Passive Thermal Control (G&N)

flyjonny

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Hi everyone.

First time posting here, and I'm hoping to contribute in the near future. While I wrap my head around the project on Github, during my Apollo 11 mission, I was trying to establish the PTC with G&N and the autoroll didn't start. I picked up the CMP checklist and I noticed an error. In the "Select roll rate" block of the checklist, when typing in the second V24, it's only V24E and not V24N01E. Typing in N01 seems to not lead to the start of the roll maneuver. The docs should be updated (I could do a pull request for that), but I'm not sure if the MFD reads the checklist directly from the docs, or if it's somewhere else in the project.

Also, I like to time warp during PTC. By time warping, the time integration will be larger. From what I have seen, it will either create instabilities or burn more RCS propellant. In my Apollo 8 mission, with a PTC with SCS, I slowed time to 0.1x to try to null as much as possible as it reduces the time integration for either MIN IMP or ACC commands. Anyone has any tips on how to handle that?

Thanks, and I'm looking forward to possibly make some contribution on the project in the near future.
 

flyjonny

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Here's the CMP checklist as a reference. It was the first two times I ran this checklist, it's a bit different than what I did during Apollo 8. I want to read it in the AGC documentation on this topic. Cheers.

1634745658399.png
 

rcflyinghokie13

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First time posting here, and I'm hoping to contribute in the near future. While I wrap my head around the project on Github, during my Apollo 11 mission, I was trying to establish the PTC with G&N and the autoroll didn't start. I picked up the CMP checklist and I noticed an error. In the "Select roll rate" block of the checklist, when typing in the second V24, it's only V24E and not V24N01E. Typing in N01 seems to not lead to the start of the roll maneuver. The docs should be updated (I could do a pull request for that), but I'm not sure if the MFD reads the checklist directly from the docs, or if it's somewhere else in the project.

While you are correct it is different than what is written verbatim in this procedure, the extra N01 makes no difference in this matter as V24 by itself just allows entry in the first two registers of the current N01. I just tested and the PTC works just fine. I will, however, edit the procedure to match this just for clarity.
 

flyjonny

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While you are correct it is different than what is written verbatim in this procedure, the extra N01 makes no difference in this matter as V24 by itself just allows entry in the first two registers of the current N01. I just tested and the PTC works just fine. I will, however, edit the procedure to match this just for clarity.
That's what I wasn't sure if it was supposed to make a difference or not. I probably made a mistake in the PTC checklist on the first try. I'm not into a program, I'm not loading a command thru a verb (like we do with V48 or V49, for example). It's the first time I encounter an input to the AGC this way and I'm doing the inputs on blind faith from the checklist without knowing exactly what I'm doing. I want to read further on what am I inputting thru the DSKY here. Thanks for your help!
 

rcflyinghokie13

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That's what I wasn't sure if it was supposed to make a difference or not. I probably made a mistake in the PTC checklist on the first try. I'm not into a program, I'm not loading a command thru a verb (like we do with V48 or V49, for example). It's the first time I encounter an input to the AGC this way and I'm doing the inputs on blind faith from the checklist without knowing exactly what I'm doing. I want to read further on what am I inputting thru the DSKY here. Thanks for your help!
So that's the difference between extended verbs and action verbs. V48 and V49 are extended verbs so they call a routine. V24 just essentially says "write in R1 and R2" on a noun display. So in that case since N01 is already up, V24 just simply says, in that case "write in R1 and R2 of N01."
 

Miriam

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I want to read further on what am I inputting thru the DSKY here.
I haven't found any explanation on this procedure, but from my (rudimentary) knowledge of the DAP, you're sort of spoofing it by entering the desired rate directly into the respective memory locations. Normally this would be done by dedicated routines like KALCMANU (the routine behind V49), but here we do it manually.
Don't twist my arm on this, though. I think I understand the basic principles behind the DAP, but how it works codewise: ugh. That thing is surely the most complex piece of code in the whole software, with routines meshing with each other, ISRs doing their thing and other black art going on.
 

flyjonny

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I haven't found any explanation on this procedure, but from my (rudimentary) knowledge of the DAP, you're sort of spoofing it by entering the desired rate directly into the respective memory locations. Normally this would be done by dedicated routines like KALCMANU (the routine behind V49), but here we do it manually.
Don't twist my arm on this, though. I think I understand the basic principles behind the DAP, but how it works codewise: ugh. That thing is surely the most complex piece of code in the whole software, with routines meshing with each other, ISRs doing their thing and other black art going on.
Thanks for that answer. That's what I thought that we entered the rate directly into memory. I'll try to read about that routine to see if I can dig a bit deeper.
 
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