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Author Topic: ORDEAL Development Thread  (Read 16274 times)
Swatch
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jasonims
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« Reply #15 on: July 25, 2007, 10:17:45 AM »

no, I'm not going to work on the ORDEAL, so have at it. When I said I'd look into making some psuedo-code, it was more saying if nobody was going to work on it, then I'd look at doing it, but I had no intention on putting much into it.  You have a much better handle on the control systems of the CM, so I'll leave that one to you.  Happy

Anyway, I'm enjoying the VirtualCapCom challenge much more right now... Wink
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My Project Apollo Work:
CM Visual
 -VC (~75% complete: texture work beginning again; mesh-78%; texture-70%)
Propulsion Particle Improvements (Focused on S1B right now, BETA 1.0 has been commited)
New Docking Method (~50% complete: research complete; coding partially completed, testing not underway)

Future Work:  (if it's here, it's deemed unnecessary to upcoming release)

Older Work:  (if it's here, it's fair game to whoever wants to improve)
EMS Implementation (committed: minor flaws, but groundwork is there, needs extensive testing)
EMS scrolls (committed: not refined, but usable)
SM Visual (committed: mesh-finished, texture-60%; possibly revisited in future)
J2 Texture (commited: room for improvement)
LRV (committed: mesh-finished, texture-90%; in future a ground up rebuild may be in order, but not on my plans)
Tschachim
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« Reply #16 on: July 25, 2007, 10:19:58 AM »

OK, then I'll take a look at the ORDEAL.  Happy
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Coussini
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« Reply #17 on: July 25, 2007, 10:28:11 AM »


Tschachim, thanks again Wink

If you want to know what i'm doing, you can Check theses documents... I created many document on NASSP. SOO...

The recent one on the DISPLAY AND MANOEUVRE
http://www.filehost.gr/download.php?file=1e03bcac0e38cff094ff3ee475ec267a

DSKY PRESENTATION
http://orbiter.mustard-fr.com/tutorials/download.php?file=Presentation_du_DSKY

AND THE BIG ONE ABOUT MOON MISSION
http://orbiter.mustard-fr.com/tutorials/download.php?file=Objectif_lune_pour_Apollo

MOON PROCEDURE USING APOLLO 12
http://media6.filewind.com/g.php?filepath=13482

it's a begining... but you can see why i want to know on ordeal.

IT'S LONG TO CREATE A DOCUMENT, SO I SHOULD DO A FORCAST TO MAKE SURE THAT IS READY WHEN THE ADD-ON IS READY.

« Last Edit: July 25, 2007, 10:54:44 AM by Coussini » Logged

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Christophe
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« Reply #18 on: July 25, 2007, 10:47:49 AM »

Quote from: Coussini
During the TLI burn, the guidance of the vehicle will be monitored using the FDAI in front of the Commander. The Saturn third stage will pitch up at a preprogrammed rate as the burn continues and the ORDEAL will drive the FDAI at a matching rate to compensate for the pitch motion. This will allow the FDAI to indicate a zero attitude all through the burn. Therefore, if necessary, the burn could be steered manually by Dave, just by keeping the FDAI and the associated rate needles zeroed.

Not at all!
The Ordeal is an additional box that is only installed by the CDR after otbit insertion. Additionnally the Ordeal can only give a constant rate so it cannot follow the launch pitch program.

See also the abort procedures, especially mode III and IV: You will see that the FDAI angles for reentry are from the launchpad refsmmat (inertial).

Quote
Probably, the CM have an automatic feature like PROGRADE to maintain the CSM in the proper ATTITUDE in orbit
Neither! The prograde mode is an orbiter feature, not an Apollo one  Happy

As far as I know, in order to keep the CSM in the proper attitude while ordeal is working (orb rate attitude) it's exactly the same way than usual. You set an attitude with the DSKY (N17, total astronaut ATT, see G&C checklist) and the DAP will follow the error needles. For the autopilot it's exactly the same to maintain a fix attitude (rate 0) or a constant rate...

Tschachim!
If you works on the Ordeal. Be carefull with the orbital period! Those display in orbiter is wrong due to the fact that it takes the keplerian osculating orbit at a specific instantaneous time. But the true period (perturbated orbit) is quite different. Generally a bit smaller.
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Tschachim
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« Reply #19 on: July 25, 2007, 10:53:18 AM »

I'M NOT A JOKER... I JUST WANT TO KNOW.

Sorry if I bothered you, but I don't understand.  Confused

If you works on the Ordeal. Be carefull with the orbital period! Those display in orbiter is wrong due to the fact that it takes the keplerian osculating orbit at a specific instantaneous time. But the true period (perturbated orbit) is quite different. Generally a bit smaller.

Thanks for pointing that out. First of all I need to read and understand the ORDEAL docu anyway and it would be great if I can bother you with questions about it after that's. Happy

Cheers
Tschachim
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Coussini
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« Reply #20 on: July 25, 2007, 10:56:47 AM »

I'M NOT A JOKER... I JUST WANT TO KNOW.

Sorry if I bothered you, but I don't understand.  Confused

If you works on the Ordeal. Be carefull with the orbital period! Those display in orbiter is wrong due to the fact that it takes the keplerian osculating orbit at a specific instantaneous time. But the true period (perturbated orbit) is quite different. Generally a bit smaller.

Thanks for pointing that out. First of all I need to read and understand the ORDEAL docu anyway and it would be great if I can bother you with questions about it after that's. Happy

Cheers
Tschachim

I MADE A MISTAKE WHEN I READ YOUR ANSWER AND I'M NOT FINISH IT....  SORRY  Embarassed

MY ENGLISH WAS NOT VERY GOOD... BUT I JUST CHANGE MY ANSWER BEFORE YOUR ANSWER. Thanks and excuse for that mistake.

You're welcome to see my document...
« Last Edit: July 25, 2007, 10:59:44 AM by Coussini » Logged

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mikaelanderlund
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« Reply #21 on: July 25, 2007, 11:51:38 AM »

Yoda Happy

Mikael
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Coussini
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« Reply #22 on: July 25, 2007, 11:54:42 AM »

Quote
..... During the TLI burn, the guidance of the vehicle will be monitored using the FDAI in front of the Commander. The Saturn third stage will pitch up at a preprogrammed rate as the burn continues and the ORDEAL will drive the FDAI at a matching rate to compensate for the pitch motion. This will allow the FDAI to indicate a zero attitude all through the burn. Therefore, if necessary, the burn could be steered manually by Dave, just by keeping the FDAI and the associated rate needles zeroed.
....

Not at all!
The Ordeal is an additional box that is only installed by the CDR after otbit insertion. Additionnally the Ordeal can only give a constant rate so it cannot follow the launch pitch program.

See also the abort procedures, especially mode III and IV: You will see that the FDAI angles for reentry are from the launchpad refsmmat (inertial).

I saw this in the APOLLO 11 ... and i know that the PROGRADE is not the real procedure. I just want to inform that is similar. Wink

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Christophe
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« Reply #23 on: July 27, 2007, 10:20:55 AM »

Quote from: Tschachim
understand the ORDEAL docu anyway and it would be great if I can bother you with questions about it after that's.

No problem!  Happy

 
Quote from: Coussini
saw this in the APOLLO 11 ... and i know that the PROGRADE is not the real procedure. I just want to inform that is similar.

Yes. That's what I wanted to point out: ORDEAL is an additional box that is mounted after orbit insertion by the CDR.  Thumbs Up
« Last Edit: July 27, 2007, 11:33:10 AM by Tschachim » Logged
Tschachim
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« Reply #24 on: August 14, 2007, 01:21:54 PM »

If you works on the Ordeal. Be carefull with the orbital period! Those display in orbiter is wrong due to the fact that it takes the keplerian osculating orbit at a specific instantaneous time. But the true period (perturbated orbit) is quite different. Generally a bit smaller.

Well, it looks like the ORDEAL will disappoint you. Once configured it just drives the FDAIs pitch axis at a constant rate, so it only works precisely when the spacecraft x-axis is in the orbital plane in a circular orbit (in a spherical field), far away from considering non-spherical fields. Moreover the orbital period isn't calculated properly from the Earth/Lunar and altitude switch settings, but a linear approximation is used. You'll find details about that here: http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19740026211_1974026211.pdf

So it's not that difficult to implement it since it's a quite simple device, but given all these restrictions do you still want to have it?

Cheers
Tschachim
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Christophe
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« Reply #25 on: August 30, 2007, 10:24:46 AM »

Sorry for the late reply.
Yes of course I want it!  Excited!
Even if this what you describe. In fact I know that and that's how Apollo worked, so that's how I want to do.  Happy

Do you think you could implement it in NASSP?
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Swatch
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« Reply #26 on: August 30, 2007, 12:10:19 PM »

The biggest advantage to having it is that even though it doesn't completely keep you perfectly in prograde, it does keep your orientation fairly close to prograde.
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My Project Apollo Work:
CM Visual
 -VC (~75% complete: texture work beginning again; mesh-78%; texture-70%)
Propulsion Particle Improvements (Focused on S1B right now, BETA 1.0 has been commited)
New Docking Method (~50% complete: research complete; coding partially completed, testing not underway)

Future Work:  (if it's here, it's deemed unnecessary to upcoming release)

Older Work:  (if it's here, it's fair game to whoever wants to improve)
EMS Implementation (committed: minor flaws, but groundwork is there, needs extensive testing)
EMS scrolls (committed: not refined, but usable)
SM Visual (committed: mesh-finished, texture-60%; possibly revisited in future)
J2 Texture (commited: room for improvement)
LRV (committed: mesh-finished, texture-90%; in future a ground up rebuild may be in order, but not on my plans)
Christophe
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« Reply #27 on: August 30, 2007, 12:21:36 PM »

The biggest advantage to having it is that even though it doesn't completely keep you perfectly in prograde, it does keep your orientation fairly close to prograde.

And above all it can maintain you in an attitude perpendicular to the surface (that can be told as the same as perpendicular to the velocity vector in a near circular orbit) which is very practical for docking/undocking and separation in a equiperiodic orbit change.
Don't forget that the purpose of ordeal is not only "prograde" (which has only a few interest) but mainly to keep any attitude in reference to the local vertical.
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Tschachim
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« Reply #28 on: August 31, 2007, 08:31:32 AM »

Do you think you could implement it in NASSP?

Yes, I think I'll give it a try, I see 2 panel related problems, though:

  • I think we need a very fine-grained altitude rotray switch with much more positions than our current switch has. Moonwalker, you would be the man for that, but perhaps I can do that by myself since it's just rotating a bitmap a couple of times.

  • I think I need to create a possibility to display/blit the ORDEAL panel on the main panel near the FDAIs optionally, because for initial ORDEAL setup you need to slew the FDAIs with a switch on the ORDEAL panel while watching the FDAIs simultaneously. Programming-wise it's no problem, but it's not realistic, but otherwise I fear the ORDEAL would be quite unusable.

Comments/suggestions and help is always appreciated as usual.  Happy

Cheers
Tschachim
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Swatch
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« Reply #29 on: August 31, 2007, 09:31:59 AM »

How bout we make the ORDEAL a pop-up on the main console window, much like the difference between being stowed vs, being in use.  Just have a click-area on top of the upper left rendevous window, and if you click there, the ORDEAL pops up, then have a generic X-button on the upper corner of the ORDEAL visual you just made. You could hide it in one of the screws on the ORDEAL's face.
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My Project Apollo Work:
CM Visual
 -VC (~75% complete: texture work beginning again; mesh-78%; texture-70%)
Propulsion Particle Improvements (Focused on S1B right now, BETA 1.0 has been commited)
New Docking Method (~50% complete: research complete; coding partially completed, testing not underway)

Future Work:  (if it's here, it's deemed unnecessary to upcoming release)

Older Work:  (if it's here, it's fair game to whoever wants to improve)
EMS Implementation (committed: minor flaws, but groundwork is there, needs extensive testing)
EMS scrolls (committed: not refined, but usable)
SM Visual (committed: mesh-finished, texture-60%; possibly revisited in future)
J2 Texture (commited: room for improvement)
LRV (committed: mesh-finished, texture-90%; in future a ground up rebuild may be in order, but not on my plans)
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