NASSP Apollo 8 MCC3 Scrubbed?

Wedge313

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At T+46:09:29 the checklist expects to either receive a PAD for MCC3 or a message saying its scrubbed. I'm at 47:15 and haven't heard from mission control. I know I got a message that MCC1 was scrubbed, and an uplink for MCC2, but crickets so far on MCC3. Where have I gone wrong? Thanks.
 

indy91

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Can you post your scenario at that time? Normally I wouldn't be worried about a bit of a delay in messages from the MCC. They often don't come up at a specific GET but rather at a time relative to some event. The MCC-3 update should happen at 23 hours before LOI. 47:15 is definitely too late for that.
 

Wedge313

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I'm thinking about changing the name of the CSM to "Jupiter 2" because I think I'm Lost in Space. MCC1 was scrubbed, MCC2 was only 7.1 fps, at that point I had a warm fuzzy feeling. The P21 at T+34:41 had me at -0406.5 Alt, which didn't seem too far out of the ballpark and correctable. All P52s have gone well, 00001s (which I guess means the ship knows where it is, but doesn't mean it's where it's supposed to be). But the P23s using the Moon's horizon seemed off, mainly because I am looking at the dark side of the moon, only an extremely thin fingernail of illuminated surface visible in the sextant, so half of the sightings were undo-able. The TLI+44 PAD (not sure what that's for) had a DVC value of 6058.2 which seemed high for just about anything. So the missing MCC3 PAD/uplink makes me think mission control knows I'm so far off course that I'm doomed, but they don't have the heart to tell me. I'm thinking about Richard Crenna's character in "Marooned". Thanks for your assistance.
 

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Wedge313

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Out of curiosity I opened up Interplanetary MFD, and it looks like I could get to the moon in 24.5 hours with about a 72 m/s dV burn (which I did manually just for fun, about a 28 sec. burn). I then fast forwarded until I was about 20 hours out (according to IMFD) and still no MCC3 PAD. But by now I'm probably so far off that the normal event sequence has been tossed out. I'll go back to just before the first MCC and see if I gummed something up. I may also let this IMFD/manual burn scenario play out and see where I end up.
 

indy91

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The TLI+44 PAD is for a direct return abort back to Earth, without flying past the Moon. They are meant to return you as quickly as possible, spending most of the nearly 10000 ft/s of Delta V your CSM has. Looking at the transcript, the real Apollo 8 mission had a DV of 6070.1 ft/s on their Maneuver PAD. So you are right on! You can of course ignore these PADs, unless you intend to skip going to the Moon.

So from your previous Orbiter log file I know you are using the May 13, 2020 release of NASSP. I could switch to that release version to try your scenario, but I think I know what is going on already. Don't update the NASSP version in mid flight though, there have been many MCC updates and your scenario would definitely be broken then.

I think your NASSP version was in a time window (from mid 2019 when I last flew Apollo 8 until I fixed it a few weeks ago) where the timing of the MCC-3 update was wrong. It comes at 18 hours before LOI instead of 23 hours before LOI. So I think everything is going fine in your mission, it's just the one update from mission control that comes too late.

You can cause the update to happen through the debug menu though. So wait until you think you should be getting the MCC-3 update (about 46:15h GET) then open the CAPCOM menu of the MCC, press 9 for "Debug Options" and then press 4 for "Inc State". That should make it switch to the next MCC state, which is the MCC-3 update. And very likely you will get the "MCC-3 is scrubbed" message then.

So just a small bug in that NASSP version hopefully and no issue with your trajectory.
 

Wedge313

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Excellent! As you predicted, after following your steps with the MCC debug, MCC3 was scrubbed. So on we trudge. Thanks for your help.
 
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