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Space Shuttle - Development

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Re: Space Shuttle - Development

Postby Thorsten » Sun Mar 31, 2019 7:30 am

Anychance to have the grey part brighter ?


You can try... I vaguely remember there was an issue with the visibility of the numerals - in the original version they're different color dependent on what part of the sphere they're on, but that's rather difficult to compute (and at that time I was thoroughly fed up with the ADI in any case...)

If you open SpaceShuttle/Nasal/PFD/p_pfd.nas, the lines are

Code: Select all
   p_pfd.adi_sphere_bg = device.ADI.createChild("path")
        .setStrokeLineWidth(1)
   .setColorFill(0.3,0.3,0.3)
   .setTranslation (255, 175)
        .setColor(1,1,1);


and for the on-orbit version

Code: Select all
   p_pfd_orbit.adi_sphere_bg = device.ADI.createChild("path")
        .setStrokeLineWidth(1)
   .setColorFill(0.3,0.3,0.3)
   .setTranslation (255, 175)
        .setColor(1,1,1);


the setColorFill defined the grey - when you change to (1,1,1) you get white. You can play around, and if you find a good combination, we can use that.


That works ok ( like we said one time, atmosphere is a bit higher than expected in FG, with effects that are not calculated by leo up to 80 Nm ish )


It's no problem including drag in principle - it's a numerical scheme after all - but the drag is *very* AoA dependent, and there's really no good way to predict what AoA you'll fly...

Ah yes one thing, ADTA editing in OPS 6 ( contigency) and within MM 602
It doesn't work, need to be in the next mode MM 603 to be able to edit item 25 and 28


Ah, guess I never tried that... always a bit busy during the RTLS. I'll have a look.
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Re: Space Shuttle - Development

Postby Thorsten » Sun Mar 31, 2019 7:56 am

Ah yes one thing, ADTA editing in OPS 6 ( contigency) and within MM 602
It doesn't work, need to be in the next mode MM 603 to be able to edit item 25 and 28


The issue seems to be that the filtering code wants the variables TAEM_guidance_available or TAEM_TACAN_available to be set - because that's when the internal data structures which are needed start being maintained.

Usually you would intercept TACAN before deploying air data probes, so by the time you want to edit air data altitude, TACAN would be good. Dependent on the chosen weather system, you also might want to wait till the weather at the destination has initialized so you can use the correct pressure (which usually would be at TAEM interface).

So I guess trying to do that in MM 602 is simply too early - it would not do anything useful, that's why it doesn't really work.

I played on trajectory loft to lower the MECO altitude ( I am trying around 350 kfeet, less loft )


Set this

Code: Select all
<srb-climbout-ang-bias-deg type="double">0.0</srb-climbout-ang-bias-deg>


to a few deg negative to get faster and lower after SRB-sep. Then set this

Code: Select all
<ballistic-climb-ang-bias-deg type="double">0.0</ballistic-climb-ang-bias-deg>


to a few deg negative to point the Shuttle a bit down while it climbs towards arctop after SRB sep and reaches a lower arctop. Finally, set this to the desired offset negative to have a lower trajectory target at MECO


Code: Select all
<trajectory-loft-ft type="double">0.0</trajectory-loft-ft>


Only the latter parameter will be decisive (guidance will try to move the Shuttle there regardless of what the first two parameters do, it'll just be lots of inefficient up and down if the other two aren't changed)
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Re: Space Shuttle - Development

Postby GinGin » Sun Mar 31, 2019 2:09 pm

Thank you for the exhaustive answer , some stuff to try there with the trajectory shape :)
Indeed , it was going up and down with just the last value offset in feet .
I will try then to go degre by degree associated to 10000 feet .

If I remember well , you said something like a degree of Offset for 7000 to 10000 feet of altitude offset ?


I will play with the color, and see if I come up with something good.

I started to read all the wiki stuff about canvas and how to create mfd.
A lot tougher than what I thought to create a dps page .

I was looking to that for the ascent page ( 102 and 103 )
I had a look in the dps Pictionary , I always mix pass and bfs ascent page .

It seems that the one we have on pass for first stage and second stage is for the bfs ( well displayed on bfs ) and for stage 1 and 2 in pass display it is a melt of rtls and ascent display that is the same for mm102 103 and 601 ( and tal and ato, just the page name change )


The rtls page that come up when rtls is depressed is for the bfs ops 601 .

I wanted to try to modify it. The pass ops 102 103 should look like that.

Image





Yes for the adta édition , it works when tacan was incorporated
But for ecal or some entry without tacan nearby , it should be possible to incorporate adta into gnc as it as to fed data’s before Mach 3 if I remember correctly .
Not a big deal anyway , for a normal entry with tacan available , it works and for rtls or contingency . It works in mm 603.

Will do some more tests on that also :)
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Re: Space Shuttle - Development

Postby Thorsten » Sun Mar 31, 2019 2:52 pm

I wanted to try to modify it. The pass ops 102 103 should look like that.


Actually the pages are a mixture of SVG elements which are switched on and off by the code and procedurally generated elements - so there's no one place where you can edit it.

I'm not sure what exactly you want to change (I had the impression we're pretty close to the real 102 and 103) - the way the DPS Dictionary describes the page is a bit weird, because it contains this mash-up of all the nominal and abort variants - can you elaborate?

But for ecal or some entry without tacan nearby , it should be possible to incorporate adta into gnc as it as to fed data’s before Mach 3 if I remember correctly .
Not a big deal anyway , for a normal entry with tacan available , it works and for rtls or contingency . It works in mm 603.


It should conceptually be possible, but the way we process it is that the area nav set class manages errors and sensor data filtering - and that class requires either a TACAN or a TAEM guidance flag to be initialized.

If you have an abort to some airport where no TAEM guidance is available, we never initialize the corresponding class, which is why we can't do any filtering.

So making this work is not a small thing unfortunately, it'd require a major re-factoring of the area nav code to pull air data out of the class.
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Re: Space Shuttle - Development

Postby GinGin » Sun Mar 31, 2019 4:06 pm

it contains this mash-up of all the nominal and abort variants - can you elaborate?


Yes, sure.
Mash up, I had the same feeling.

I fired up a few days ago SSMS 2007, I had a DPS page for ascent in my head , that one :

Image


Then I realized we didn't have it and asked myself from where it was coming.
I Had then a look into the DPS pictionnary.



So it seems that actually, all our DPS pages (102, 103 , 601) are good, but for the BFS ( and we are missing that mash up page for Pass 102/103/601 ATO and TAL)

Indeed, here BFS for first stage (MM 102) (page 5.8

Image



Then the BFS second stage ( MM 103) (page 5.9)

Image



Here the BFS page when we call up an RTLS or conitgency abort ( MM601)

Image

We have all of the above.




BUT the PASS actually display that one for both MM 102 , 103 ( just title change) and also for OPS 6 and ATO/TAL ( where just the title change)
It is a mash up of nominal ascent and aborted one ( which is, I agree, less clear than the BFS one) (Page 3.4)
But it is apparently like that for all the Operationnal Increment ( ALL at the bottom right of the page)

Image



From my understanding, the red line is first stage, then blue one for RTLS window ( early second stage up to Vrel 8 kftish) and purple one for the GO ( ATO window opening uphill) and then the rest of stage 2 is displayed on the BFS mm 103

Image


Don't know what do you think about it?








that class requires either a TACAN or a TAEM guidance flag to be initialized.


Ah alright, I understand what happened then.
If no Tacan, that is why incorporation is possible in mm 603 with the TAEM flag initialized, thanks.



So making this work is not a small thing unfortunately, it'd require a major re-factoring of the area nav code to pull air data out of the class.


Yes, no worries.
It is really a particuliar case, and ADTA are usually taken into GNC around M 2 with MM 603, so no major break out
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Re: Space Shuttle - Development

Postby Thorsten » Sun Mar 31, 2019 4:48 pm

BUT the PASS actually display that one for both MM 102 , 103 ( just title change) and also for OPS 6 and ATO/TAL ( where just the title change)


SCOM on page 7.1-1 shows explicitly PASS ASCENT TRAJ 1 and 2 (and BFS ASCENT TRAJ 2 on 7.1-2) , and they don't have the RTLS trajectory on them. As I said, the DPS Dictionary is rather confusing about what is visible where and SSMS 2007 probably didn't do the research.
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Re: Space Shuttle - Development

Postby GinGin » Sun Mar 31, 2019 5:17 pm

Yes, that is confusing.
SCOM from 2008 is for OI 33


I was looking to this DPS

https://www.nasa.gov/centers/johnson/pdf/359895main_DPS_G_K_7.pdf
Revision K up to OI 30 June 2004
They might have changed that from OI 30 to 33



I will try to find a more up to date dictionnary


By the way did you have a look on SCOM page 1151 talking about the Spec 54 ascent for lateral guidance for abort ( one of the last update to the SHuttle program)
Just discovered it, they did so many changes to the GPC in the last 10 years of Shuttle life.



But yes, for the last GPC revision, you are right, like on that video
So the mash up Pass display was for OI 30 and before 2004 apparently

https://www.youtube.com/watch?v=7NvKjtqhvlA

I just noticed also in the video that before main engine ignition, the PFD parameters are Red with no values for speed alt acceleration etc



Edit: Found that link

https://www.nasaspaceflight.com/2007/10/shuttle-discoverys-new-software-from-oi-32-to-windows-xp/


Enhanced crew situational awareness: Added phase tailored PASS 6X Traj Displays. Creates first stage, second stage, and RTLS trajectory displays similar to BFS to replace the current PASS 6X Traj display. Provides a PASS capability to assess trajectory performance throughout the ascent powered flight phases.


So the update that changed the Pass and BFS for ascent into the same batch of soft are the OI 32 in 2008
And before that, there was the mash up ascent pass stuff :)
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Re: Space Shuttle - Development

Postby Thorsten » Sun Mar 31, 2019 5:45 pm

So the update that changed the Pass and BFS for ascent into the same batch of soft are the OI 32 in 2008


Interesting - I never realized...

I suspect with all the GPS capabilities added, we're generally flying a rather late vehicle... I guess I've usually used SCOM in case of conflicting info.
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Re: Space Shuttle - Development

Postby GinGin » Sun Mar 31, 2019 6:02 pm

Interesting - I never realized...


Same, took me time.

I started to see some differences between GPC udpate when we talked about IMU page.
I told you that there was some differences on the spec 21 compared to what I have read, but you coded one type of Spec 21 page and I was looking to an update of it.
( Minor though, I don't even remember, I think that with the new OI, it was possible to use the Star Tracker align for either a torque or a matrix, and just torque with previous soft ie. no difference in game)

But yes, Shuttle you coded as the latest tools, also for the PFD and all that stuff, so good :)
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Re: Space Shuttle - Development

Postby Thorsten » Mon Apr 01, 2019 5:51 am

Yeah, also the SPEC 33 has different incarnations - we have the one with lots of GPS info on it, the RNDZ workbook describes a pre-GPS one.

I guess if there's interest in that kind of thing and someone takes the trouble of documenting what is what phase, we could implement different selectable software versions.

Things get more messy when the HW actually changes, panel layout is more difficult to change. The pre-glass cockpit Shuttle would require some serious modeling effort...
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Re: Space Shuttle - Development

Postby Thorsten » Mon Apr 01, 2019 10:34 am

... and after a successful single engine TAL to LeTube, the stable milestone 11 is now tagged.
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Re: Space Shuttle - Development

Postby GinGin » Mon Apr 01, 2019 11:01 am

Very nice .

I made a couple of tal to zza and istres.
Perfect one, and now even the dump after meco is supported with oms tvc working

Single engine tal after 14 kfts is also good.


Speaking of entry , I noticed that the Dref is with a minus sign instead of positive one ( it was positive in previous version , I checked the screen )

Also , I did some screens with superposition of the real entry page with all the drag lines. And I found that is really well correlated with the actual entry path ( a tad to the left )
Especially for entry traj 2 to 5, the dref is in accordance with the drag hard lines
It can be a good addition may be.

I will post later the superposed screens if you are interested
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Re: Space Shuttle - Development

Postby legoboyvdlp » Mon Apr 01, 2019 3:39 pm

At the 60 metre range the propellant dump seems odd:
Image
Image

At this angle its normal.
Image

At 140 metres it seems fine.

Also, is the aircraft meant to feel "bouncy" as it goes past mach 22 or so? I realize the forces were quite high but it did seem to have some phugoid in the pitch axis.


Also, is yaw offset by 90 degrees here? This is in Aerojet with AUTO...

Image
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Re: Space Shuttle - Development

Postby legoboyvdlp » Mon Apr 01, 2019 4:09 pm

And here we are after a rather dicy landing:
Image

I didn't get an opportunity to try it before but now that I have, I do find the Ctrl + V shortcut slightly annoying when i want to jump back to the cockpit - especially since it takes keyboard control (ie you can't use the 5 key to center controls).
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Re: Space Shuttle - Development

Postby wlbragg » Mon Apr 01, 2019 8:27 pm

I'd say that was a very dicey re-entry as well. :lol: Looking at the condition of the fuselage you were at the upper limits of re-entry heat management.
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