RCS Best practice Apollo

[indy91]

No wonder you are getting outdated information, that thread isn't even for the Virtual AGC. That is for the old AGC++ simulation in NASSP which has been deleted a few years ago. But I guess there hasn't been a post like that for the lunar rendezvous with the Virtual AGC...

You have to call P32 yourself. I would just follow the Checklist MFD, it has the full procedures for this. I guess the old AGC sim did a lot more automatically that has to be done by hand with the real software. If you want a really detailed explanation of all the programs I would suggest this document: https://www.ibiblio.org/apollo/Documents/j2-80-E-2448-REV1_text.pdf

For P32 start reading on PDF page 405.

 

[sw34669]

thanks I suspected so, relics from a former time of dumbed down sim . But as a "ascents 101" all on 2 pages it gives a great overview - just the facts (some may be outdated .... ah alternative facts.... kelly anne are you in here ?). Us lesser mortals will feed on any old shite.

I would rather do things by hand manually, you can then appreciate P64 and 65 my word just like my drone autoland.

I'm still trying to see where the checklist should be at in "Apollo 11 - 17 - Before Lunar Liftoff T+124h20min" as it has the same misalignment issue as the before PDI one.

 

[indy91]

Concerning the scenarios, I'm nearly done flying Apollo 10 and creating some mission scenarios. Main reason for flying Apollo 10 (and 8 before that) was replacing a lot of old MCC functions. I'll do the same for Apollo 11 after 10. Good news is checklists will be aligned again then in those new mission scenarios. Bad news is old MCC scenarios will be broken.

 

[sw34669]

well if i can help with anything simpler and possibly time consuming or boring please ask.

I've read through buzzz's notes and he seems to have scribbled cot +10837, the tables next to this show orbits of both crafts and times which are not readable to allow me to work this through . Will the flight plan default of +00777 do (see i did read the flight plan)

 

[indy91]

Hmm, I think you should use +00777. Where exactly is that +10837 number from? I see that value in the transcript as the LM ascent stage weight on the Ascent PAD. Through some conversion magic that +00777 is the same as the 26.6° elevation angle you use in P32-P34, so that should always be valid. I guess this is an item on the CSI Data Card that could theoretically be changed, that's why the checklist doesn't automatically use +00777.

 

[sw34669]

it was on the later pages. On looking at his writing again he scribbled co + 10837 . the co and + looked liked cot (cotangent), it's not, as it's written above orbital comparisons for estimated and actual over 8 orbits. Raumschreiben ? Probably a parker pen, they spent the 1970s advertising on TV that their pens write upside down and in space. I have a copy of the CSI data card printed from one of the telephone book sized manuals.

I have the landing re-designation working now during P64. thx.

 

[indy91]

it was on the later pages.

Later pages of what document? The flown CSI Data Card? I have saved pictures of some of the other data cards when they were up for auction or so, but I don't think I have seen this data card with the notes from the actual mission.

 

[sw34669]

spent a few hours going through that before launch, some strange things. I had to guess where it was in the checklist ~9 mins from ignition but i got close.

Once in the initial orbit, worked through to here and got an op err.
Other things i noticed as i worked through
It has the default time delta as 120h and not 90h . I didnt know if this needs to be changed to 90
The FDAI when put in orbital mode and slew is turned on, doesnt slew, even when in the correct prog to display pitch
I noticed one of the P32 screens for target alt , which seems to have +01090 (about right for target Apa), got over written by +00001
I worked through to the start of the burn but nothing happened and the countdown in R2 stayed at -2
MCC wanted to uplink, but up until the end of the P32 burn there was no checklist uplink, like i've seen in the CSM

 

[Thespacer]

It has the default time delta as 120h and not 90h . I didnt know if this needs to be changed to 90

90 hours is for descent, 120hours is for ascent.

The FDAI when put in orbital mode and slew is turned on, doesnt slew, even when in the correct prog to display pitch

That is strange, as it does ordinarily work. Sounds like a configuration error? Another way to get theta, besides V83, is using 277 in the AGS, assuming it has been correctly initialized.

I noticed one of the P32 screens for target alt , which seems to have +01090 (about right for target Apa), got over written by +00001

P32 does not have target alt. What is the Noun that has that information?

I have not tried your scenario, but I recognise the checklist, which can be a bit tricky if the sequence before was not executed precisely, or it may even be in error. The Opr Err might be because there was no flashing V37. If you tried 20E without such a flashing verb, that would generate an error. The key point at this stage of the flight is that you are transitioning from updating the platform to rendezvous navigation. Before P20 is commenced, the W-matrix is reinitialized to specific values (V67E), the V95 makes sure your SV is not being updated at that moment. After that, you need to enter P20. If the LGC is already in P00, then just do V37E 20E. You wait about a minute for the RR to start doing its thing internally and taking marks, at which point you now want to have the RR start updating the LGC state vector, so you key V80E. Another minute of waiting and you may find a N49 (remember those from P23? They’re back) but the values should be much, much lower (P20 updating of the SV appears to be far more accurate than P23, for NASSP purposes anyway), and that assumes you get a N49 at all, really depends on a few things, you might not see any at all, you might see a few. Anyways, after that, you can get into P32.

I personally find this document most helpful for conducting a successful ascent and rendezvous, for the LM side of the house anyway: https://www.ibiblio.org/apollo/Documents/Mission_G_Rendezvous.pdf (PGNS nominal procedure, 4-3 onwards).

 

[sw34669]

thanks thats really helpful. My issue was trying to lock onto a smaller ghost (reflective) signal and not the real one