Wrong attitude on p63

[proper ridge]

Did I miss a procedure when I was activating the LM, when I went to do my p63 burn i was upside down and I tried to go manual but I lost control of the spacecraft.

[fleet shadow]

did you enter the values for the PDI attitude you were given in the PAD?

[proper ridge]

I used the default on the checklist

[fleet shadow]

the P63 checklist doesnt have default values

[proper ridge]

+11000 is the only thing I edited using verb 21 or 22 on one of the nouns for p63

[fleet shadow]

should be V22 for pitch, so thats seems right

and+11000 is right also

did you have your Roll Pitch and Yaw set to MODE CONT and PGNS set to AUTO?

[pliant girder]

Just a little aside, when in GUID CONT PGNS and the PGNS switch is in AUTO or ATT HOLD, being in PULSE or MODE CONT makes no difference in the actual vehicle 🙂

but yes PDI (or any maneuver with AGS followup) is in MODE CONT so AGS actually can control should the need arise

[proper ridge]

according to checklist it had PNGS and AGS are both auto and I put all three of the directions in mode cont. so the computer would take over attitude of the space craft but when it got done maneuvering it was upside down. i canceled p63 and tried to go manual but my rcs directions kept getting crossed and I lost control; also I got a master alarm at P63 don't know what it was. I flew blind the whole mission pretty much when i crossed the moons SOI the DAP and P30 and P40 were useless to get into retrograde to fire the SPS and the Transposition and docking I had to do all of that manually too. Also I modified my landing site.

[fleet shadow]

shows that i need a followup on the LM G&N lol

[proper ridge]

I may try to review the LM activation to touchdown to see if i missed any thing, I got pretty close to getting the achievement, got way closer than I expected.

[boreal briar]

The P63 checklist has you set Roll and Yaw to Pulse in Reentry, which is weird and denies the LGC roll and yaw control in game. I just skip that step and forget it even exists 😄

[pliant girder]

why would it deny roll and yaw control

or is that how the behavior is in reentry

[boreal briar]

how the behavior is in Reentry

[pliant girder]

ah yeah pulse or mode control dont make a difference to the PGNS

IRL

AGS though, it matters

[proper ridge]

which is why I turned them from pulse to mode cont. but I was still in the wrong orientation

[pliant girder]

what N18 did P63 show when you entered it

[proper ridge]

is that the noun for attitude control

[boreal briar]

oh yeah that’s the other thing, P63 doesn’t calculate an attitude. PDI is always done at 0,110,0 and you enter that in N18 (in Reentry, not IRL)

even the checklist has V22E+11000E in it

[proper ridge]

that what I did verb 22 +11000 enter

the landing radar and rndzv radar cb were closed and active before p63

[boreal briar]

I have noticed minor attitude transients before the LR comes in. But nothing as major as what you described

did you have the ORDEAL on? That can screw up the guidance quite badly

[proper ridge]

I set it to lunar but I don't know if there was a switch to turn it on, I switched between ordeal and intrl, and it did nothing

[boreal briar]

was it in inrtl when you did PDI?

both FDAI switches?

[proper ridge]

it was in ordeal but I think I switched both tor intrl sometime in p63 to see if i could get the lm to reconfigure its orientation but it didnt work

[boreal briar]

switching in the middle of PDI will cause that type of upset

I did it once and ended up docking port toward the moon

[proper ridge]

Is it supposed to be in ordeal, is there an on switch?

[boreal briar]

it is supposed to be in inrtl on both switches

and pwr off to be safe

[proper ridge]

so its not supposed to be running, cb or switch

[boreal briar]

CB is fine, but switches need to be off

[proper ridge]

I did the DOI manually and I attempted the pdi manually by v37 n00 and roll pitch and yaw to direct, jets to throttle and engine start but as i got closer to the moon the rcs directions crossed and I lost control.

that was after p63 failed and the master alarm went off

[pliant girder]

this kind of thing is why its so hard to help people in reentry

[proper ridge]

roll turned into yaw and yaw became roll and I lost control of the lm and I had no throttle control on the engine either, I thought the jets to throttle its what switched it from rcs to throttle up and down. even if I would have not lost control, the engine control would have stopped me from landing. im going to study up on lm activation through landing and see if i missed anything. and then attempt another launch and see if i can make it to the moon in one go, almost had it now its just getting to the surface. I can get to the moon and into my stable orbit for PDI.

[pliant girder]

Yeah coming from NASSP and the actual systems its hard to say if what you did was correct or incorrect for Reentry

[proper ridge]

I figured out why the csm had no attitude. I didn’t do the imu alignment.

[proper ridge]

So I did everything right in the activation procedure, the only thing i missed is the IMU set up after undocking so how do you realign the LM's IMU to get attitude for the moon? also V49 E, V06 N22, V23 +18000 in R3 should put the spacecraft into a retrograde attitude, correct? R1 +00000, R2 +00000, R3 +18000.

[fleet shadow]

in the LM yaw will make you spin around the vertical axis, so you would want pitch, or R2, to be +18000

[proper ridge]

when i punched it into r3 i was perpendicular to the retrograde attitude but i was in the academy lesson for the flight modes

[fleet shadow]

also LM P52s for platform alignments are currently not in Reentry

also IRL LM V49s dont directly show what attitude the FDAI shows since the LM IMU is not like the CSMs in how its aligned with the spacecraft axis

[proper ridge]

so how does the LM get its attitude currently as implemented

[fleet shadow]

same as the CSM i believe, N20 (IMU) angles are the same as the FDAI

IE V49 works like it does in the CSM

and the platform is aligned to the landing site when you set it on the map

[proper ridge]

I changed my landing site prior to PDI request did that have anything to do with it?

[fleet shadow]

thats what you should do

[proper ridge]

Do i need to do the IMU alignment after LM extraction or when im at perilune for LOI or after I have been captured in lunar orbit because I did all of that manually except the TLI burn it was done with p15

[fleet shadow]

the LM is not used really until landing day when its all activated and checked out

there are checkouts during TLC but those arent done in reentry

[proper ridge]

yep thats why i kept it powered off until just before attempting to land but i had to do my LOI burn manually VFR because the DAP was pointing me in the wrong direction so i used the sps direct thrust lever to do my burns and watched the orbit map and got down to about and 80 mile orbit then I activated the lm and did my DOI manually too because I had no attitude control to do p30 and p40 burns. then when i went to go for PDI i was in the wrong attitude upside down

[fleet shadow]

have you been doing REFSMMAT updates for the burns? in reentry you can request a REFSMMAT which will make the burn attitude 0 for roll pitch and yaw. doing so requires you to do a P52 option 1 i believe, might be 2. whatever the Preferred option is.

in the CSM

[proper ridge]

No I haven't, I wanted to see how far I could get just following the checklist and doing a few of the academy lessons but i got pretty far farther than I Expected, I can deal with the CSM not having navigation but the LM's a different story.

I can realign when i get ready to leave lunar orbit to do my TEI

[fleet shadow]

yeah its good practice for reentry at least to request a burn REFSMMAT and do the P52 to ensure things work right as it can still have some bugs

[proper ridge]

im in the LM, did my DAP setup V 49, V06 N22 R1 +00000, +18000, +00000 puts me in the same perpendicular orientation, what do i key in to get retro grade

did the same weither i put it in R2 or R3

I tried +09000, +11000, nothing put me in the proper orientation, pre set mission lm activation

[fleet shadow]

again yaw, or R3, is like Roll in the CSM. it rotates about the vertical axis, thus having no real effect on your pointing vector. also because the IMU is an inertial reference, Retrograde isnt one specific attitude because you are orbiting the planet

[proper ridge]

then how do i get aligned to do my burn for p30 and p40 without going to manual control?

[craggy meteor]

How do you "undo" the REFSMMAT when completed? (run P52 again with a R2 = +00000? I suppose I can try it later)

I also had the same issue as OP here last night trying to get my One Small Step badge on the 55th anniversary of the lunar landing. I've run the LM Descent probably 10 times in the past week and it went fine. Then last night I was oriented almost prograde and dummy me forgot to disable Engine Arm and it fired while I was trying to cancel P63 (which isn't easy to cancel, it ignores V34E, 37/00, etc). I managed to get it stopped before it crashed me into the Moon and I recovered from that into a new orbit (roughly 24x8.5 after a couple of burns) (I don't know if you can realistically fire DES multiple times like I did but that aside...) requested a new PDI.. left my orientation even worse on that pass... tried one last time (with batteries draining away) and it was finally oriented correctly, ran P63 fine, P64, all the way down to 2k and then it immediately pitched me facing upwards and then just went bonkers spinning around like crazy. I wonder if it was because my IMU or FDAI or whatever it is that is aligned to the landing location was setup incorrectly.

At no point had I done a P52 in that particular mission because I had not needed to in my practice runs and I keep having issues with it afterwards.

[fleet shadow]

you dont "undo" a REFSMMAT. its the spacecrafts idea of where you are pointing, with different references. setting R2 to +00000 would be trying to run a P52 option 0, which doesnt exist, and would probably cause an OPR ERR light on the DSKY. also the practice of getting a REFSMMAT for each burn isnt how it would be done IRL. they would be on a PTC REFSMMAT, which you can get in Reentry, and would only go to a burn REFSMMAT if the burn attitude in the current REFSMMAT would put them into gimbal lock. P52s in the LM are not supported yet, and you align your IMU to the landing site using the map screen when you set your target. another thing is make sure the ORDEAL is turned off when doing burns and especially during PDI

i should really fly a mission and see if i get all these issues too

[craggy meteor]

First of all I'm ONLY talking about the game/sim here as are most people -- additional info is wonderful but not directly helpful to game questions.

Here is what I mean... over in the CM I ran P49 set to +0 +0 +0, my ORDEAL is set to Orbital / Lunar and I'm pointing off into LA LA land.

I tried ORDEAL set to INRTL and LUNAR and get the second result -- also pointing off into LA LA land but a different direction.

Earlier it was pointing me prograde, now it is completely hosed. So, in game, is there anyway to get it realigned to my orbit?

Likewise over in the LM it seems like ORB RATE/LUNAR is working ok this time (it doesn't always), but INTRL is still "stuck" at my landing site (possibly)... The question is, in game, can I reset it back to what it was before I set a landing site?

[fleet shadow]

i give real world stuff mainly for context and to explain why things are done the way they are, sorry if its too much. the only way to go back to an old REFSMMAT is to have it re-uplinked, which isnt simulated in the LM, so it is always "stuck" at the set landing site on the map. a Landing Site REFSMMAT is the same as a Liftoff REFSMMAT, being approximately 0,0,0 at the landing site so there is no need to change them regardless. i would try having the ORDEAL set to OFF just to be sure it doesnt mess with anything, as others have reported the ORDEAL actually changes the IMU alignment instead of just driving the FDAI as it should

[craggy meteor]

I found one solution (which could potentially cause issues on reentry) in the CM, [1] IMU Cage on, manually adjust attitude, IMU Cage off.

[boreal briar]

That is a way to realign the IMU without P5X, yes

might break things though

the LM abort guidance computer would be aligned in a similar way if the primary computer wasn’t available to pass on an alignment, actually

a double star sighting would be made, MSFN would pass up an attitude, you would maneuver to it and then tell the AGS to align to 0,0,0

[proper ridge]

@fleet shadow I just finished gemini and getting back to apollo, I am learning how to do the ressmmat, how do I start cmc and iss? they are requried before doing p51 and p52. what panel are they located at?

[fleet shadow]

the CMC is the computer, so make sure that is on, and ISS is the IMU pretty much, they are started pre launch so they should be on already

[proper ridge]

Im going to try it out later when I get a chance just have figured out how to move the telescope and sextant.

[craggy meteor]

control -arrow keys usually, check input mapping under equipment for Right/Left, Up/Down (or slew if you have a controller mapped)

[proper ridge]

Do you have to realign after csm lv sep or when you get in the moons soi or lunar orbit. Also what is the desired orbital altitude for the csm for LOI.

[fleet shadow]

IRL they did LOI-1 to a 60x170 nmi orbit, and early missions did a LOI-2 to a 60x60 and a LM DOI, and later missions used the CSM for a DOI for a 60x9.8 nmi orbit after LOI

and ideally in reentry you do the LOI then DOI, and use a REFSMMAT for the LOI burn

after CSM LV sep they would get a PTC REFSMMAT on later missions, this you can do in reentry

[craggy meteor]

Yes, need to rotisserie the CSM while coasting, great solution to that problem. I

But the problem here really is that sometimes ReEntry will just get into some very confused state where it doesn't know which way is up, even in ORB RATE. The question is, once in that state (that is hard to reproduce) is there some way out of it or best to just abandon that run and start over. Sometimes it could be something I have done but sometimes it definitely is not, especially as I have become more familiar with all the steps I am taking. There is a bug in there somewhere.

[fleet shadow]

not to be cheesy, but up is relative in space haha. i need to fly a mission in reentry and see how it goes on my end

ive never had that problem before, so im not sure tbh

[proper ridge]

@fleet shadow is the imu in the LM slaved to the one in the CM since p52 isn’t supported in the LM yet?

[fleet shadow]

its slaved to the LS

[proper ridge]

Ls?

[craggy meteor]

I think Landing Spot maybe? It's oriented for the designated landing location anyway. If you move that marker using << < > >> buttons on the map you can see your FDAI rotate also.

[pliant girder]

Landing Site

[fleet shadow]

ah my bad should have clarified haha

[proper ridge]

so when you edit your landing site theoretically it should update the imu correct?

[proper ridge]

well status report, p52 worked somewhat p49 r3 +18000 put me in a prograde attitude so I say that is somewhat of a success. question is campaign 3 bugged I got the target perilune and executed TLI burn with p52 and then it got stuck on using the TLI planner even after I made the burn with the correct target altitude.

[fleet shadow]

yep

only in the LM

the CSM doesnt have an LS REFSMMAT

[proper ridge]

I have solved my problem I think, I'm going for another attempt. I just used the default landing site and it worked its in the correct orientation

[proper ridge]

question, how do I get manual throttle control on the lunar module using rcs keys for fwd and aft

[boreal briar]

throttle to manual on Panel 1, throttle/jets to throttle by the translation controller, and up and down translation to throttle

[craggy meteor]

Is that how it really worked, with no proportional throttle control? Makes it hard to land manually (had to do that a couple of times). Maybe in Apollo they would have just aborted using the Ascent module. I was thinking to try to dig out the old flight controls.

[fleet shadow]

Wdym by proportional?

[craggy meteor]

Like a throttle. As opposed to push a button to increase by some amount and another to decrease, like how the ROD works or using the RCS controls in place of a normal throttle.

[proper ridge]

I got the achievement but I glitched straight though the moon ended up landing on the other side, now on to the ascent, rendezvou and docking.

[craggy meteor]

One Small Step is no small achievement (even if it glitches), congrats!

[proper ridge]

@craggy meteor Everything was fine until p64, after that I went to manual and I started going up and then I shut the engine off and time warped down so fast I fell through the moon and landed on the other side in a mountain range, I thought I was going to stick the landing this time but hey a win is a win. I decided to do every thing after TLI manually, the T&D and LOI using SPS direct thrust and just looking at the moon for my attitude, then just activated the LM according to the procedures, I figured out what I did wrong on the lunar module was with the map setting the IMU, so after I figured that out I was in the correct attitude to land and P63 V99 PRO and things got weird after P64. I don't know how I started going back up when I had the engine as low as it would go?

[fleet shadow]

you typically dont go manual until P65/66

in P64 you are still way up there

i misspoke, havent done a landing in a while. going to ATT HOLD triggers P66, its done around 200ft

[pliant girder]

500 on this timeline

[fleet shadow]

ahh that makes sense

thanks for that

[proper ridge]

@fleet shadow the attitude was still off a little and I was setting down in a craterous and mountain filled area so I decided to go to manual a little early so I could find a safe landing spot but some how I keep going up with the engine as low as I could get it and that's when I shut it off and was going to coast down but the timescale got away from me and I ended up glitching straight though the moon onto the other side, the other side was filled with mountains and i landed in a valley, although not upright though but i managed to exit the hatch for the achievement. if i had practiced the landing a little more I probbaly could have made it happen

[fleet shadow]

you should be able to change the landing site in P64 if reentry does things correctly. you use the LPD and its associated angle that you can either read off the DSKY or have the LMP read it to you in the Crew Members menu

[proper ridge]

the problem was I didn't know how to change the TFI which the landing site has to be 350 mi down range of the TFI. from what the academy lesson said

[pliant girder]

reentry does things correctly.
haha bane of my troubleshooting here

[fleet shadow]

yeah im not sure how the targeting really works in reentry, if it does that for you or you just have to guess

the tip i can give is if you do DOI yourself then make sure your PE is before the landing site

[proper ridge]

I had done the PDI request and it ended up putting me on the side of the moon with all of the craters, instead of the nice flat areas to land

if i had practiced the landing more I probably could have done a better job at it. but in the end it worked out, for a moment I thought I had lost the mission.

[fleet shadow]

if you didnt set the landing site then it defaults to somewhere on the farside

[proper ridge]

that was my fix to the wrong attitude problem I had i was going to use the default landing site which is suppose to be were apollo 11 landed but I guess something about my orbit changed that maybe?

[fleet shadow]

the default site isnt where 11 landed in my experience, its always been on the farside for me

[proper ridge]

in the missions tab under lunar module called descent that is the default landing site for that mission probably due to orbit characteristics, its set near Armstrong crater.

I did the mission from activation and found out that if i left the landing site alone it would put me on correct attitude for p63, so i just repeadeated it in my run for One Small Step.

I just want to finish out the apollo stuff before space shuttle and skylab get here. So next im doing the ascent, rendezvou and docking and im going to try to finish campaign 3 and 4.

But thanks for all of your help it was useful.

[craggy meteor]

I think it's about 20 deg downrange from your periapsis isn't it?

[proper ridge]

350 mi is what the academy lesson said and after I did that I was in the correct attitude for p63, I might experiment with this later using different landing sites if this will correct the imu, or if its changing the TFI to your landing site, or changing your PE.

[craggy meteor]

I just did a non-standard landing site. Pretty sure you need to set the landing site to ~350 nmi from your Pe (that's about 20 deg near the equator).

GRRRRRRRRRRRRR I was just typing in my save file name ("full-8") and guess what it does... fast forward 500x time on the '8' entry.... WAY past my TDI time. Sometimes the bugs are starting to get to me... /sigh/

[proper ridge]

Need Help with the lunar orbital rendezvous, can get within visual distance of each other with the rendezvous lights but space crafts orbits are not aligned after TFI, and are drifting apart. Is another burn required? am I missing something? thrusting to the target does nothing spacecrafts are too far apart,

[craggy meteor]

The simplified procedures in ReEntry are:
First make sure the CSM is circular up near 60nmi x 60nmi, the more circular the better, at least within .1 or .2 of the same value
Then first circularize the LM at your Pe
Only then request & execute the TPI burn, that will raise your apoapsis up to the CSM orbit
Then immediately request the TPF burn after you complete the TPI, it should be 1/2 orbit away at your new apoapsis
That TPF will get your orbits pretty closely aligned for the final rendezvous using the radar.
Use the map view to fine tune that if needed. If you are far behind the CSM lower both your AP and PE to just a bit below the CSM so you catch up
If you are too far ahead, then raise your orbit a little bit until the CSM catches up
When within a "reasonable" distance you can just burn towards the target and then be ready to break as you get closer (you'll also need to burn radially to compensate as you close)

[proper ridge]

@craggy meteor So In the academy lesson and once P12 is over it tells me to slew the radar, then setup p20, then request CSI burn and setup and execute with p30 and p41, then TPI burn the same way and then it says I should be within distance to dock, Have not done a TPF burn, after TPI I am within visual distance of each other but no matter how much I thurst to one another its not enough, even tried the sps.

[craggy meteor]

TPI is the Terminal Phase Initiation burn and then TPF is the Terminal Phase Final burn, that is the one that will put you in nearly the same orbit as the CSM. If the lesson doesn't have that maybe it's broken? I'm not sure why that would be. But give it a shot. Here is mine just a little bit ago. This is immediately following the TPF burn and I'm within about 500 feet and in nearly the same orbit. Honestly you can skip P20 also and just use V49 to set +0, +0, +0 and do the burns that way, then P20 after TPF if you still need it.

[proper ridge]

that's probably what I'm missing, thanks @craggy meteor I will give it another attempt.

[proven mesa]

Gave +1 flight-hours to @craggy meteor (current: #48 - 6)

[fleet shadow]

Ascent and rendezvous is hit or miss in reentry unfortunately, I’ve only done it a few times myself

[proper ridge]

Thanks @craggy meteor Mission Accomplished, the docking took several attempts but I got It.

[proven mesa]

Gave +1 flight-hours to @craggy meteor (current: #44 - 7)

[proper ridge]

I am now trying to finish campaign 3

[craggy meteor]

Congrats! It's painful... now that you have done it that way I have another short cut that saves me some frustration.

For that final docking, try setting both CSM and LM to ORB RATE/LUNAR and orient the CSM using V49 to attitude (+14000 +18000 +0) and the LM to (+0 +27000 +0) and then dock using only translation, they will be aligned without fighting pitch, yaw, and roll. I consider this a fair trade off for having only a single pilot for both spacecraft. You'll want to switch to FREE mode right before you dock (ideally in both but again being one person makes it hard, you switch to free too soon and things will go haywire). I think there is also a bug that when you switch the CSM from AUTO to FREE it will fire the RCS and set you spinning sometimes (maybe Hold is confusing it, even when you are in a stable orientation). If the LM is in front of the CSM you can just coast back or invert the orientations.

I haven't tried this in combination with P20, if that messes with the IMU/FDAI orientations you might need to not use P20... I don't think ReEntry handles the IMU very well. In the real mission (from my understanding) they would transfer the state vector from the LM to the CSM so they could align, maybe someone with more knowledge on the details can comment but I'm pretty sure they used the DAP indirectly (no using V49 but other programs/routines).

Apollo 11 Flight Plan: https://www.nasa.gov/wp-content/uploads/static/apollo50th/pdf/a11final-fltpln.pdf

Starting on page 196 with docking on page 200 (3-94), suggests they used programs & routines not in ReEntry.

[pliant girder]

In the real mission (from my understanding) they would transfer the state vector from the LM to the CSM so they could align, maybe someone with more knowledge on the details can comment but I'm pretty sure they used the DAP indirectly (no using V49 but other programs/routines).

are you referring to the final attitude for docking?

no state vectors were transferred (nor could they be unless done manually)

V89 was used in the CSM for the final tracking attitude (pointing the COAS at the LM based on its LM state vector) but later missions (Apollo 12+) used the attitudes in the flight plan as an initial reference and they were pretty close

[craggy meteor]

Reference:

https://www.nasa.gov/history/alsj/a11/a11.landing.html

102:24:04 Duke: Roger. We see your Verb 47.
...
102:25:43 Aldrin: Roger. (Long Pause)

[Armstrong - "It was a fairly simple procedure to send a state vector from one computer (the PGNS in this case) to the other (the AGS)."]

[Aldrin - "The AGS initialization was done by a Verb, an instruction with maybe a two- or three-digit code (Verb 47, as noted above)."]

[proper ridge]

Campaign 3 is complete, Now I just need SCE to AUX and Campaign 4

[pliant girder]

So its not transferring between vehicles, there are two "slots" in each computer to store a state vector. Typically when the CSM and LM are together, they keep an identical state vector in each as a backup, so V47 there takes the state vector in the "LM Slot" and copies it to the "CSM slot"

when the vehicles are apart, it can integrate the two state vectors separately so the LM can "remember" where the CSM and itself is in PGNS and AGS, and same for the CSM knowing where it is and the LM is at the same time

but nothing goes vehicle to vehicle