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Space Shuttle - Flight

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Re: Space Shuttle - Flight

Postby GinGin » Mon Feb 15, 2021 6:35 pm

Last adventures:

A TAL to Moron , aborting the Orbit Insertion for Hubble .

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Slightly low on Potential Energy ( a bit below the path) but our Kinetic energy is ok, hence a total energy almost nominal

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Runway in sight

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Long time I didnt play with Night Landing, always entertaining

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Second exercise, an Abort Once Around due to a leak in the Pilot window seals ( always the fault of the first officier :mrgreen: )

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Easy enough to target the Deorbit burn peg4 parameters with the LEO tool and the AOA cue card burn data in the ascent FDF

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Waiting the Deorbit burn, going from Sun to Aurora

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A bit of OMS pods thermal management

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Mostly radial up burn to move the apsis line

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An entry started in the darkness

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With the sun showing up again

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Final fault for today, an indication that our APU fuel is becoming Low, but not critically low
Plus we are almost on the nominal entry path, less than 1 ft.s² of drag difference between the actual and required one

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Then I lost the control during TAEM :mrgreen:
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Re: Space Shuttle - Flight

Postby GinGin » Wed Feb 17, 2021 12:05 am

Low pass day

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V1, Rotate, Vsleep :mrgreen:

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Re: Space Shuttle - Flight

Postby GinGin » Wed Feb 17, 2021 5:14 pm

Another nice scenario, a Low Energy TAL to Banjul, aborting once again our meeting with Hubble


Boundary datas for Equatorial Launch ( 28.6°)

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Failure at 7000 ft/s, and manual cutoff at 22700 feet/s to be in the Low energy aera for Banjul (BYD)

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We have indeed a low situation ahead of us, Item 3 will be a nice help.
We are a bit on the right side of the entry envelop.

Nominally, we should have been close to the nominal third line by starting from the left. Our Drag would have been then 15 ( Dref in red for our current relative speed of 22000 ft/s)
At our range, the nominal vertical speed would have been -66 ft/s like indicated by the purple cues ( but that is for a nominal speed of 23500 feet/s)
So we are way off the nominal cue; not usable that far away from a normal entry.

But we can use the dynamic cues.
In blue, our actual drag (18ft/s²), and increasing rapidly as we dive into the atmosphere ( TAL drag spike)
In Yellow, the drag required by guidance to bring us back later on in the envelop(10ft/s²)

So we need to go up in the atmosphere again to decrease our drag, hence the Vertical speed bias ( hdot bias) which wants us up there.

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TAEM interface, Overhead HAC entry for the Runway 14

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Nav delta state vector update requested by MCC as no MLS available

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Large HAC, Overlay and state vector within limits

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Savana landing

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Re: Space Shuttle - Flight

Postby GinGin » Thu Feb 18, 2021 5:22 pm

More tests


TAL to Istres

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IFR obstacle clearance problem :mrgreen:

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Easter Island and its sloped runway

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Re: Space Shuttle - Flight

Postby Thorsten » Sat Feb 20, 2021 5:12 pm

Some impressions from the new Lakebed landing scenario:

Ready for entry:

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Plasma building up:

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Now it gets hot...

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Western US from really high up (this part is very scenic):

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Did I mention that the view is very scenic?

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TACAN data coming in and being incorporated:

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Reaching the landing zone:

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... and touchdown. Could it be that we have spray for rain on the runway but no dust for the lakebed landing?!

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Re: Space Shuttle - Flight

Postby GinGin » Sat Feb 20, 2021 6:32 pm

The glow inside the cockpit with the lighting effects are really nice
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Re: Space Shuttle - Flight

Postby eatdirt » Tue Feb 23, 2021 10:29 pm

Hi guys,

On SPEC 33, I am seeing Ydot < 0, and for a Y negative , Y increases (towards 0). When Ydot > 0, still with Y negative, Y becomes even more negative! Is this a funny NASA convention, or do we have a sign error here? (did not test yet with Y>0).

Edit: I have encountered catastrophic errors later on in trying to station keep with HST. At some point, I put Eileen on command, she managed to null vx on the RDV dialog and still the HST was escaping at more than 10m/s along the x axis. I did not manage to actually see the 3D model although my closest encounter was at less than 1000ft on x and tens of ft on z/y. Maybe the proximity zone was not triggered for HST? Did some of you try a rdv with it?

Thanks,
Cheers,
Chris.
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Re: Space Shuttle - Flight

Postby Thorsten » Wed Feb 24, 2021 7:58 am

:
I have encountered catastrophic errors later on in trying to station keep with HST.


Eileen can hold a stationary position with respect to something, but she can't acquire the position- if you have non-zero velocities when engaging the mode, she won't null them properly and return to the position where you engaged AP.

Also, it seems to work for the time you need to grab a satellite, but currently the mode doesn't have long-term stability (that became very obvious when I tested the coarser levels), so it's on the 'need to debug' list - probably there's a logical error somewhere in the decisionmaking tree.

[quote[I put Eileen on command, she managed to null vx on the RDV dialog and still the HST was escaping at more than 10m/s along the x axis.[/quote]

That sounds like her using ISS as reference object rather than the HST... :?:
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Re: Space Shuttle - Flight

Postby eatdirt » Wed Feb 24, 2021 1:30 pm

Eileen can hold a stationary position with respect to something, but she can't acquire the position-


You're clearly underestimating her (your?) skills :D
I actually tested her quite a long time ago with ISS, precisely to cancel residual speeds after T2 from my crazy air-to-air Lambert-Hohmann transfers, and although she burnt almost all the fuel, she really managed to zero all relative velocities from 20ish ft/s!! She's good!!!

Seriously, here for HST, I was unable to achieve anything close to station keeping while I was quite close and not too fast; hence my desperate move to try Eileen! And she did manage to 0 vx here as well! In fact everything was looking like I never entered the proximity zone (especially the fact that the 3D model was not visible). But I'll retest all this (got a saved snapshot in Lambert transfert to HST).
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Re: Space Shuttle - Flight

Postby Thorsten » Wed Feb 24, 2021 6:34 pm

You're clearly underestimating her (your?) skills :D


I might... She's just a bit quirky for me :?

I'm slowly hammering down reasonable initial conditions and checklist changes for a de-orbit scenario. I've had quite a good flight today, no serious bugs, just a few quirks which we hopefully will be able to address eventually. My goal is that the in-sim checklists contain all items that you need to avoid failure messages, let's see how far we get.

One observation was that it seems hard to avoid FREON LOOP warnings - if I have the high-load evaporator on it gets too cold, if I have it off it gets too warm, so one kind of needs to monitor evaporator out temp at all times and switch the high-load evap on and off as needed :? Anyone else has any experiences with that?
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Re: Space Shuttle - Flight

Postby GinGin » Wed Feb 24, 2021 6:51 pm

It is what I do for the freon , controlling the Temperature through the Hi load switches mainly so far.
Later in the entry , the freon alarm is more relevant with the activation of nh3 boiler .

So we can put a note for that alarm about the hi load fes monitoring , and that only high freon temperature visible on bfs sm thermal or sys2 can be harmful for systems ?
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Re: Space Shuttle - Flight

Postby eatdirt » Wed Feb 24, 2021 11:43 pm

Anyone else has any experiences with that?


Yes, that's indeed what I do see too. Thermal transfers / FES power, seems to be a bit too fast / too powerful? Again, as you said, if the payload is empty and does not release heat, maybe that is expected?

-----

For HST, I confirm that it fails to load within the proximity zone. In fact, even the console stays silent about any entering in the proximity zone. If I remember correctly, it is verbose for ISS once in.

I am trying to debug with a scenario like ISS-docking but for HST, and without having it as a payload, just to see if it loads in that situation!

But, stupid question: how do I load a custom scenario. In the insim menu, I am seeing only 3 of them, and I've tried
Code: Select all
--aircraft=SpaceShuttle-mission  --prop:/scenario/filename=hst-test.xml


Edit: And you need to go to the menu scenario and press "enter" even though it is written "Nothing selected" :)

Ok, loading it this way works!

Now second stupid question, SpaceShuttle.iss_manager.init is always initialized, but how does it works for SpaceShuttle.hst_manager.init? I do see a call only if it is carried as a payload, but if not?
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Re: Space Shuttle - Flight

Postby Thorsten » Thu Feb 25, 2021 6:58 am

I do see a call only if it is carried as a payload, but if not?


The orbital target code does a handover by name (aka consult a list of objects to load) - that's done inside the proximity_manager class which is in rel_orbital.nas

(Did anyone ever introduce you to the 'grep' command? Searches the whole code for occurrance of an expression in a few seconds and spits out all the relevant lines)

But, stupid question: how do I load a custom scenario. In the insim menu,


If you go through the trouble of coding one, you might as well modify SpaceShuttle/Nasal/canvas/cdlg_scenario.nas and add it in properly, just copy/paste/modify some 4-5 lines in the right section. :D

I guess we /could/ define a slot for 'file specified in the commandline'... But basically I wanted to absorb useful scenarios directly into the distribution.
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Re: Space Shuttle - Flight

Postby eatdirt » Thu Feb 25, 2021 11:34 am

Did anyone ever introduce you to the 'grep' command?


What is it? :) Yea, I missed it... Now I have to chase the values of me.iss_model then, with a very well chosen name for historical reasons I suspect ;)
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Re: Space Shuttle - Flight

Postby Thorsten » Thu Feb 25, 2021 2:26 pm

Now I have to chase the values of me.iss_model then, with a very well chosen name for historical reasons I suspect


Indeed... less risk-prone to keep the old name while developing new features - should be hunted down and re-named eventually though.
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