The numbers on a pad that relate to pitch and yaw trim get fed to N48. Is there anything else I need to do post SPS burn to trim with thrusters other than nulling out any small dv on the EMS.
First, I think this is still a good primer on the EMS:
http://nassp.sourceforge.net/wiki/Entry_Monitoring_System (disclaimer, haven’t actually read it in a while)
And to make sure we’re on the same page regarding “trim,” it is used in two different contexts: the first is the N48 values for the pitch and yaw settings of the thrust-vectored SPS; the second is when talking about ”trimming“ residuals after a burn. Both are completely separate, in case you were not aware. With that in mind, I do not think there is anything to do after a SPS burn apart from trimming residuals (or as you say, nulling out small dv). I believe you should technically use the numbers on the DSKY (N83 or 85, can’t recall off top of my head), as they are theoretically more accurate than the EMS, which uses its own accelerometer as a back-up mode of counting DV changes. But for NASSP, and for small SPS burns, both EMS and the CMC should be pretty close to each other, in terms of residuals.
is there a small typo on the checklist (MAG instead of MGA)
Indeed that appears to be a typo
it's also not clear here what i need to enter given the first part of setting an SPS P40 burn up. It looks like 5 green digits will be entered into the computer but actually, only 2 get entered, as there are no ABC keys.
That confused me too, initially. This comes down to understanding what V48 - DAP settings - is really about, and even then it’s a bit strange. The first register has 5 ”spaces” (A-E) each of which can be a 1 or 0. The checklist here expects you to know what A will be, depending on whether you have the LM attached etc. B and C relate to how many +X thrusters fire if commanded to translate that way, specifically for ullage. What you put there depends on what the burn requires, and the flight plan will generally state a) if ullage is required, b) how long, and c) whether 2 or 4 jets. If 2, then B and C will be either 1 0, or 0 1. Your pick, depending on which thruster pairs you want to use (generally those with more fuel I guess).11 or 00 will mean 4 jets. D is the deadband (low or max) and directly impacts how tightly the spacecraft will stick to its assigned attitude. Finally, E is the rate it will move under DAP control (I am typing this all from memory, so there may be some inaccuracy but hopefully enough to get you roughly acquainted
1) I filled out 62745 in R1 from the PAD but there is no sign of the LM weight but there is a default in R2 of 33528. The problem is in prev checklists each R1 nd R2 has an ENTER in the checklist so for the one below , before i press PRO on the "Load CSM and LM Weight" checklist item, should I press enter twice 1) to accept R1 and 2 to accept the default thats in R2 before the checklist gets to hitting PRO on the computer.
What I do is this: if I only get a new CSM weight, and not a new LM weight, I will assume the LM weight is still valid, and therefore only change R1 - V21E. That leaves R2 alone. You just Pro from there. V24E means you have to change both, which you do not want to do (unless you remember what was already in R2 before it blanks out).
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