Ascent advice

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
Had a first run through with initial 1st stage ascent last night, went kind of ok, i'm not sure if there are any small things that need correcting in the flow on LM after that as i seemed to get hung up with the odd OP Err. I also had issues again with the rescue radar only just locking (tried manual slew then back to AGC). I used the CSM Att 0/250/0 as it went overhead and 0/320/0 after the climb. This seemed to be what was in the flight plan. By the end of the Ascent phase (before CSI), lock was hard, if not impossible, to achieve.

1) What CSM attitudes should I be using for ascent, CSI, TDI, etc?
2) Should I start the CSM checklist as shown here at this time? the yellow csm checklist items normally have the RPY this doesnt.

1613306968659.png
 

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
i also have probs now getting either the move to FDAI atts in the P52 or indeed after the V67E later in hte checklist, after PRO is hit I dont get F37 itts just a black dsky screen as if nothing is running. I made sure I unglitched the DAP starting but not sure if there's anything else that may not be exactly right

1613308546499.png
 

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
here's my homework sir :)
 

Attachments

  • Moon Ascent Just Before P52.zip
    61.4 KB · Views: 51

indy91

Addon Developer
Addon Developer
Joined
Oct 26, 2011
Messages
994
Reaction score
291
Points
78
1) What CSM attitudes should I be using for ascent, CSI, TDI, etc?

The attitudes you used are relative to the ORDEAL driven FDAI, so relative to local horizontal. After insertion the CSM is supposed to have 119° inertial pitch. That is probably a good attitude to use if you don't want to spend too much time in the CSM. So just use V49 to get to 0,119,0 some time before the ascent. I might add this to the checklist.

2) Should I start the CSM checklist as shown here at this time? the yellow csm checklist items normally have the RPY this doesnt.

Hmm no, the docking checklist is for the time when the CSM and LM are already together again, station keeping at a little distance. The checklist has basically nothing for the CSM during this time. It's a bit outdated, at the very least the rendezvous radar transponder in the CSM should be powered. That wasn't required yet when the Checklist MFD file for Apollo 11 had its last major update.

i also have probs now getting either the move to FDAI atts in the P52 or indeed after the V67E later in hte checklist, after PRO is hit I dont get F37 itts just a black dsky screen as if nothing is running. I made sure I unglitched the DAP starting but not sure if there's anything else that may not be exactly right

Uhhh, do you have the ANUN/NUM rotational switch completely to the dim position? The DSKY really shouldn't be completely black. Otherwise you have some major power failure, either inverter off (no AC power) or no power at all. You didn't pull the LGC/DSKY breaker, did you?
 

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
noted on the first 2 parts . i've also just completed the P52 with a 0006 accuracy . After the PRO it lookd like this. I've been relying on the checklist for switch settings and trying to work through the LM timeline book.

1613314901338.png
.
 

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
the 20E then generates an OP ERR as it's not going into anything, but, the F37, never appears.
 

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
yup thats what it is the checklist has a glitch there and is looking for F37 instead of starting P20 with V37
My next 2 issues are i'm sitting here and saying when marks=1 but i dont have anything on the dsky.
Also, i've completed down to here as quick as poss and i'm < 30m from CSI do I have enough time as the time below shows i should be starting CSI 18 minutes ago.
the radar is just and no more locked
1613315623463.png
 

indy91

Addon Developer
Addon Developer
Joined
Oct 26, 2011
Messages
994
Reaction score
291
Points
78
Yeah the checklist hasn't been refined yet in the later half of the mission. The main issue there is that the P52 checklist is generic, so it goes back to P00 at the end of it. But the rendezvous checklist is taken from the LM Rendezvous Procedures document, which assumes that you didn't do the "00E" at the end of P52 when V37 is flashing. So yeah, small flaw in the checklist, just do V37E 20E.

The part with the one mark is also taken from the LM Rendezvous Procedures. Not sure what they were thinking there. I mean, with a bit of experience you can see when the LGC is processing a mark. The COMP ACTY light will be on constant for a bunch of seconds and then when that is over the mark has been processed. You can also call V16 N45 and check the number in R1. It will take less than a minute for this to process in the LGC, so just wait a bit and then proceed with the checklist.

The times there are for a nominal mission, your maneuver times might be delayed by a few minutes. So you can try to keep following the timeline and it might work out, but it seems quite late already. You might have to go back to a scenario after insertion or so and try again.

the radar is just and no more locked

What does that mean? Has your rendezvous radar locked onto the CSM or not?
 

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
i was meaning the radar still struggles to maintain lock, it's weak
 

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
changing the exit from the P52 to 20 instead of 00 brought me straight into gimbal lock and trying to do the 20E manually also didnt work.

I assume the V16 N45 should also be in the checklist to display the mark value. When I look i have 1 mark but I don't see the F06 99 Monitor convergance

If all these for Ascent stage are being re-wored i will wait for them to be finished, or is my debugging helpful is so, i'll carry on.
 

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
also can P20 be killed off after that ? The next phase loads P32
 

Thespacer

Active member
Joined
Oct 26, 2019
Messages
96
Reaction score
42
Points
33
The post-insertion/pre-CSI activities are definitely quick-paced. In my case, practice made (relatively) perfect, as well as using the real rendezvous procedures I linked in your other thread (https://www.ibiblio.org/apollo/Documents/Mission_G_Rendezvous.pdf), which helps identify where the checklist MFD is in error. For example, the checklist MFD does not include the second occasion where you enter V48 to widen the att hold deadband. If it is still in narrow deadband (which was entered just before the P52) then you might find you run out of RCS by the time of rendezvous (or at least that’s what happened to me once).

Point is... if you’re solely relying on the checklist MFD, you may struggle.

Some other observations, going back to time-management: a lot of the procedure is waiting for the LGC to take marks. If you have started the CSI procedure late, then if you wait for 10 marks (per the checklist/actual procedure), you may find you blow the timeline. I’m not sure about the technicalities, but it may be possible to get just as good a solution with fewer marks (I normally get about 7-8 marks before having to move on), and that seems ok. Also, squeezing in the plane change manoeuvre can make the CDH phase very difficult, I think you can blow it off, however, if your Ydot is <2fps, which should be the case if all has gone well up to that point. I know the real Apollo 11 did not have to conduct a LM plane change.
 
Last edited:

Thespacer

Active member
Joined
Oct 26, 2019
Messages
96
Reaction score
42
Points
33
also can P20 be killed off after that ? The next phase loads P32
P20, once entered, stays “on.” Namely, if you’re in P20, and then do V37E 32E, the CSI program will load, while the P20 program will stay on in the background, one of very few programs to have this functionality, IIRC. P20 continues to take marks as long as V80 has been entered, throughout the whole CSI-CDH-TPI process, and as long as the RR maintains a lock. Every now and then, you‘ll be reminded P20 is running because you may find the LM has drifted off from the gimbal angles required to maintain RR lock, so you’ll see a random F 50 18 asking you to manoeuvre the spacecraft.
 

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
Thanks that's filled in the blanks for me. The issue was when the incorrect exit from the P52 then knocked onto the OP ERR, i think I hit reset which will have killed P20&
Not sure what's happened with my MCC timeline, I got past ascent and P52 as quickly as I could and i'm 20 mins from CSI. Not sure where i can compress more time from, most of the data input pre-CSI I did 0.1x to try and help.

Is there any video online showing the ascent after the intial takeoff stage?
 

indy91

Addon Developer
Addon Developer
Joined
Oct 26, 2011
Messages
994
Reaction score
291
Points
78
It's easy to run behind, but in general the time between insertion and CSI should be enough, with practice. I got 17 marks between the P52 and PROing at T-12min. So I must have finished the P52 at roughly 30 minutes before CSI. The nominal timeline has these relative event times:

Insertion+4min: Start P52
Insertion+17min: Finish P52
CSI-34 min: Start P20
CSI-32 min: Start P32
CSI-22 min: 10 marks, recycle P32
CSI-12min: Final pass through P32

In which of these steps do you think you are loosing the most time? Starting P52 just four minutes after insertion seems very ambitious, finishing by 17 minutes is tricky, but possible. If you are at least within 5-8 minutes of the nominal timeline it should all work out. Just from T-12min on you need to be exactly on time. At worst you are not getting all that many marks in. Even if you don't do the recycle at 10 marks and have to do the PRO at CSI-12min directly, still not too bad.

Do you mean a video of the procedures between insertion and CSI? I don't think there is. I could maybe record one, not like a tutorial, but as reference for "nominal" procedures.
 

sw34669

Active member
Joined
Dec 16, 2020
Messages
202
Reaction score
29
Points
28
Location
uk
Oh thats just boasting now and a challenge ..... 17 Marks (I thought we were on the euro now)
This is very helpful advice, my P52's leave a lot to be desired I think they need work
If you have any time to make even a bare bones vid (like your Apollo 10 landing or the Apollo 14 Abort button over-ride vids) if i can follow along it will help a lot. This way i can compare what i'm doing too slowly. I've read the docs, been through the checklists etc .
Thanks !
 

rcflyinghokie13

LM Junky
Addon Developer
Joined
Jun 4, 2016
Messages
144
Reaction score
33
Points
28
Oh thats just boasting now and a challenge ..... 17 Marks (I thought we were on the euro now)
This is very helpful advice, my P52's leave a lot to be desired I think they need work
If you have any time to make even a bare bones vid (like your Apollo 10 landing or the Apollo 14 Abort button over-ride vids) if i can follow along it will help a lot. This way i can compare what i'm doing too slowly. I've read the docs, been through the checklists etc .
Thanks !
That's probably not a bad idea. I think I will run through the G mission checklists again and try recording a rendezvous video.
 

Thespacer

Active member
Joined
Oct 26, 2019
Messages
96
Reaction score
42
Points
33
Another reference for many procedures is the post-mission technical debrief for each mission. You can pick up many little nuggets that have relevance to NASSP. For example, it turns out the Apollo 11 crew only commenced CSI about 27mins from nominal burn time. So, they too were running late (see https://www.hq.nasa.gov/alsj/a11/a11tecdbrf.html).

I’m unfortunately unable to help with the video, but this is one procedure I’ve practised many times, if you have further questions.
 
Top