Q1) in A7 or A8 when a maneuver is approaching I got the uplink message to update the state vector and so far so good, the question is: suppose that before to make the maneuver or before making a P22 or P23 sighting task I want to upload again a fresh SV (not historically correct but for the sake of a simulation session a possible action to perform) in this case I cannot get another uplink from the ground with MCC (isn't it? or is there a way in the COMM menu to ask MCC to upload again a new SV at any time in the mission if I request it?)
Unfortunately you can't request a fresh state vector from the MCC. It can only repeat the last uplink (of any type) it did. But that seems like a useful feature, maybe I'll implement that some time.
so I can get a SV from ApolloMD or RTCC MFD ... the question is: is the SV (which are the position and velocity components of the spacecraft) dependent on the reference system used at that time in the mission?
Yes, the AGC either keeps a Earth or a Moon referenced state vector. The uplinked state vectors will be in the reference system you are currently in. But it wouldn't matter if it was the wrong reference system, as one of the uplinked numbers with the state vector is the ID of the reference system (-2 = LM moon-centered, -1 = LM earth centered, 1 = CSM earth-centered, 2 = CSM moon-centered) of that uplinked state vector. So the AGC would be able to convert it. Basically, you don't need to worry about the reference, the MFDs and and the AGC are handling it.
-> as Indy91 said, before to try to get a PAD mnvr solution using RTCC I should download the REFSMMAT being used to the RTCC MFD as by default it retains the launch configuration...is it necessary to download it also before to ask for a SV updated? and what about if I ask for a SV update using ProjectApolloMFD?) ... which the best correct procedure to get a "fresh" SV update at any time ?
Both the Project Apollo MFD and the RTCC MFD are fine to use for state vector updates. The PAMFD might be a bit simpler for this, the RTCC MFD gives you more options.
Q2) in Apollo8, after CSM/LV separation in the checklist for the evasive maneuver it is said "mnvr to local vertical (+X towards Erath) maintaining SIVB in CDR window - thrust -X (away from Earth) -1.5 fps) ..... not clear what I am supposed to do. I can see the SIVB in front of me looking from the rendezvous window on the left (CDR window) keeping it in the center of the crosshair of the COAS...but the X axis is not directed radially toward the Earth .... if I rotate the craft X axis to point the Earth I can see the Earth centered in the COAS but the SIVB is less than 90 degree on the right/left of me so to speak...so how can i see it through the "CDR window" if now I am pointing the center of the Earth? what I am doing wrong? in which attitude I should be to start the evasive maneuver?
You point the CSM at the Earth and then roll it so that you can still see the S-IVB, so the windows pointing in the direction of the S-IVB. A bit hard to see from the 2D cockpit windows, so the important part is that you are pointing the pointy end of the CSM directly at the Earth
Q3) I tried P22 in Apollo 7 and I managed to do/understand it partially, maybe a deep question will come later, but for P23 I am still puzzled; I look around in the forum and I saw some treats about P23 mostly for Apollo8, so for a moment I decided to stop doing P23 on Apollo7 and try to do it on Apollo8 until I don't fully understand it...indeed sometime I got deltaR and deltaV less than 50...so it gave me hope, but there is something that I would like to understand:
what does it means "reinitialize the cislunar W-matrix"? I "loosely" understood that this matrix is a kind of "error matrix" between real position/velocity vectors in the AGC and the ones deduced by making a marking sequence....so the target to get deltaR and deltaV as close as possible to zero to minimize the error --- if it is so, why do we need to "reinitialize it" before to make measurements? clearly it looks to me that this W matrix is not just and error matrix of the type "Error"="SV by marking sequence" - "SV onboard of the AGC" ... so it also means that the deltaR and deltaV values in N49 are NOT the components of the W matrix (after all it should be a 3x3 matrix so it should have 9 components) .... so what does it represent? and why at some point in the check list it is stated that it is reinitialized to the launch pad values (V67E R1+00094, R2+00057, R3+0003) and than there is V93E... what these numbers in R1, R2, R3 means? and where are they come from? if with V67E i can set some numbers into the W matrix, when I do V93E to "reinitialize" it what's happen inside the W matrix? all components set to zero?
P23 on the actual Apollo 7 mission did not work well at all. It's included in the checklists for historical accuracy, but you won't get any good results. That technique just doesn't work well in Low Earth Orbit.
Some good explanations for this can be found in the original MIT documentation, for example here:
https://www.ibiblio.org/apollo/NARA-SW/R-577-sec5-rev4-start-5.2.pdf PDF pages 43+.
For the astronaut relevant is this:
-When you use V67 it calculates the current position and velocity error estimate and displays them as R1 and R2 in N99.
-But the main function of V67 is to change the re-initialization parameters for the W-Matrix. This doesn't change the W-Matrix itself, just those parameters.
-V93 recalculates the W-Matrix using those re-initialization parameters. Essentially that resets the current error estimate of the state vector.
-When you then do marks with P20, P22 or P23 the W-Matrix will change with each incorporated mark, usually (and hopefully) trending towards smaller errors.
