I'm to about 2 hours into the Apollo 7 mission and I'm performing the P52 IMU Realign checklist.
Does anyone have any general tips for this procedure? I'm guessing that this is something that I'll get better at with some practice, but it's been difficult to get a good mark as the star moves across the sextant very quickly. Maybe slow the time down during this procedure until I get better at it.
How close to the center does the mark have to be to prevent problems later on? Can I use the Mark Reject button if I have a bad mark? If so do you just manually rerun through the P52 steps until you catch back up to the current spot on the checklist?
Finally (and my biggest issue) the 2nd mark specifies to use star #41. But by the time I get to the V06 N92 point in the checklist for the 2nd mark, the trunnion angle on R2 is around 48 degrees and increasing over time. If I'm understanding everything correctly, the trunnion angle has a maximum angle of 49.775 degrees. Which doesn't allow me enough time to get the star centered and a mark taken before it exceeds 49.775 degrees. Would that mean that I would have to rotate the entire S-IVB & CSM stack to get a mark? That doesn't seem like that is what would have happened in the real Apollo 7 mission for this particular IMU realign?
Does anyone have any general tips for this procedure? I'm guessing that this is something that I'll get better at with some practice, but it's been difficult to get a good mark as the star moves across the sextant very quickly. Maybe slow the time down during this procedure until I get better at it.
How close to the center does the mark have to be to prevent problems later on? Can I use the Mark Reject button if I have a bad mark? If so do you just manually rerun through the P52 steps until you catch back up to the current spot on the checklist?
Finally (and my biggest issue) the 2nd mark specifies to use star #41. But by the time I get to the V06 N92 point in the checklist for the 2nd mark, the trunnion angle on R2 is around 48 degrees and increasing over time. If I'm understanding everything correctly, the trunnion angle has a maximum angle of 49.775 degrees. Which doesn't allow me enough time to get the star centered and a mark taken before it exceeds 49.775 degrees. Would that mean that I would have to rotate the entire S-IVB & CSM stack to get a mark? That doesn't seem like that is what would have happened in the real Apollo 7 mission for this particular IMU realign?