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Space Shuttle - Bugfixes

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Re: Space Shuttle - Bugfixes

Postby amalahama » Mon Aug 26, 2019 12:04 pm

GinGin wrote in Tue Aug 20, 2019 4:49 pm:2)HAC Size in Spec 50


I think that the closer we are from the HAC , the bigger it is ( like a zoom in stuff)
Here from SSMS 2007 ( same in SSU)

Image


Image


And a real one

Image



Hi, last time I checked this one, I think the problem is that, in Orbiter SSU and also in the real shuttle the HAC circle radius is computed in real time depending on shuttle's height (basically cutting the HAC cone) but for some reason in FG Shuttle it looked like it's static (e.g. HAC is a cylinder, not a cone). I don't know if this behavior has changed since then, however.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Mon Aug 26, 2019 12:16 pm

Hi, last time I checked this one, I think the problem is that, in Orbiter SSU and also in the real shuttle the HAC circle radius is computed in real time depending on shuttle's height (basically cutting the HAC cone) but for some reason in FG Shuttle it looked like it's static (e.g. HAC is a cylinder, not a cone).


GinGin's screenies show indeed some zooming going on because the leg to touchdown point also changes size - and I've explained to you before that there's no strange reason involved - the implemented guidance actually flies the Shuttle around a constant radius and the display shows this.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Sat Aug 31, 2019 6:56 am

However, with interconnection, we should have 200 s ish, and we have a much smaller time ( 110 seconds, confirmed with many tests)


I can't answer that - the RCS thruster characteristics are well known, their ISP and thrust determine their propellant consumption - so it's quite out of the question that we for some reason use multiple times the fuel they'd nominally use.

The only possibility would be if we fire thrusters for dump which in reality would not be fired - but the workbook claims we'd fire all 24 ARCS jets.

If we do that, I can burn all prop in 135 sec.

I think that the closer we are from the HAC , the bigger it is ( like a zoom in stuff)


Lacking any documentation on how the scaling is actually done, at least qualitatively this now happens.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Sun Sep 01, 2019 7:44 am

I can't answer that - the RCS thruster characteristics are well known, their ISP and thrust determine their propellant consumption - so it's quite out of the question that we for some reason use multiple times the fuel they'd nominally use.


Okay, found it - the crossfeed logic double-counts in case you feed from multiple sources - which explains why the fuel can burn so fast.
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Re: Space Shuttle - Bugfixes

Postby GinGin » Mon Sep 02, 2019 8:37 am

Ok, perfect.
Thanks for having a look at all that

So time was halved ? Then it makes sense and it is close to real numbers when it is times 2


Nice new typo

Image


Lacking any documentation on how the scaling is actually done, at least qualitatively this now happens.


I saw that, perfect.
Didn't find any infos on that in workbook, handbook or what ever.
One line in the dictionnary, not real clear.

I think it is just a visual help, to see better while closing in to the runway, and not linked to any shrinking HAC ( better situational awareness )
As the radius decreases with altitude and speed, it should be the opposite way ( Circle would decrease) if it was based on HAC radius variations

I saw your zoom in effect, looks perfect for me.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Mon Sep 02, 2019 9:56 am

This crossfeed issue is more messy than I anticipated - I believe operationally (pressure differences etc) one would only connect one feeding source to the crossfeed manifold and when that is empty, simply switch over.

However, in practice the user may still switch the damn valves however he pleases, so there's quite a lot of combinations we need to support - especially with the OMS Kit into the fray.

There's now three possibiities to arrange a single feeder, three to arrange two feeders and one to arrange three feeders.

And of course, the RCS can be differenciated between the 12 and the 345 manifold isolation valves - something that doubles the number of possible combinations.

The fact that we can decide to only put left or right RCS to the crossfeed manifold doubles the number of combinations yet again.

So my count is now at 28 different OMS to RCS crossfeeding combinations.

This sucks.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Mon Sep 02, 2019 4:00 pm

Hi there,
a lot of new shinny things since I was away, thank you all!

I am coming back to this issue I had a while ago, still have it:

I've just encountered a very weird sound issue with latest fg-next branch snapshot and latest shuttle. I am loosing the cockpit sound of the SSME just before SRB separation, but only the SSME sound. All other sounds in the cockpit are fine, announcements, clicks on buttons. Later on, I also do not hear the external tank separation sound neither. I'll report the problem on the dev-list, but let me know if you think it is a stupid mistake from my side.


I am pretty sure now it comes from OpenAL, I have it with 2018.3.2 as well when I am compiling it against the latest openal-1.19.1 provided by my distro. Moreover I've spotted these error messages, just at the time the SSME sound disappears:

AL lib: (EE) ALCplaybackAlsa_mixerProc: mmap commit error: Broken pipe
AL lib: (EE) ALCplaybackAlsa_mixerProc: mmap commit error: Broken pipe


I am going to submit a bug report to those openAL folks, but if someone has any ideas how to give more information that would be nice, I am only getting the sound issue with the Shuttle and not the other planes, which makes it hard to reproduce for them I guess!

Thanks,
Cheers,
Chris.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Mon Sep 02, 2019 5:42 pm

No idea, sorry - sound really isn't my area of expertise.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Mon Sep 02, 2019 7:23 pm

No pb, I have opened a bug report on openal, here it is if someone else gets the trouble or has some ideas:

https://github.com/kcat/openal-soft/issues/337
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Sun Sep 08, 2019 10:35 pm

Hi there,
I am just running latest fgspaceshuttle snaphost with 2019.1.2, I have issues with the Lambert Targetting after a save/resume, I just cannot make it converge and the numbers displayed in SPEC 34 look crazy. Here a snapshot to summarize:

Image

In SPEC 33, see the \dot{R} which reads NaN :(
In SPEC34, compared to the RDV window, I cannot believe that DeltaX/DNRNG = 50000 kft at TIG1, at the time of the snapshot (MET is around 5h32). It should be more around 300 kft. The relative speed at TIG1 is also impossible, -45000 ft/s ?

All the others windows, RDV, trajectory map, show Hubble just in front of the SpaceShuttle, but it looks like within the DPS, HST target is not properly initialized. Oh, but I may be turning around Earth in the wrong direction??? :)

Any help appreciated!!! Thanks!

Cheers,
Chris.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Mon Sep 09, 2019 6:26 am

It's really hard to see... something seems off, but it is not clear what that something is.

SPEC 33 and the rendezvous window are consistent (the NaN probably is a glitch of sort, note that alpha-dot is also not shown properly).

In SPEC 34, what would help is to change TIG1 to 'essentially now' to see whether it reproduces current ranges or not.

I thought GinGin had tested rendezvous with save/resume? At least last time I tried to resume an old state, it also worked fine for me.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Mon Sep 09, 2019 7:13 am

Thanks for the answer Thorsten, here a snapshot for a TIG1 which is 2 minutes in the future, it is about the same, it looks like there is some huge offset along the X-axis.

Image

In the console, nothing looks bad, Lambert never converges though, which is some kind of expected with these numbers. Only one thing, there is a recurrent message:

Lambert manager: Another computation is in progress!


while I am sure to have ITEM 28 EXEC only once.

PS: I have also tried a resume starting with --aircraft=SpaceShuttle-launch (instead of -orbit), no change for Lambert targetting, but with --launch the \dot{R}=Nan disappears
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Mon Sep 09, 2019 7:18 am

The Lambert manager also handles the node crossing prediction - to avoid having overlapping computations with weird output, the computation ought to be inaccessible while the other process runs.

So it either means your process is running and node crossing prediction tries to get computing time (more likely) or your process never runs and node crossing is computing all the time (less likely).
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Mon Sep 09, 2019 9:26 am

Okay, I've just tried starting with --mission, loading a state that I had saved earlier and applying targeting from there - I got a converging solution and burning it actually got me within 200 m of ISS (I did get to see GinGin's bug with the 3d model not shown and an error message, but I'm not sure how the problem can arise yet...)

So... I'm rapidly hitting a dead end since I can't reproduce the failing targeting.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Mon Sep 09, 2019 12:02 pm

Thanks Thorsten, I am depressed :-/

Would you mind to write explicitly the command you typed for starting the fgfs instance used when you did resume the previous state? At least I could check that the exact same command does not work!

Cheers,
Chris.
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