News The Space Shuttle for Flightgear 3.6

Thorsten

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A special treat for those enjoying emergencies in space - there's now a viable simulation of a fire in an avionics bay.

Here's the SM SYS SUMM 1 display showing the increasing smoke concentration in avbay 2 (and to a lesser degree in the other detectors) during the second fire test.



(upper left, the alarm trips as soon as the value reaches above 2.0, here we have 7.9)


The fire can be extinguished by applying halon, that's already simulated, and if unchecked it will destroy gradually more and more equipment in the avionics bay (that's also simulated) - what's sill missing is tripping the HW smoke detection and hooking up the in-cockpit switches to apply halon.

(As a side note, I realize just this moment that now finally all values on this page are driven by actually simulated data...)
 

Gingin

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Impressive, pretty high concentration of smoke
I already hear the strident siren and the master Alarm :lol:
 

Thorsten

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Ever wished for the ultimate HW to run the Shuttle sim?

Stafford Air and Space Museum got the NASA fixed base simulator



- and I've just been contacted by the company preparing the exhibit about how the FG Shuttle can be rigged to drive the displays and external visuals.

I guess that'd be the ultimate way to enjoy the sim (I am so envious - I wanna fly this...)
 

Thorsten

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How many gb is this gonna be ?

That's the whole aircraft repository (about 30 GB I think) - with svn, you can checkout 'any subdirectory (see here for instructions).

But if you want to try the stable version, you don't need repository magic - FG itself will offer you the option to download that (via http) in the launcher.

What GinGin linked is the devel version - that's a GIT repository - which is large, but more manageable with a shallow checkout - needs some GitFu to do - and is really the devel version, i.e. among all new features, you also get to follow all the breakage the new features cause.
 

Thorsten

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Doing the last leg to ISS, from a phasing orbit about 15 km lower and 120 km behind right to a vbar stationkeeping position off ISS.

Preparation starts during dusk over Africa - see the illumination on the horizon? That's a tropical thunderstorm raging...



The on-board Lambert solver spits out a transfer solution:



The solution gets transferred to MNVR and translated into a burn program:



Egypt and the Nile delta seen out of the window while the Shuttle moves into burn attitude (the terrain is unusually bright since we have full moon illuminating bright desert sand here...)


The transfer burn with Israel seen in the foreground:



Aurora on the horizon as we pass over central Asia.



The Lambert solver spits out a trajectory correction:



After we've burned the correction, it provides the braking burn:



Sunrise on the horizon...



... and we fly into morning.



Light plays on the interior as the Shuttle moves into attitude for the braking burn...





The OMS fires with ISS already visible a few miles off



And, after some manual corrections, the view through the overhead window - the Shuttle hanging in the vbar of ISS, ready to get closer whenever this is required.

 

Wolf

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Awsome, thanks for sharing this. I dream of the day we will have this for SSU. Have the FG earth textures been improved recently? View from orbit looks very similar to Orbiter 2016 (D3D9).
Question: here the rendezvous brings the shuttle on the VBar (usually the final burns put the orbiter behind and below the ISS in order to perform an RBar approach). I guess the VBar approach was done on purpose in your example, right?
 

Gingin

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Very nice Thorsten, I have a lot of fun testing that

@Wolf: there are different level of textures, that must be the HD one which look pretty good :)

( You can use Spec 34 on SSU also, it works as intended ( minus one or two options that is not simulated, but not "mandatory") )
 

Thorsten

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Have the FG earth textures been improved recently? View from orbit looks very similar to Orbiter 2016 (D3D9).

I suppose ultimately we all use NASA's Pale Blue Marble - so similarities might be natural :lol:

Otherwise Earthview has been like this for a while (the linked post is from 2016) - I'm occasionally adding details like the thunderstorms or relief shading of the clouds in moonlight when I feel like it (and it doesn't come with hires textures with a vanilla FG install, they're like four times the size of the base package, so they're distributed as addon).

The reason that you only see this in some of my pictures is that I have a customized Shuttle development setup which is rigged to start up as quickly as possible, i.e. it really is 'no frills' (as you might imagine, I end up re-starting the sim quite a lot when developing or debugging) - when I make a quick demo with this, the visuals are usually more simple, when I use the current FG version for testing (or my enjoyment) you see hires textures and all the goodies.

I dream of the day we will have this for SSU.

I'm fairly sure rendezvous is something SSU currently supports much better (GinGin might know about the targeting accuracy, but mine isn't too great since unlike Orbiter, I can't really simulate the orbital dynamics of multiple objects, so I have to cheat (which involves a semi-analytic orbit switched over to a numerical simulation in the vicinity) - that works but introduces a small but measurable amount of artifacts.

Not sure to what degree I can beat them down. )

I guess the VBar approach was done on purpose in your example, right?

Yes - I'm slowly working through testing different scenarios to see where the main remaining issues are, so I try all sorts of goofy things (you'll also note that the solution has a large radial velocity component and isn't very propellant-friendly - simply waiting a little would have given a better one...)
 

Wolf

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I think SPEC 43 works in SSU (with a scenario editing).

My bad, SOEC34 is indeed there. I guess I ve been tricked by the wish of having the capability to launch, phase, rendezvous and dock fully implemented..
What is the scenario editing required that you mentioned?
 

Thorsten

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I guess I ve been tricked by the wish of having the capability to launch, phase, rendezvous and dock fully implemented..

I'm not exactly sure what you're missing? I thought GinGin has done a successful rendezvous re-creating the early assembly of ISS with SSU of late?:idk:

Otherwise, years ago I even managed to fly stock Atlantis to ISS with some pen and paper navigation and nowhere near the support an automated launch or SPEC 34 targeting provides (granted, the spacecraft might be a tad more maneuverable than the real Shuttle, but since all has to be flown manually...) and managed to dock without attitude-hold DAPs etc.

So I guess I'm a bit confused here, I was under the impression Orbiter basically has it all out of the box and only I have to fight to make a flightsim provide orbital stuff...
 

Wolf

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I'm not exactly sure what you're missing? I thought GinGin has done a successful rendezvous re-creating the early assembly of ISS with SSU of late?:idk:

Otherwise, years ago I even managed to fly stock Atlantis to ISS with some pen and paper navigation and nowhere near the support an automated launch or SPEC 34 targeting provides (granted, the spacecraft might be a tad more maneuverable than the real Shuttle, but since all has to be flown manually...) and managed to dock without attitude-hold DAPs etc.

So I guess I'm a bit confused here, I was under the impression Orbiter basically has it all out of the box and only I have to fight to make a flightsim provide orbital stuff...

I am referring to some WIP on the DAP for example (launch and MECO as well as reentry) GLS is working on and some missing DPS and MEDS functions plus the long discussed need of some kind of Mission Control implementation. The devs have been discussing some of this stuff on this same thread many times.
Said that I know we can still launch, rendezvous and dock using sone generic MFDs and/or paper and pencil.
 

Gingin

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@Wolf: I answer you in SSU questions thread for the Spec 34 stuff :)
Yes, concerning the MCC is always subject to debate.
In my opinion, using MFD like Orbit or align plane is not cheating. They have probably the same kind of software, if not even more accurate one in MCC nowdays.
So I guess a mission Control implementation will just give you the value of a burn , and now we have to find those burn ourselves and understand even better what we want to do.
It's even harder like that. We can do a complete nominal mission following Nasa rendez vous logic by the book with what we have now ( and a lot of papers yes ;) )


@TMaC: There are already plenty of documentations/tuto ;)

http://wiki.flightgear.org/Space_Shuttle

http://wiki.flightgear.org/Space_Shuttle#Mission_phases
 
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Thorsten

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I am referring to some WIP on the DAP for example (launch and MECO as well as reentry) GLS is working on and some missing DPS and MEDS functions plus the long discussed need of some kind of Mission Control implementation.

So forgive my ignorance (I'm only loosely following SSU development and not reading every detail) - what level of MCC would you like to have?

As for myself, I much prefer to arrange the simulated world to my needs (i.e. I have orbital rendezvous targets configurable), and for anything that requires MCC computing capabilities, I simply use LEO Targeting (as I would for a whole mission design) - with that, I can quickly try out things, fit optimal transfers or visualize what is going to happen without the need of running a whole simulation in the background.

So basically should I ever have the time (and that's a big if), I'd design my mission up-front using LEO targeting, use the results of that exported as PEG-7 targets in the simulation, use the in-sim MCC visualization tools when needed (I have a trajectory map, an ECAL map and the rendezvous coordinate display so far) and otherwise rely on the Shuttle avionics where possible.

Pretty much all of that seems quite possible in Orbiter as well, so I'm trying to find out what you're seeing I'm not.


Okay, someone is going to have to do a tutorial on how to read those MFD screens.

Try the DPS dictionary...

Generally, anything Shuttle really requires lots of context to understand and you can't learn it quickly. I've tried to provide a human-readable version in my FGShuttle Flight manual, the basic edition you can get from here if you want, but still that's a hefty read.
 

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Okay, let's continue where we left off - on the vbar of ISS. The Shuttle is not put vertical with the payload bay pointing towards ISS - that allows good operations of the Ku-antenna as radar ranging device. The REL NAV display shows the radar ranging data, while the Shuttle is piloted looking upward out of the overhead windows towards ISS.

Luckily, the controls can be adjusted to fly 'normally' from that perspective - in Orbiter I had docked stock Atlantis once to ISS where it isn't possible to switch the control sense, and I found my brain in a tight knot pretty fast...)



Approaching on the vbar - orbital mechanics requires us to regularly null the vertical speed, the orbiter wants to go upwards relative to the station.



Aiming below ISS to get into the rbar position...



... and on the rbar, rotating and switching to LVLH mode to lock attitude with respect to the horizon (and ISS)



Going up the rbar - when only a small upward velocity is used, orbital mechanics will provide a braking force, so we don't have to fire upward thrusters to brake, frying the station in the process...



Nearly there (took a while, slow does the trick...)



... and just before sundown, docked properly



Docked to ISS now, nice aurora display around the South Pole:



Just as the Rendezvous workbook states, the Achilles heel of the whole thing is the FRCS - most translation maneuvers use the FRCS, but its propellant can't be cross-fed from the OMS, so once it's gone, translation capability is gone. Thus, one would have to be really careful about conserving RCS propellant (my approach was far too hasty to be propellant-friendly...)
 
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