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Re: Space Shuttle

Postby GinGin » Wed Nov 07, 2018 8:59 am

@wlbraggthat would be just awesome wow.
Was thinking of adding more satelitte for mission, but need to learn the 3 D.
What tools do you use for,that ?

I will chec the docs about it :)
Also, there are pretty good bunch of Hubble in Orbiter mod. I will link you some pictures of what they modelized if you want :)

Servicing Hubble :))))) so cool

I am like a kid at Christmas now ahah
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Re: Space Shuttle

Postby Thorsten » Wed Nov 07, 2018 10:16 am

Need to think of a new hypothesis...


I think I found it - wrong branch of the angle picked by an acos, feeding into a sine later would reverse the sign - the bug would be apparent after exactly 12 hours and heal itself after another 12 hours.

I would say no because if I understand correctly the wiki, playing with simulation rate is just increasing calculation rate of the whole world.


Except of the parts of the world which are not sped-up for whatever reason...
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Re: Space Shuttle

Postby GinGin » Wed Nov 07, 2018 10:22 am

Let’s call you the bug eraser , well done :)

Image
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Re: Space Shuttle

Postby eatdirt » Wed Nov 07, 2018 11:32 am

I think I found it - wrong branch of the angle picked by an acos, feeding into a sine later would reverse the sign - the bug would be apparent after exactly 12 hours and heal itself after another 12 hours.


:D YES!! Well done!! I'll test the latest devel. You rock!
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Re: Space Shuttle

Postby GinGin » Thu Nov 08, 2018 5:05 pm

@WlBragg:

A quick insight of the last 2 mn of approach :)

https://forum.flightgear.org/viewtopic.php?f=19&t=35001
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Re: Space Shuttle

Postby Thorsten » Fri Nov 09, 2018 8:54 am

Kit to RCS crossfeeds should now be okay (at least if you follow nominal procedure and only ever connect one feeding tank to the manifold -and isolate the rest - if you open several crossfeed path by having both kit and OMS tanks connected to the manifold with the RCS thrusters sucking propellant, I believe you might pick the OMS preferentially and never reach to the kit.

Probably one should compare tank pressures, but with the possibility to disconnect helium and reduce tank pressures, there's also the possibility of backward flow, which however should be inhibited by special valves,....

I'd rather not go there.
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Re: Space Shuttle

Postby GinGin » Fri Nov 09, 2018 10:21 am

Very nice :)

I was reading some exotic procedures for deorbit burn concerning mixed crossfeeding ( for example right pod Fuel with left Pod Oxydizer for left engine)
Impossible to do manually with switches as it will open both fu and ox valves for a side. Aim was to have an acceptable lateral CG for entry

It was done by letting the switches on GPC and loading a soft into the GPC to open specific valves

They thought to so many possibilities, quite outstanding.
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Re: Space Shuttle

Postby GinGin » Fri Nov 09, 2018 11:41 am

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Re: Space Shuttle

Postby wlbragg » Fri Nov 09, 2018 11:55 am

We're pretty close, we just need the hydraulics! :lol:
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Re: Space Shuttle

Postby Thorsten » Fri Nov 09, 2018 6:58 pm

It was done by letting the switches on GPC and loading a soft into the GPC to open specific valves


Yeah, read about that one, the procedure seemed pretty nasty with applying a patch to the software... I'm not sure we'll get there (but who knows...).

I'll try to add support of more than one OMS kit next - if the crossfeeding from one kit works, we should get by with transfering propellant from the outermost kit inward (?) - which is comparatively easy.

(Did I mention that support for fuel systems in JSBSim suc&^% ??? )
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Re: Space Shuttle

Postby GinGin » Fri Nov 09, 2018 7:10 pm

I'm not sure we'll get there



I am not even sure they were practicing that in real seeing how special it was xD


(Did I mention that support for fuel systems in JSBSim suc&^% ??? )



Argh, fuel leaks everywhere :mrgreen:
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Re: Space Shuttle

Postby wlbragg » Fri Nov 09, 2018 8:32 pm

Here is what I have modeled for the OSM PBK so far. Not having documentation on it makes for a lot of speculation. Was this ever actually produced and used?
If not then I guess my version of it is good enough.

Image
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Re: Space Shuttle

Postby eatdirt » Fri Nov 09, 2018 9:40 pm

Did I mention that support for fuel systems in JSBSim su...


I think I noted that RCS tanks get slowly refurnished during a OMS->RCS crossfeed, even though I *think* I followed the procedure properly. Dunno if someone noted this too, or if I've made (again) a mistake...

In fact, like this one, I have a small list of glitches that I might mention, they're really small things and please do not feel obliged to look at them, but in case someone see them, that could confirm they really do exist:

- From OMS 303 -> OMS 304, the ADI ball in DPS A/E mode and LVLH shows the REF yaw number (I mean something which is no longer 0, and compatible with what you get in REF mode). But using the "big" ADI ball, DPS / ORBIT in LVLH everything is fine.

- When checking with MCC the Shuttle weight before and after an OMS burn, it looks like the DPS is computing a fuel weight removal larger than what it is systematically.

- Objects released from the Shuttle, payload satellites, jettisoned Ku-Band antenna [when Direct Stow does not solve the Antenna stowing, that works 100% of the time :)], seem to drift quite fast and systematically in the same direction, even if the Shuttle is in FREE mode. I guess the Shuttle should not have too much acceleration in FREE mode, up to some leakages but I've checked a few times that all valves are closed, no running FES.

- Sunset, sun behind the Shuttle. Reddish lights enters the Shuttle, very nice, becomes redder and redder as I would have expected, but suddenly, flash back to white for a little while just before the sun disappears. Maybe that's an expected effect, but since my only experience up-there is with flightgear, I don't know :)

Please don't flame me, that's all what I can find now in the little corners of the STS, small things, and that's just great!!!!

@wlbragg, you rock, that is A.M.A.Z.I.N.G.

In one of my post above, there is a paper explaining what could have been done with the kit, but, no it was never installed nor built. That means, that you and Thorsten could actually put your logo/pseudo/name on it. We have the Canadarm, the NASA STS and the Thorsten & Wlbragg PBK, I'll be happy to see that from the payload specialist window, much deserved. Thank you so much guys!!

Cheers,
Chris.
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Re: Space Shuttle

Postby wlbragg » Fri Nov 09, 2018 9:52 pm

Interesting, I was looking at
https://cp3.irmp.ucl.ac.be/~ringeval/upload/spaceshuttle/PBK/shuttle_perf_with_omskit.pdf
and notice there was to be a 500 fps, 1000 fps and 1500 fps. The model I made is the 1500 fps

Structural weight 5157 lbm
Usable propellant weight 36,396 lbm
Total propellant weight at launch 43,253 lbm
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Re: Space Shuttle

Postby eatdirt » Fri Nov 09, 2018 10:29 pm

The model I made is the 1500 fps


YES! that is PERFECT

I'll be able to practice my most favourite activity with the Shuttle these days, which is going into high and quite elliptical orbits 8)

@Thorsten, I've been playing with i-files, and I can reach 600 miles from KSC, 39 degrees of inclination with MPS at MECO. That's cool, but I am wondering if this is really possible or am I playing with a parameter I should not play with!?
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