Apollo 7 P22 (And Other Questions)

[Wedge313]

Good Morning. I'm slogging my way through the Apollo 7 flight, I'm 122 hours into it and (following the PAMFD checklist) getting ready to do some P22s. But I haven't seen any uplinks (LAT/LONG) on which landmarks I'm going to want to mark. What have I missed here?

Also not sure if I have the correct flight plan for the flight. I've been working off a May 1, 1968 prelim copy, but the flight plan and the PAMFD don't seem to be in sync. I decided to press on using the PAMFD checklist. I think for this particular mission it gives me the basic essence of what they were doing?

And going back to the SPS-3 burn at around 75+48, the first time through I didn't get ignition. I realized my SPS fuel temps were zero, went back and re-did it after turning the SPS line heaters on for a while, and got auto ignition. I didn't see any other issue except for the SPS fuel temp, and didn't see any mention of it on the PAMFD checklist before the burn. I guess they figure that this is just basic systems knowledge and I should know this (which is true). The other question was why hit the Thrust On button? I got auto ignition, so I'm not clear on what they were testing here.

One small PAMFD checklist question: when going through the P40 checklist with the THC clockwise it asks us to verify no MTVC, then put the THC to neutral. Souldn't those steps be switched, THC to neutral then verify no MTVC?

Anyway, any help I can get on the upcoming P22 landmarks would be appreciated. Thanks for the help.

 

[rcflyinghokie]

Apollo 7 is mostly @indy91 's baby including the checklists. So I will defer to him on the P22 question. But from what I can see you are supposed to get landmark tracking updates there from MCC.

Here is Apollo 7's final flight plan: http://www.ibiblio.org/apollo/Documents/apollo7_final_flight_plan.pdf

For the SPS stuff, turning on the line heaters is part of the SPS checks, I have incorporated it into other P40 checklists but it looks like its missing from 7's checklists. I also don't remember any code that prevents the SPS from firing with cold temps currently, though I could be mistaken.

For the thrust on switch, SPS-3 is using SCS, so the CMC isn't lighting the SPS here so you need to use the thrust on switch.

The P40 checklist is correct, the THC should be in CW to "verify no MTVC" because gimbal motors P&Y 2 are not on. The MTVC is performed by the secondary P&Y motors, so you are conforming you dont have MTVC when using the primary motors.

 

[indy91]

You should have gotten a landmark tracking PAD with the coordinates to put into P22 at 121:06h GET. You had to write it down or something, because half an hour later it gets overwritten with P27 PAD for a manual state vector update. And there are more of these landmark tracking PADs later in the mission, but no associated uplinks.

I find it quite useful to study the landmark maps before the P22: http://www.ibiblio.org/apollo/Documents/A8-Landmark maps+photos-1004.pdf

But it's a bit hit or miss how visible the actual landmark is in Orbiter. Sometimes it's great, sometimes there are clouds and you see nothing.

 

[Wedge313]

The P40 checklist is correct, the THC should be in CW to "verify no MTVC" because gimbal motors P&Y 2 are not on. The MTVC is performed by the secondary P&Y motors, so you are conforming you dont have MTVC when using the primary motors.

Sorry, I didn't explain that clearly. My question concerned the second part of the check, after gimbal motors P2 and Y2 are on. The PAMFD checklist steps ask us to perform the MTVC check with the THC in the CW position (I get MTVC), then says "verify no MTVC" (I can't with the THC in CW), then has THC to neutral (now I can verify no MTVC). Other G&C checklists show this part of the check as (with the THC in CW) verify MTVC. Then THC to neutral, then verify no MTVC. Not a big deal, it just seems the PAMFD steps are out of order.

You should have gotten a landmark tracking PAD with the coordinates to put into P22 at 121:06h GET

I'm not getting this PAD. I went back again to 120+00, and worked forward. I have the SPS-4 PAD that I received around 117+30, then nothing until 121+36 when I get the P27 PAD. Is there some way I can generate this PAD? (It won't break my heart if I can't, P22s are not my favorite things to do.)

I also don't remember any code that prevents the SPS from firing with cold temps currently, though I could be mistaken.

For the thrust on switch, SPS-3 is using SCS, so the CMC isn't lighting the SPS here so you need to use the thrust on switch.

I'll have to go back and play with this. My recollection is that my first time through I got no ignition, and after troubleshooting the only abnormal thing I saw was the SPS fuel temp, and correcting that seemed to be the fix. Also I'm pretty sure the ignition occurred automatically without me hitting the THRUST ON, so now I want to go back and check my switch configuration. Of course, I didn't create a convenient save point before the burn, so I'll have to plow through some other things until I get to the fun stuff.

Thank you for the help.

 

[indy91]

Sorry, I didn't explain that clearly. My question concerned the second part of the check, after gimbal motors P2 and Y2 are on. The PAMFD checklist steps ask us to perform the MTVC check with the THC in the CW position (I get MTVC), then says "verify no MTVC" (I can't with the THC in CW), then has THC to neutral (now I can verify no MTVC). Other G&C checklists show this part of the check as (with the THC in CW) verify MTVC. Then THC to neutral, then verify no MTVC. Not a big deal, it just seems the PAMFD steps are out of order.



I'm not getting this PAD. I went back again to 120+00, and worked forward. I have the SPS-4 PAD that I received around 117+30, then nothing until 121+36 when I get the P27 PAD. Is there some way I can generate this PAD? (It won't break my heart if I can't, P22s are not my favorite things to do.)

I think you are on an outdated version of NASSP. In September I flew Apollo 7 and did a bunch of updates for the MCC and checklist. As part of that I added the landmark tracking PADs and I also fixed the MTVC checks in the checklists. That is all in the most recent NASSP 8 Beta releases: https://github.com/orbiternassp/NASSP/releases

You should be able to update mid-mission, even with the MCC updates. If you don't want to do that you can use the RTCC MFD, under Pre-Advisory Data, Landmark Tracking PAD.

I'll have to go back and play with this. My recollection is that my first time through I got no ignition, and after troubleshooting the only abnormal thing I saw was the SPS fuel temp, and correcting that seemed to be the fix. Also I'm pretty sure the ignition occurred automatically without me hitting the THRUST ON, so now I want to go back and check my switch configuration. Of course, I didn't create a convenient save point before the burn, so I'll have to plow through some other things until I get to the fun stuff.

Thank you for the help.

If the CMC is in control it will start the engine after you press PRO on the DSKY. If the SCS is in control it needs an ullage signal present, even if just for a second, and then the thrust on switch. The checklist might be slightly confusing, you are still pressing PRO like normal so that P40 switches properly to the next display, but if the SCS is in control only the SCS can start the engine, there is no auto ignition.

 

[Wedge313]

I think you are on an outdated version of NASSP

That's probably it. My last update was v.1922 back in August.

I'll still go back and re-do SPS-3. I'm curious what actually happened, as opposed to what I remember.

Thanks

 

[Wedge313]

Re-did the SPS-3. Not entirely sure what was going on the first time, but this time it worked the way it's supposed to. Definitely no auto ignition, I had to mash the THRUST ON button.

One weird thing I did notice, for some reason when I re-ran the scenario from a save point around 74+11 the PAMFD checklist pulled up a "normal" P40 Thrusting checklist instead of the "SPS Thrusting + Slosh Test" checklist. That leaves the SC CONT in CMC, and maybe that's what happened when I was trouble-shooting the first time, I got derailed onto the wrong checklist? Either that or insuffcient caffination. Whatever. Operator error, All is well now, I'll upgrade my NASSP version and press on.

Thanks