Apollo 8 run ruined or not?

[Adam106]

I'm currently doing a full run through of Apollo 8, but I'm not sure if at approx 44 hours it's gone wrong somehow.....

TLI seemed good and I was happy, MCC-1 was scrubbed, but MCC-2 had a dv of 1507.7...which seems huge...is it? MCC-3 scrubbed, and most of my P21's are getting a hanging COMP ACTIVITY and not doing anything. The only way to clear is a V96E. This is with a fresh state vector unlinked using Project Apollo MFD.

I'm worried about the huge MCC-2 but don't know if it can be saved, or why it was even that big. Should I continue?

 

[STS]

Could you provide an scenario (quicksave) of the run so that Houston (the dev guys) can analise it?

 

[Adam106]

Yeah, that would help.

 

[rcflyinghokie]

If you have any earlier scenarios (pre MCC-2) those would help. That MCC2 DV you received is way too high.

Also which NASSP version are you running?

 

[indy91]

Hmm, that scenario doesn't look good. The MCC-2 burn was not a good one it seems. Do you also have a scenario from before you got the message that MCC-1 got scrubbed? Maybe I can retrace the steps then and figure out if the problem is TLI, or the MCC-1 calculation, or the MCC-2 calculation etc.

 

[Adam106]

Thanks, I've got a couple of saves here. One from about the 4 hour mark (Post TLI) and one from 11 ish hours. I'm on the latest version of NASSP-1684 and 2016 Beta.

 

[indy91]

Ah sorry, my bad, it was a MCC bug that only happens when MCC-1 gets scrubbed. That happens if the DV is smaller than 5.0 ft/s, in your case MCC-1 would have been 3.7 ft/s. The MCC-2 calculation was relying on some numbers from the MCC-1 calculation, but those numbers were only saved if MCC-1 isn't getting scrubbed. So that made it impossible that the MCC-2 calculation is giving anything useful. This will be fixed very soon.

The best way to recover is probably some scenario before the MCC-2 calculation. I can do a quick scenario edit for you, if you want. Should I use your Save 2 or do you have a later one that is still before MCC-2 is getting calculated?

 

[Adam106]

Ah, thanks for looking. Yep can you use my 'Save 2', it's the best one I could find I think. Cheers.

It's nice to know that I didn't make a major mistake at least. Bit bummed that I have to redo 30 ish hours of the flight, but all's good. Just when I thought I'd mastered P23s, more practice.

Out of interest, is there an easy way to tell if TLI and/or the MCC's have gone to plan? I'd prefer not to use things like IMFD and other 'gamey' orbiter methods. The RTCC MFD still looks very intimidating to me.

 

[indy91]

Here is the fixed Save 2 file. Expect a 5.4 ft/s MCC-2. I basically just did what the MCC will do automatically once the fix is in NASSP, copy over some numbers from one place to another.

Sorry for the loss of time in the mission. At least you found a bug that I could now fix so, uhh, thanks for your contribution to NASSP!

The best way to see if maneuvers have gone well is probably the Delta V of the next maneuver, provided there are no bugs of course. MCC-1 got scrubbed because it's DV was very small, so that is a sign that TLI went very well. You will likely get no MCC-3 at all if MCC-2 goes well and MCC-4 should also be small. There are some ways to check e.g. the closest approach of your spacecraft to the Moon with the RTCC MFD, but that part of the MFD is very difficult to use and still experimental. Using some MFD pages that look exactly the same as MOCR screens would have.

 

[Adam106]

Thanks again. I’ll give it a go.

Is the bug likely to be present in a Apollo 11 scenario? Or will the update be out very soon? That will be my next challenge.

 

[indy91]

It's funny, that exact same bug was already fixed before for Apollo 10 and 11, but for some reason I didn't think of checking if it also happens on 8. So no, won't happen for those missions!