I'm running the Apollo 8 mission, at about 60:42, getting ready for MCC4. The maneuver only requires a dV of 2.2, so we'll be using the RCS. Question: in the checklists for both P30 and P41 it directs me to "set DET". What do I set it to? Thanks.
You can use the event timer to count down to TIG, but when the event timer counts down, it won't cycle from 00:00 back to 59:59. Counting up allows you to monitor burn time as well. This becomes more important when performing DPS burns under manual throttle. Another benefit of setting the DET to count up is that it allows you to 'count past' 59:59 when your TIG is over an hour away.Good explanation, thank you. So it's not used as a countdown clock. If the Tig is 40 min, I set the DET to 20 min and let it count up, so that at Tig it would read 00:00 and then continue counting up so I can monitor the burn time, same as we did for the TLI burn. Thanks.
I've encountered similar numbers when running P30 for LOI and the predicted Pe comes back negative.As far as the residuals, I don't think I have that figured out. If after the burn the three registries show 00000, 00002, 00000 I should tweak the pitch, correct? But when I tweaked the pitch, the roll and yaw error jumped up. After a few minutes of flailing I settled in on 00001, 00002, 00001, and wish I hadn't messed with the original. Any tips? Also, the P21 ground track shows my ALT at -0221.2. Seems to me that MCC4 should have tried to prevent me from impacting the moon. Am I going to get another chance to correct this, or at least will they name the crater after me? Thanks
I've encountered similar numbers when running P30 for LOI and the predicted Pe comes back negative.
I'm not exactly sure what causes this, although my hypothesis is that the SV is referencing Earth SOI (and therefore Earth Pe). The LOI burn does bring me into the correct orbit.
N42 values of ha and hp (in P30) are preburn predictions and will vary slightly from N44 values (post-burn estimates). N42 assumes the DV will be burned impulsively. The larger the DV the greater the error in N42. Recognition: Difference in displays.
072:51:24 McCandless: ... 0169.2, plus 00610 ... The values which you would see on Noun 42 prior to LOI burn are HA, plus 431.3; HP, minus 128.2. Read back, over.