any other craft...


Most other craft don't have such a detailed custom fuel system - the way it's written, fuel-freeze prevents fuel from reaching the engines because the fuel at the engines is the fuel that's missing from the tanks, and if nothing is missing from the tanks, the system concludes that nothing reaches the engines.

In any way, you can't bring a rocket into space without emptying the tank, because the acceleration the main engines provides is laughably insufficient - it can't even keep the Shuttle up against gravity with the ET full - so fuel freeze is absolutely not an option for spacecraft.
Thorsten
 
Posts: 10693
Joined: Mon Nov 02, 2009 8:33 am

Re: Shuttle launch problems

Postby wkitty42 » Sat Jul 06, 2019 3:14 pm

yes and it makes perfect sense once i thought about it and realized that the tanks wouldn't empty... in my case, --enable-fuel-freeze was the culprit... i copied my .rc file to a new shuttle related name, switched to --disable-fuel-freeze, and got a good launch, SRB separation, and main tank separation... then i just left it to drift around the world for a while until i had to leave so i shut it all down because i was going to be gone for several hours...
"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."
User avatar
wkitty42
 
Posts: 5502
Joined: Fri Feb 20, 2015 3:46 pm
Location: central NC, USA
Callsign: wk42
Version: git next
OS: Kubuntu 14.04.5

PreviousNext

Return to Spaceflight

Who is online

Users browsing this forum: No registered users and 1 guest