Problem More problems with Apollo 11 MCC

msligo

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I've started Apollo 11 again from the beginning, and everything was going well until MCC-1. MCC progresses successfully from State 24 to State 25 Substate 2, but it doesn't seem to get any further, it just sits there. I therefore never find out whether MCC-1 is go or scrubbed. A few days ago I tested it for well over an hour with no change. I tend to press Option 3 Report State fairly regularly. Could that be messing it up?

I have included two MCC scenario files below. One is from GET 5:31:33, the other from GET 6:24:50.

Code:
MCC_BEGIN
  MCC_GT_Enabled 1
  MCC_MT_Enabled 1
  MCC_padAutoShow 1
  MCC_PCOption_Enabled 0
  MCC_NCOption_Enabled 0
  MCC_scrubbed 0
  MCC_MissionType 7
  MCC_MissionPhase 3
  MCC_MissionState 23
  MCC_SubState 3
  MCC_EarthRev 3
  MCC_MoonRev 0
  MCC_AbortMode 0
  MCC_StateTime 4291.521241900014
  MCC_SubStateTime 4171.373520900055
  MCC_MoonRevTime 34293.020513799049
  MCC_padNumber 8
  MCC_AP11MNV_Att 0.221870389950 212.211839064924 357.277636239431
  MCC_AP11MNV_BSSStar 0
  MCC_AP11MNV_burntime 2.903150942010
  MCC_AP11MNV_dV 5.100000000000 0.000000000000 19.000000000000
  MCC_AP11MNV_GDCangles 110.947400675177 127.128317032194 333.244456188009
  MCC_AP11MNV_GET05G 0.000000000000
  MCC_AP11MNV_GETI 17035.031928936951
  MCC_AP11MNV_HA 9999.900000000000
  MCC_AP11MNV_HP 119.811066853470
  MCC_AP11MNV_lat 0.000000000000
  MCC_AP11MNV_lng 0.000000000000
  MCC_AP11MNV_PropGuid SPS/G&N
  MCC_AP11MNV_pTrim 0.646677803612
  MCC_AP11MNV_purpose Evasive
  MCC_AP11MNV_remarks 
  MCC_AP11MNV_RTGO 0.000000000000
  MCC_AP11MNV_SetStars Vega, Deneb
  MCC_AP11MNV_Shaft 98.755986800504
  MCC_AP11MNV_SPA 0.000000000000
  MCC_AP11MNV_Star 2
  MCC_AP11MNV_SXP 0.000000000000
  MCC_AP11MNV_Trun 22.746335808129
  MCC_AP11MNV_Vc 19.664476438551
  MCC_AP11MNV_VI0 0.000000000000
  MCC_AP11MNV_Vt 19.672569735548
  MCC_AP11MNV_Weight 63656.268410915342
  MCC_AP11MNV_yTrim -0.285618660490
MCC_END
RTCC_BEGIN
  RTCC_REFSMMATType 0
  RTCC_P30TIG 10094.712615874596
  RTCC_SplLat 0.000000000000
  RTCC_SplLng 0.000000000000
  RTCC_TEI 0.000000000000
  RTCC_EI 0.000000000000
  RTCC_TLI 10435.031928936951
  RTCC_LOI 273215.000000000000
  RTCC_SEP 0.000000000000
  RTCC_DOI 0.000000000000
  RTCC_PDI 0.000000000000
  RTCC_TLAND 370031.000000000000
  RTCC_LSAlt -3073.263000000000
  RTCC_LSAzi -1.588249619000
  RTCC_LSLat 0.012459711400
  RTCC_LSLng 0.413778779200
  RTCC_LunarLiftoff 0.000000000000
  RTCC_Insertion 0.000000000000
  RTCC_Phasing 0.000000000000
  RTCC_CSI 0.000000000000
  RTCC_CDH 0.000000000000
  RTCC_TPI 0.000000000000
  RTCC_alt_node 0.000000000000
  RTCC_GET_node 0.000000000000
  RTCC_lat_node 0.000000000000
  RTCC_lng_node 0.000000000000
  RTCC_TEPHEM 40418.561184143517
  RTCC_PericynthionLatitude 0.004870760200
  RTCC_TIGSTORE1 0.000000000000
  RTCC_DVLVLH 3187.955656781137 0.000000000000 0.000000000000
  RTCC_R_TLI 6367501.394059641287 2007667.202660728246 367397.687360955111
  RTCC_V_TLI -2018.826275508659 10565.209234017562 1444.946330254249
  RTCC_DVSTORE1 0.000000000000 0.000000000000 0.000000000000
  RTCC_StoredREFSMMAT 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000
  RTCC_SVSTORE1 None 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000
RTCC_END
END

Code:
MCC_BEGIN
  MCC_GT_Enabled 1
  MCC_MT_Enabled 1
  MCC_padAutoShow 1
  MCC_PCOption_Enabled 0
  MCC_NCOption_Enabled 0
  MCC_scrubbed 0
  MCC_MissionType 7
  MCC_MissionPhase 3
  MCC_MissionState 25
  MCC_SubState 2
  MCC_EarthRev 3
  MCC_MoonRev 0
  MCC_AbortMode 0
  MCC_StateTime 889.579724299999
  MCC_SubStateTime 885.808506299999
  MCC_MoonRevTime 37490.978075999512
  MCC_padNumber 7
  MCC_P37PAD_dVT[0] 4848.615378676197
  MCC_P37PAD_GET400K[0] 177743.843312988174
  MCC_P37PAD_GETI[0] 49715.031928936951
  MCC_P37PAD_lng[0] -165.000000000000
  MCC_P37PAD_dVT[1] 0.000000000000
  MCC_P37PAD_GET400K[1] 0.000000000000
  MCC_P37PAD_GETI[1] 0.000000000000
  MCC_P37PAD_lng[1] 0.000000000000
  MCC_P37PAD_dVT[2] 0.000000000000
  MCC_P37PAD_GET400K[2] 0.000000000000
  MCC_P37PAD_GETI[2] 0.000000000000
  MCC_P37PAD_lng[2] 0.000000000000
  MCC_P37PAD_dVT[3] 0.000000000000
  MCC_P37PAD_GET400K[3] 0.000000000000
  MCC_P37PAD_GETI[3] 0.000000000000
  MCC_P37PAD_lng[3] 0.000000000000
MCC_END
RTCC_BEGIN
  RTCC_REFSMMATType 0
  RTCC_P30TIG 42510.557397931923
  RTCC_SplLat 0.000000000000
  RTCC_SplLng 0.000000000000
  RTCC_TEI 0.000000000000
  RTCC_EI 0.000000000000
  RTCC_TLI 10435.031928936951
  RTCC_LOI 273560.251616011374
  RTCC_SEP 0.000000000000
  RTCC_DOI 0.000000000000
  RTCC_PDI 0.000000000000
  RTCC_TLAND 370031.000000000000
  RTCC_LSAlt -3073.263000000000
  RTCC_LSAzi -1.588249619000
  RTCC_LSLat 0.012459711400
  RTCC_LSLng 0.413778779200
  RTCC_LunarLiftoff 0.000000000000
  RTCC_Insertion 0.000000000000
  RTCC_Phasing 0.000000000000
  RTCC_CSI 0.000000000000
  RTCC_CDH 0.000000000000
  RTCC_TPI 0.000000000000
  RTCC_alt_node 114528.298651971621
  RTCC_GET_node 273560.238247923553
  RTCC_lat_node 0.003604527838
  RTCC_lng_node 3.024658899438
  RTCC_TEPHEM 40418.561184143517
  RTCC_PericynthionLatitude 0.004870760200
  RTCC_TIGSTORE1 0.000000000000
  RTCC_DVLVLH 13.024057629294 -0.070712953896 13.341328675557
  RTCC_R_TLI 6367501.394059641287 2007667.202660728246 367397.687360955111
  RTCC_V_TLI -2018.826275508659 10565.209234017562 1444.946330254249
  RTCC_DVSTORE1 0.000000000000 0.000000000000 0.000000000000
  RTCC_StoredREFSMMAT 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000
  RTCC_SVSTORE1 None 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000 0.000000000000
RTCC_END
END
 
Last edited:

indy91

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I tend to press Option 3 Report State fairly regularly. Could that be messing it up?

No.

What I find strange in your MCC state is this:

Code:
MCC_scrubbed 0

That can only mean that MCC-1 is not scrubbed. In which case it wouldn't tell you that MCC-1 gets scrubbed, there is no message for "MCC-1 has to be done". So it is skipping the early PTC REFSMMAT uplink and is waiting for a longer time to the next event than in the MCC-1 being scrubbed case. The actual MCC-1 update will happen at about 9:50h GET, so you maybe didn't wait for that long.

But MCC-1 really should have been scrubbed. TLI must have gone quite wrong, if it isn't scrubbed. Can you try to manually calculate a MCC-1? Open the RTCC MFD go to Maneuver Targeting and then Translunar. Then press the MAN button once so that it shows the TLMCC Option 2. Then press TIG and enter 12:00:00, which is the approximate MCC-1 TIG. Then press CLC. What does it give you for the total DV of MCC-1? It's the number on the lower right, below DVX, DVY and DVZ.

MCC-1 gets scrubbed when the DV is below 50 ft/s, a usual value is 10-15 ft/s. If it is below 50 ft/s then something else is buggy in the MCC.
 

msligo

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Ok, the number is +61.3, so that probably explains it. Perhaps the SPS burn to avoid the S-IVB didn't go well? I think there might be a mistake in the DAP settings for that burn, the RCS rotates the spacecraft so slowly that I just can't keep up with the timings, and I always mess up the burn.

There's a blue checklist item however which says MCC-1 (Click Pro or Fail if Scrubbed). Wouldn't it be a good idea to provide some indication when it's not scrubbed, so the pilot knows to click Pro?
 

indy91

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Ok, the number is +61.3, so that probably explains it. Perhaps the SPS burn to avoid the S-IVB didn't go well? I think there might be a mistake in the DAP settings for that burn, the RCS rotates the spacecraft so slowly that I just can't keep up with the timings, and I always mess up the burn.

You mean the attitude rate is too slow for it to reach the desired burn attitude? Or do you mean a DAP problem during the burn? If you aren't in burn attitude and are burning it anyway then yes, that could explain the large MCC-1 DV. TLI is biased to account for (most of) the evasive maneuver, which is done against the approximate thrust direction of TLI. Looks like the timing is quite tight, but it should be doable. Half an hour between LM ejection and the evasive maneuver, and P40 is started 15 minutes before the burn.

Here something interesting. This is the flown page of the Apollo 11 launch checklist for this part: https://airandspace.si.edu/sites/de...objects/record-images/NASM-NASM2013-02660.jpg That's one of the few launch checklist pages we have pictures of for this mission. Very faintly in the lower right I see some handwritten notes that seem relevant to this issue. If I read it right it says "Load N22 SPS ATT" and some other things associated with that. This would suggest that they started the maneuver to the evasive burn attitude right after LM ejection, which probably makes sense if it is a larger attitude maneuver. So maybe we need to improve the NASSP checklist with those handwritten notes!

There's a blue checklist item however which says MCC-1 (Click Pro or Fail if Scrubbed). Wouldn't it be a good idea to provide some indication when it's not scrubbed, so the pilot knows to click Pro?

Yeah, I think that makes sense. For all the other midcourse corrections it has no preliminary calculation, so it either displays the Maneuver PAD (which should serve as an indication that the burn has to be done) or the same "maneuver was scrubbed" message gets displayed.
 

msligo

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Wow, that's really cool. So, the SPS Evasive Maneuver checklist has the following section:

SPS Evasive Attitude

V49E
V25E
Load SPS PAD Burn Attitude
CMC Mode - AUTO
PRO
PRO
F 50 18
ENTER
T-10:00


So, it looks like I need to start the attitude maneuver, wait for it to reach the correct attitude, press ENTER, and all of this should happen before T-10:00. The DAP options however have R1 at 21111, and I think that 5th digit means that the rotation rate is only 0.2 deg/s. As a result, by the time the maneuver has finished, the burn countdown timer is usually already down to around T-6:00, and then I have to rush through the checklist items to try to catch up. I usually fail to catch up before T-0:00 though.


Looking at that picture, it actually looks like they've crossed out the DAP R1 value and replaced it with 21101! That wouldn't fix the slow rotation rate, but it changes the deadband to 0.5 deg. Would that solve the problem?
 
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