## Space Shuttle - Development

Discussion about development and usage of spacecraft

### Re: Space Shuttle - Development

Sorry, I don't remember offhand. I know we did this at some point, but I'm not sure what the precise implementation was.
Thorsten

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### Re: Space Shuttle - Development

Alright, no worries.
I remember we tweaked it for ascent.

Well, I am pretty sure we have inertial speed for entry. So easy enough to compare it with Entry Cue card in Earth relative speed ( Normally, in OPS 304 speed tape switch to Vr)
GinGin

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### Re: Space Shuttle - Development

Hi there,
I have just made the most improbable launch ever thanks to my 8 months old daughter who randomly managed to press CTRL+I and put the joystick thruster to maximum.

The net effect is to perform an ascent with SRB + OMS thruster and no hydraulics... Well, we *survived* qbarmax and went up in straight line, then down to our fate after booster extinction

Just one thing, I did not succeed to separate the SRB manually, so no chance at all, do we need the APU for this?

LoL!
eatdirt

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### Re: Space Shuttle - Development

I'm not sure how you managed to ignite SRBs without hydraulics - never worked for me, the ignition command checks whether main engines are > 90% of thrust, if that's not the case you get a launchpad abort.

Anyway, I've just checked, separation mode to MAN and depressing separation button works fine for me. The results are catastrophic of course...
Thorsten

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### Re: Space Shuttle - Development

Ok, I have been able to reproduce!! In fact, my daughter certainly touched only the "throttle" control on the joystick, it is a wheel "axis 2" in the joystick configuration, and it is configured to "all throttles".
If you turn throttle on, with joystick, it ignites OMS engines and also the SRB. With keyboard only nothing happens, so it looks like a bug with joystick only then.
Afterwards, the SRB separation switch does nothing, tried even after switching APU on during ascent... Trying to SEP the external tank complains about the SRB still be around.

I know, this is quite off-nominal situation, and you need to have a 8-month old brain to try this

Cheers,
Chris.
Last edited by eatdirt on Sun Apr 07, 2019 9:49 pm, edited 1 time in total.
eatdirt

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### Re: Space Shuttle - Development

Ahah amazing
A new tester in the pool
GinGin

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### Re: Space Shuttle - Development

If you turn throttle on, with joystick, it ignites OMS engines and also the SRB. With keyboard only nothing happens, so it looks like a bug with joystick only then.

I can't test this (I don't own a joystick) - but presumably the joystick config somehow overwrites the Shuttle settings that determine which engines are linked to the throttle input command (?)

]Afterwards, the SRB separation switch does nothing, tried even after switching APU on during ascent...

It may be the case that by dialing throttles directly there never was an ignition command and sequence (you'd still be in MM 101 during ascent) - in that case, many commands would just not be parsed because the corresponding mission stage management loop isn't running.

But just to make sure - the switch is quite a complicated beast, it requires you to first set mode to MAN, then open the cover and then press the button (we wouldn't want to do this accidentially...)
Thorsten

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### Re: Space Shuttle - Development

you'd still be in MM 101 during ascent

You completely right, this is what happens, although manually moving to MM 102 does not help, seems that other initialization steps are skipped in the process. Tried SRB separation in normal launch, works fine indeed, so I guess I am doing the right sequence of buttons press. Anyway, that's such a improbable case, let's forget about it, just need to pay attention that the wheel throttle is not at maximum.
eatdirt

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### Re: Space Shuttle - Development

Being more cautious, looking at BFS syssum1, I see two lines of ullage pressure LH2, is this the case, two measurements in different places, or could it be that one of them being instead LO2?

Cheers,
Chris.

Edit: remove me screwing up launching guidance.
eatdirt

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### Re: Space Shuttle - Development

Here comes the noob question... Got the deluxe manual under my eyes, but I have no idea how to switch on the "Rendez-vous Planner". It displays the shuttle at the origin and that's it, with a bunch of zeros in x, y,z. I can see alpha=16 degrees, but a rate which does not make sense \dot{alpha}=233deg/min (degrees per minute?)

The traj. map shows that I am on something close to ISS in terms of plane inclination and angle, maybe 15 degrees behind, indeed, my post-MECO orbit is about HA=158 HP=72, and I am still in OPS 104.

The console is spitting some error messages though:

Code: Select all
Lambert manager: Another computation is in progress!Lambert manager: Another computation is in progress!New scale set to 500Nasal runtime error: No such member: get_inertial_speed  at /home/chris/.fgfs/Aircraft/org.flightgear.fgaddon.stable_2018/Aircraft/SpaceShuttle/Nasal/canvas/cdlg_rendezvous.nas, line 507  called from: /home/chris/.fgfs/Aircraft/org.flightgear.fgaddon.stable_2018/Aircraft/SpaceShuttle/Nasal/canvas/cdlg_rendezvous.nas, line 389  called from: /home/chris/.fgfs/Aircraft/org.flightgear.fgaddon.stable_2018/Aircraft/SpaceShuttle/Nasal/canvas/cdlg_rendezvous.nas, line 222  called from: /sim/bindings/menu/binding[296], line 1Lambert manager: Another computation is in progress!

Any help welcome!
eatdirt

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### Re: Space Shuttle - Development

Ah - wrong FG core version (or at least FGData).

You're using 2018.3, but the API needed by the orbital target code is part of 2019.1 RC only (the manual actually says so). The dialog can't get the info it needs from the target, so it crashes.

You can get by without a full install by acquiring FGData/Nasal/orbital_target.nas from the FGData repository.
Thorsten

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### Re: Space Shuttle - Development

Thanks, ok, I am not so ridiculous then
eatdirt

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### Re: Space Shuttle - Development

eatdirt wrote in Mon Apr 08, 2019 5:36 pm:Being more cautious, looking at BFS syssum1, I see two lines of ullage pressure LH2, is this the case, two measurements in different places, or could it be that one of them being instead LO2?

in your image, i see two places showing

Code: Select all
LH2   36LO2   76

center screen in image, bottom right corner "MANF P"
left screen in image, bottom right corner "ENG MANF"

what am i not seeing?
"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."

wkitty42

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### Re: Space Shuttle - Development

Bottom left, ULL P LH2

legoboyvdlp

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### Re: Space Shuttle - Development

Well spotted Eat Dirt, should be LO2 .
Wow, I just realized that all the page was filled with parameters that are fed by real input data. So nice
If I remember well, at srb sep, you can see the ullage pressure having a peak with changes in G

Eatdirt: the file you want is this one

https://sourceforge.net/p/flightgear/fgdata/ci/next/tree/Nasal/orbital_target.nas?format=raw

I had the exact same problem, Thorsten helped me also:)

I think we have to move with the dev version of fg also, might be easier
GinGin

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