Apollo 13 Launch Scenario: What should I expect?

[rcflyinghokie]

On we go to the LM-CSM Power Transfer procedure. After going through the steps I don't show any amps or volts on the BAT charger. Is this modeled in the simulation, or just another procedural error on my part?

As I mentioned previously, we currently don't have a model for reverse power flow, so you cannot charge the CM bats using the LM power. You will have to manually edit the scenario to top them off.

 

[Wedge313]

I've got another snag, this with the LM alignment.

At around 133:22 they decide to power up the LM, followed by an alignment. I've followed the now twice-modified 30-min Activation Checklist, maneuvered to the burn attitude (Earth in the LM COAS, sun is up in the AOS). I did the DEDA 400+5 and the V41N20, and the AGS and PGNS attitudes match on the FDAI. I think I'm squared away to this point.

Then they uplink the LM state vector, followed by what looks like (on the modified flight plan) two REFSMMATs. And then they do (I think) a P52 option 1 using the sun and moon.

1. If they are uplinking two REFSMMATs, I assume it's an Actual and a Desired?
2. What REFSMMAT(s) do they uplink? PTC? Lunar Entry? The Flight Director's log says "Burn REFSMMAT", Is this a P30 REFSMMAT? I think this is where I'm messing up.
3. When the P52 option 1 alignment is done, don't we want the PGNS and AGS attitudes to still be close? It seems like the MCC-7 burn was still very close to having the Earth's terminator in the COAS.

I've tried various REFSMMATs, and as a check I ran a P52 option 3 to see if the LGC knows where it is, and I'm not close.

Thanks

 

[rcflyinghokie]

1. If they are uplinking two REFSMMATs, I assume it's an Actual and a Desired?

Correct, I will elaborate in the next answer.

2. What REFSMMAT(s) do they uplink? PTC? Lunar Entry? The Flight Director's log says "Burn REFSMMAT", Is this a P30 REFSMMAT? I think this is where I'm messing up.

The first one is an actual REFSMMAT based on the known alignment of the spacecraft (the one AGS is body axis aligned to) where the sun and earth were in the AOT. Then the desired REFSMMAT was a P30 REFSMMAT for MCC-7 burn.

3. When the P52 option 1 alignment is done, don't we want the PGNS and AGS attitudes to still be close? It seems like the MCC-7 burn was still very close to having the Earth's terminator in the COAS.

A 400+3 was performed to align the AGS to PGNS.

 

[Wedge313]

I'm still not getting this.

The first one is an actual REFSMMAT based on the known alignment of the spacecraft (the one AGS is body axis aligned to) where the sun and earth were in the AOT.

To generate this, do I use the "REF from ATT" option in the RTCC REFSMMAT? And then uplink it as the Actual REFSMMAT?

Then the desired REFSMMAT was a P30 REFSMMAT for MCC-7 burn.

I calculated the MCC maneuver, created the PAD, and generated a P30 REFSMMAT. I uplinked this as a Desired REFSMMAT.

Then I did the P52 option 1 using the sun and moon.

(Disclaimer, initially I only showed a required dV of 0.17 fps, so I decided to change the trajectory a little to create the need for a midcourse correction. I did that before I started any of the REFSMMAT or MCC calculations. I shallowed until I needed about 2.7 fps to get back in the corridor.)

Now after the P52, I'm trying to check the alignment by running a P52 option 3, and I manually selected a star near the center of the AOS. When the F 50 18 shows up I let the ship auto maneuver (PGNS as guidance) expecting it to try to center the star in the AOS. Instead it starts to maneuver away from my selected star, so the alignment can't be correct.

EDIT: I've been playing around with this all morning, and I think found what's wrong? The LGC had no idea what time it was. I set the time in the LGC, and all seems to be working. I'd guess without a time, the LGC couldn't know where to look for stars or planets. After the alignment I ran a P52 option 3, and the LM maneuvered almost exactly to the star I had picked.

Continuing to experiment I uplinked the P30 Ext DV, started P41 and let the LM auto maneuver to the MCC burn attitude. The pitch and roll were almost perfect (000, 000) but for some reason the yaw was 296 (I don't think the yaw really affects the burn?). I manually yawed to 000 and the earth is in the COAS, not centered but I think close enough for government work.

Looking at the 30 Minute Activation checklist it looks like they deleted the LGC clock set on page 32, and I don't see where they ever put it back in? Isn't that required?

 

[rcflyinghokie]

I'm still not getting this.


To generate this, do I use the "REF from ATT" option in the RTCC REFSMMAT? And then uplink it as the Actual REFSMMAT?


I calculated the MCC maneuver, created the PAD, and generated a P30 REFSMMAT. I uplinked this as a Desired REFSMMAT.

Then I did the P52 option 1 using the sun and moon.

(Disclaimer, initially I only showed a required dV of 0.17 fps, so I decided to change the trajectory a little to create the need for a midcourse correction. I did that before I started any of the REFSMMAT or MCC calculations. I shallowed until I needed about 2.7 fps to get back in the corridor.)

Now after the P52, I'm trying to check the alignment by running a P52 option 3, and I manually selected a star near the center of the AOS. When the F 50 18 shows up I let the ship auto maneuver (PGNS as guidance) expecting it to try to center the star in the AOS. Instead it starts to maneuver away from my selected star, so the alignment can't be correct.

EDIT: I've been playing around with this all morning, and I think found what's wrong? The LGC had no idea what time it was. I set the time in the LGC, and all seems to be working. I'd guess without a time, the LGC couldn't know where to look for stars or planets. After the alignment I ran a P52 option 3, and the LM maneuvered almost exactly to the star I had picked.

Continuing to experiment I uplinked the P30 Ext DV, started P41 and let the LM auto maneuver to the MCC burn attitude. The pitch and roll were almost perfect (000, 000) but for some reason the yaw was 296 (I don't think the yaw really affects the burn?). I manually yawed to 000 and the earth is in the COAS, not centered but I think close enough for government work.

Looking at the 30 Minute Activation checklist it looks like they deleted the LGC clock set on page 32, and I don't see where they ever put it back in? Isn't that required?

I am looking into the clock now, I will report back.

Also, regarding the checklist with the quad heater cb randomly in, it actually was correct due to it breaking before launch:

135:35:20 Haise: And, Jack, you can tell Owen Morris that the RCS System A/B 2 Quad 1 breaker is still nicely in.
135:35:52 Lousma: Roger. We'll pass the word.
Comm break.
One of RCS breakers was broken before launch. The permanently closed circuit breaker is still, indeed, closed.

 

[Wedge313]

Also, regarding the checklist with the quad heater cb randomly in, it actually was correct due to it breaking before launch:

Haha yeah I just got to that point reading through the Apollo Flight Journal, and thought that was probably the case. Thanks.

 

[rcflyinghokie]

Looking at the 30 Minute Activation checklist it looks like they deleted the LGC clock set on page 32, and I don't see where they ever put it back in? Isn't that required?

I think the clock is stopped on the LGC when the cb is pulled, but I am not 100% sure. However, looking through the mission control transcripts, during the uplink of the REFSMMAT's and SV, they mention in passing "we have a good clock update" so that might indicate a clock update was shipped up as well. Again I am still looking into this to be sure.

 

[Wedge313]

The Flight Director Log at 134:31 says "Good clock update" so maybe that's the case. I remember at some point earlier using the RTCC to uplink the LGC clock time. It might have been in all the stuff they uplinked and I missed it.

 

[rcflyinghokie]

The Flight Director Log at 134:31 says "Good clock update" so maybe that's the case. I remember at some point earlier using the RTCC to uplink the LGC clock time. It might have been in all the stuff they uplinked and I missed it.

Yeah they didnt mention it to the crew, so I am guessing its implicit. So i would ship up a clock update with your state vector and REFSMMATs

 

[Wedge313]

Found where they (we) uplinked the LGC time...

059:11:47 Lousma: Aquarius, Houston. I think we've got a better way of getting your mission time up.
059:11:56 Lovell: Go ahead with it.
059:11:59 Lousma: Okay. We can do a Verb 55, Enter, and then put an R1, minus 00088. In R2, minus 00059; R3 minus 03274.
(Verb 55 (increment LGC time) gives Mission Control access to the computer's internal clock).

I don't know if that V55 is a set-it-and-forget-it thing that allowed them to uplink the LGC time update from then on?

 

[rcflyinghokie]

Found where they (we) uplinked the LGC time...

059:11:47 Lousma: Aquarius, Houston. I think we've got a better way of getting your mission time up.
059:11:56 Lovell: Go ahead with it.
059:11:59 Lousma: Okay. We can do a Verb 55, Enter, and then put an R1, minus 00088. In R2, minus 00059; R3 minus 03274.
(Verb 55 (increment LGC time) gives Mission Control access to the computer's internal clock).

I don't know if that V55 is a set-it-and-forget-it thing that allowed them to uplink the LGC time update from then on?

V55 has nothing to do with MCC access to the clock, so that comment is incorrect. V55 simply changes the current time by incrementing it to null any error between its current time and expected (correct) time. This was done because they couldn't uplink, but they could see the current LGC time and generated deltas.

Similar to a V42, which allows inputting error between the IMU angles and correct angles, and it nulls the errors out.

 

[Wedge313]

OK I think I follow you....there was some (incorrect) time already stuck in the LGC that they could see, and they just had the crew input the delta so the time was correct (it was 88 hours, 59 minutes, and 32.74 seconds off)?

I learn so much on this forum

 

[rcflyinghokie]

OK I think I follow you....there was some (incorrect) time already stuck in the LGC that they could see, and they just had the crew input the delta so the time was correct (it was 88 hours, 59 minutes, and 32.74 seconds off)?

I learn so much on this forum

Yeah pretty much I dont remember if a "start time" of sorts was padloaded, but a fresh LGC start even under normal circumstances had a useless time, so it would be set via the CMC (and then a V55 used to correct the initial error by pressing enter on both at the same time on N65)

 

[Wedge313]

At EI -6+30, starting the CM power up. On the RCS pre-heat I don't get any voltage indications on panel 101. Before I run through checking my baseline configuration and re-doing the power up procedure a third time, I wanted to check if this is just a quirk with the simulated panel 101 display? Or did I miss something in the thousands of procedure changes over the last few flight days?

 

[rcflyinghokie]

At EI -6+30, starting the CM power up. On the RCS pre-heat I don't get any voltage indications on panel 101. Before I run through checking my baseline configuration and re-doing the power up procedure a third time, I wanted to check if this is just a quirk with the simulated panel 101 display? Or did I miss something in the thousands of procedure changes over the last few flight days?

5C-D and 6A-D? The test meter should work for those 6 injector temps, are you getting it to work for any other indications?

 

[Wedge313]

No, no indications at all. I'll review my baseline configuration again. If that doesn't fix it I'll read through the power up procedures again. Probably one switch or c/b (or more) I missed.

 

[rcflyinghokie]

No, no indications at all. I'll review my baseline configuration again. If that doesn't fix it I'll read through the power up procedures again. Probably one switch or c/b (or more) I missed.

Likely something missed in instrumentation or signal conditioning, those provide the power for those signals. Check the TM powerup procedure for anything missed.

 

[Wedge313]

Likely something missed in instrumentation or signal conditioning, those provide the power for those signals. Check the TM powerup procedure for anything missed.

This was the procedure they read up at about 101:08? I walked through that, trying each step to see if I'd get any indications, and closing the Flt Bus Main B c/b on panel 225 gives me indications on the panel 101 system test meter.

With my limited understanding of the system, the heaters themselves are powered by Main A and B, so the Flt Bus breaker shouldn't affect that. There is some stuff on the Flt Bus that might be affecting me, like the signal conditioning equipment? But the baseline configuration has the Flt Bus breakers open.

Here's a save at 136:14. At this point I've reviewed my baseline configuration, with the modification of the LM-to-CM power steps, and then ran the Entry Sequence steps at EI -6+30. I'm at a loss trying to figure out what I configured incorrectly.

Thanks

 

[rcflyinghokie]

This was the procedure they read up at about 101:08? I walked through that, trying each step to see if I'd get any indications, and closing the Flt Bus Main B c/b on panel 225 gives me indications on the panel 101 system test meter.

With my limited understanding of the system, the heaters themselves are powered by Main A and B, so the Flt Bus breaker shouldn't affect that. There is some stuff on the Flt Bus that might be affecting me, like the signal conditioning equipment? But the baseline configuration has the Flt Bus breakers open.

Here's a save at 136:14. At this point I've reviewed my baseline configuration, with the modification of the LM-to-CM power steps, and then ran the Entry Sequence steps at EI -6+30. I'm at a loss trying to figure out what I configured incorrectly.

Thanks

I am referring to this TM procedure which was used to read, among other things, the systems test meter. Also no save was attached to the last post

 

[Wedge313]

Yes that's the one, when I got to the Flt Bus MN B closed the meter sprang to life.