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Space Shuttle - Bugfixes

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Re: Space Shuttle - Bugfixes

Postby amalahama » Fri Apr 10, 2020 9:14 pm

Hi! Hope all you are well and safe on these difficult times!

Quick Q, Does FG Shuttle work well in last FG release? (2019.1.1)?
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Sat Apr 11, 2020 5:41 am

Quick A, no, that release is very buggy.
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Re: Space Shuttle - Bugfixes

Postby GinGin » Sat Apr 11, 2020 4:50 pm

wlbragg wrote in Thu Apr 09, 2020 10:58 pm:White separated ET tank done and pushed to development repository.


Perfect, thank you.
Ready for next week STS 1 :)
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Re: Space Shuttle - Bugfixes

Postby amalahama » Sat Apr 11, 2020 4:52 pm

Thorsten wrote in Sat Apr 11, 2020 5:41 am:Quick A, no, that release is very buggy.


Ok downgrading to FG2018 then
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Tue May 12, 2020 7:51 pm

Hi there,
post here a nasty one, around since a while, quite rare but not extraordinarily rare. Doing OMS-2 burn calculations, pressing ITEM+22, leads, sometimes to erroneous results, both on the display and on the console.
An example, PEG-4 for Hubble insertion, I get this:

Code: Select all
1479.85 [ALRT]:nasal      Computing trajectory prediction...
 1479.85 [ALRT]:nasal      Orbital elements:
 1479.85 [ALRT]:nasal      Semimajor axis [km]:  6635.446254506209
 1479.85 [ALRT]:nasal      Eccentricity:         0.04290483958272571
 1479.85 [ALRT]:nasal      Inclination [deg]:    28.35761725236713
 1479.85 [ALRT]:nasal      Lon. asc. node [deg]: -166.2921477943875
 1479.85 [ALRT]:nasal      Arg. of PA [deg]:     69.78973579144555
 1479.85 [ALRT]:nasal      True anomaly:         224.2916020406963
 1479.85 [ALRT]:nasal
 1479.85 [ALRT]:nasal      TA: 293.4410661191535TP: -13.89241886432466


The TP is obviously wrong, I am sure my input are fine. I cancel, ITEM+22, reload calculation ITEM+22 (without touching anything else):

Code: Select all
1501.48 [ALRT]:nasal      Computing trajectory prediction...
 1501.48 [ALRT]:nasal      Orbital elements:
 1501.48 [ALRT]:nasal      Semimajor axis [km]:  6904.548511180907
 1501.48 [ALRT]:nasal      Eccentricity:         0.001991050894581953
 1501.48 [ALRT]:nasal      Inclination [deg]:    28.25628261241097
 1501.48 [ALRT]:nasal      Lon. asc. node [deg]: -166.7602670358378
 1501.48 [ALRT]:nasal      Arg. of PA [deg]:     269.8993128906867
 1501.48 [ALRT]:nasal      True anomaly:         43.09186820085739
 1501.48 [ALRT]:nasal
 1501.48 [ALRT]:nasal      TA: 292.4945649567842TP: 277.5357547429093


Got that with PEG-4 or PEG-7, typically one over ten attempts, when I am looping on the calculations for optimizing (2020.2.0, gc-threaded=false)

cheers,
Chris.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Wed May 13, 2020 5:06 am

Never seen it, sorry.
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Re: Space Shuttle - Bugfixes

Postby GinGin » Wed May 13, 2020 11:05 am

What was the PEG 4 value you inserted ?
What PEG 7 values have been calculated ?

Maybe it does not converge etc

For optimizing, I am using LEO Tool with a lot of iterations, much more than what is allowed in sim ( 30 in the sim and sometimes it takes up to 400 or 500 to find a complex peg 4 solution)
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Re: Space Shuttle - Bugfixes

Postby eatdirt » Wed May 13, 2020 1:51 pm

What was the PEG 4 value you inserted ?
What PEG 7 values have been calculated ?


I used the ones recommended in hst.xml (that was with official devel branch, not yours)
Code: Select all
TIG 000/00:57:40 thetaT 355 H 288 c1 0.0 c2 0.0


The PEG-7 were having quite some components on VZ, but they did work fine when the numbers were rational, I did burn it fine. It looks more to something interfering sometimes with the coordinates, maybe something related to the jumps we see sometimes of ISS etc... If at some point the V becomes huge? Dunno. We should keep an eye on this hoping to get more info.
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Re: Space Shuttle - Bugfixes

Postby GinGin » Wed May 13, 2020 2:05 pm

Yes, but you used the one recommended with a different Orbit Insertion.
Adjust the TIG at Apogee and reduce the theta ( 1 mn less in TIG is 4 ° less in theta roughly)
Delta Vz should be almost null with a good solution. First thing to work on that is to really have a TIG at an apsis , then to play with thetaT
Last edited by Johan G on Tue Jun 30, 2020 2:32 pm, edited 2 times in total.
Reason: Please avoid quoting the entire preceding post.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Wed May 13, 2020 3:02 pm

I used the ones recommended in hst.xml (that was with official devel branch, not yours)


That never worked well unfortunately... so you shouldn't see it as a recommendation at all.
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Re: Space Shuttle - Bugfixes

Postby MrFickles » Mon Jun 29, 2020 2:59 pm

Hi, what is the recommended REI for deorbit? I noticed that when I use 4000nm away from the landing field at EI, the shuttle is severely under energy (the shuttle symbol usually starts halfway down the screen on OPS304) and will end up landing somewhere in mexico.
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Re: Space Shuttle - Bugfixes

Postby Thorsten » Mon Jun 29, 2020 5:40 pm

It actually depends on the flight path angle at EI - if the angle is shallow enough, you can easily do 4000 nm, if not then you land in Mexico. The flight path angle in turn depends on the details of your de-orbit burn - basically you can control it by doing a PEG-4 fit.

So there's no 'one size fits all' answer - if you want a quick solution, the MCC solution which you can request for a circular orbit usually gets you home. If you want to be realistic, you have to do full mission planning and pre-calculate the de-orbit burn with a good flight path angle and REI.
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Re: Space Shuttle - Bugfixes

Postby GinGin » Wed Jul 01, 2020 11:39 am

MrFickles wrote in Mon Jun 29, 2020 2:59 pm:Hi, what is the recommended REI for deorbit? I noticed that when I use 4000nm away from the landing field at EI, the shuttle is severely under energy (the shuttle symbol usually starts halfway down the screen on OPS304) and will end up landing somewhere in mexico.



You can also play with "item 3" in OPS304
It will trigger low energy logic, decreasing the angle of attack to decrease the drag ( up to 10 %)
That has a huge impact on downrange if done early on.


Like emphasized by Thorsten, Flight Path Angle is the parameter to play with for a good entry
I managed Standard Entry around 4500 Nm ish with a proper PEG 4 deorbit solution.

4000 Nm should be easily doable with a good entry angle and a perigee not lower than 20 Nm
LEO tools is almost mandatory for that

http://www.science-and-fiction.org/science/leo_targeting.html


Those PEG 4 parameters are nominals for a deorbit burn 180 ° before the landing site

Code: Select all
thetaT 112.3
H 65.8
c1 15310
c2 -0.6157
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Re: Space Shuttle - Bugfixes

Postby Aomurasaki » Sun Aug 16, 2020 9:24 pm

Hi Thorsten , yo did an amazing job. as usually i'm not really sure if this is the right thread. Here is the deal: the superior and overhead panels are missing.
Image
https://ibb.co/F8grdDh
Image
https://ibb.co/PjThV0N
I just try to "disable point sprites for runway lights" as this topic says http://wiki.flightgear.org/Troubleshoot ... _artifacts but there's no (visible) effect. That's all , hopefully you can attend my post.
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Re: Space Shuttle - Bugfixes

Postby legoboyvdlp » Sun Aug 16, 2020 11:44 pm

Did you enable the detailed cockpit in the settings window?

I'm pretty sure this is contained in the flight manual available at http://www.science-and-fiction.org/ :)
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