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Space Shuttle - Bugfixes

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Re: Space Shuttle - Bugfixes

Postby GinGin » Thu Jan 17, 2019 10:07 am

Thanks for that Wayne :)
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Re: Space Shuttle - Bugfixes

Postby GinGin » Thu Jan 17, 2019 11:08 am

Quick question here:

FG version: 2018.1.1
I pulled the last Dev branch.

Launch scenario, APU started.
I got a launch Pad abort every time I try since this morning, MPS don't reach 100% and Launch is automatically aborted.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Thu Jan 17, 2019 12:39 pm

As Gingin said, big thanks Wayne, that is really a huge and I suspect quite unpleasant work you're doing there, that's very much appreciated!
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Thu Jan 17, 2019 12:43 pm

Not sure about the particular combination with 2018.1.1 - I've tested launch with the Shuttle stable against 2018.3.1 which worked fine. I've just tested the latest Shuttle development with an older FG version and it also works fine.

So either there's a regression somewhere in FG or I don't know, but there doesn't seem anything odd on my side.
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Re: Space Shuttle - Bugfixes

Postby GinGin » Thu Jan 17, 2019 2:30 pm

Alright thanks.

First time I encountered that, I will move to the 3.1 and see what happens :)
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Re: Space Shuttle - Bugfixes

Postby wlbragg » Thu Jan 17, 2019 5:33 pm

I got a launch Pad abort every time I try since this morning, MPS don't reach 100% and Launch is automatically aborted.

Interesting, I have had that for awhile in 2018 ??. I figured it was something I was doing wrong although I was following the checklist and all was green.
I just now tried it in my current build, FGFS next of about a couple weeks, 2018.3.2 fgdata. Worked fine!
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Re: Space Shuttle - Bugfixes

Postby GinGin » Mon Jan 21, 2019 1:24 pm

Alright, seems to work now for reasons I don't know, same version :)

@Wayne: I found other flipped around switches, in Ku Antenna Panel
Do you think it is possible to increase the readibility of the text above the switches?

Thanks for you help :)


Image
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Re: Space Shuttle - Bugfixes

Postby wlbragg » Tue Jan 22, 2019 9:16 pm

I pushed the corrections to the normals on A1 and A11. Thanks for spotting them and letting me know.

Do you think it is possible to increase the readibility of the text above the switches?

Yes, i don't recall if that legend was a rip from the 3d view images or from the crew manual. I need to look at the saved art. Personally, I thought those weren't near as bad as others I've been noticing.
There was method to our madness in the origination of those textures, we tried when possible to rip the actual text used on the original panels. Unfortunately there were some angles better then others.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Thu Jan 24, 2019 8:56 am

Hi there,
got some troubles at TAEM after some quite non-standard re-entries. I don't understand what's going on, any help appreciated.

The re-entry itself is wild, but that works. However, as soon as I am reaching TAEM, the Shuttle gets ripped seconds after due to "too high dynamical pressure". I've tried 2 times, same result, even if I manually take control and "pull-up" to slow-down, no joy. On the DPS, I am indeed reading a qbar > 500 as soon as TAEM is announced, but moments before, it seems to be reasonably around 300. See last moments in that timelapse:

4k_reentry_hard_taem.webm

I am super frustrated :)

Edit: Trying a few times more, I saved my "a..." by pulling it hard!!

Thanks,
Cheers.
Last edited by eatdirt on Sun Jan 27, 2019 10:19 pm, edited 1 time in total.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Thu Jan 24, 2019 6:44 pm

qbar comes right from JSBSim, so we have to assume that the value is really reflecting the orbiter state in the atmosphere (there's no possibly fudging I can think of to make that go away).

It can grow fast if you sink fast... and it would be rather unusual to be so close to the limit during entry (we do pitch down at TAEM interface because we won't fly high AoA any more, so that goes along with an increased sinkrate).

Basically you lose control authority and can't pull up because the actuator stalls and can't move the airfoil against the pressure any more.

So I don't think that's a bug, I think your chosen pattern really killed you.
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Thu Jan 24, 2019 7:33 pm

we do pitch down at TAEM interface because we won't fly high AoA any more, so that goes along with an increased sinkrate


Thanks for the explanations, makes sense, we clearly see it in the timelapse. I'll try a more aggressive reentry to loose more energy before TAEM, or switch to White Sands to be more gentle all over!
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Re: Space Shuttle - Bugfixes

Postby GinGin » Fri Jan 25, 2019 7:45 pm

@Thorsten: A quick return on the BPV stuff with ISS target.

Most of the time, I got the BPV inverted as I observed some days ago.

For Earth and Solar tracking, it works as intended.

For ISS ( TGT 1), with BPV 3 ( -Z), Shuttle seems to track ISS with the belly (+Z axis)

Image



Same with BPV 1 ( +X axis), Shuttle tracks ISS with the tail

Image




Another question about the Aft RCS acceleration

I almost never used them before with OPS 202 as we had quite huge velocity.
I tried them with small DV associated with small Lambert corrections.
Do you use them also for Rendez vous?

When I select item 4 to select Aft RCS, timing doesn't seem right and DV is not decreasing when I fire aft RCS

So I decided to test it a bit further, and I think AFT - X RCS have a too slow acceleration

In SCOM, it is said that AFT RCS produce an accel of 0.6 fps²

In game, to add 2 fps with RCS it takes me almost 8 sec ( twice the time)

I don't know if you observed the same thing :)

Thanks for your help
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Sat Jan 26, 2019 2:49 am

Most of the time, I got the BPV inverted as I observed some days ago.


I didn't test excessively but just ran through all three of them, and it seemed to do fine (?)

I even tested changing from +X to -X to see if there was any attitude region in which it'd always align the wrong axis (technically we maximize the dot product of body axis and tracking vector, so this should not happen...), but it did not.

So the next idea would be that there's some geographical region for which this fails - basically once I know the pattern, I can add - signs where needed... I'll poke a bit more.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Sat Jan 26, 2019 3:01 am

In SCOM, it is said that AFT RCS produce an accel of 0.6 fps²


I've hacked in every jet individually from a technical schematic (they're not all the same thrust, some are a few percent weaker), I've double-checked the ISP and propellant use. To my recollection the RCS translation mode fires all available jets, so the only thing to be checked is whether that is actually true - otherwise I can't do anything about the acceleration.

Edit: I've just checked that - firing the RCS for 10 seconds gave me 5.4 ft/s additional velocity and I saw all four backward firing jets go off.

So this seems okay-ish (actual acceleration depends on orbiter weight of course, and using the keyboard it takes a second to ramp to full thrust).
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Sat Jan 26, 2019 5:49 am

Re-checking the tracking axes, I still can't find anything odd (except that DAP-A has the deadbands too tight for the job).
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