Apollo 11: No Texture and PDI Questions

[Wedge313]

Hello,

When I installed Orbiter Beta I did not download the high-rez textures, I linked to the textures from Orbiter2016. I tried to install the microtextures, but I'm doing something wrong. As I approach landing, there are no terrain features, it's like landing on a glacier in fog. I tried unzipping the microtextures into the textures file on both Orbiter and Orbiter Beta, but no luck. Can someone help me do this correctly?

PDI questions: Before PDI, after the AGS update the checklist has a step where you input 240+into the AGS, and then in yellow has (230 RLS). I'm unsure what I'm supposed to do here.

Later in the powered descent, at 5 minutes the DSKY shows V16N58, and the checklist instructs "when dH within limits". What are the limits?

Finally, what do I do to get the LGC to switch from P64 to P66? Is there a switch I have to flip? I thought when I started to manually maneuver the LM it would switch to P66 by itself, but I remain in P64. (On a side note, isn't there a P65 somewhere? An "if I don't touch anything it will land automatically" program? For some reason I think I've seen that somewhere.

Obviously I have a lot to learn about the powered descent.

(EDIT: The copy of the Apollo GN&C manual that I have shows a section 8 in the Table of Contents that would seem to address these questions, but the whole section is missing from the copy I have. Where can I learn about these descent programs?)

Thanks.

 

[indy91]

Hello,

When I installed Orbiter Beta I did not download the high-rez textures, I linked to the textures from Orbiter2016. I tried to install the microtextures, but I'm doing something wrong. As I approach landing, there are no terrain features, it's like landing on a glacier in fog. I tried unzipping the microtextures into the textures file on both Orbiter and Orbiter Beta, but no luck. Can someone help me do this correctly?

I'm not quite sure, maybe you have enable them under Video, Advanced in the Orbiter launchpad?

PDI questions: Before PDI, after the AGS update the checklist has a step where you input 240+into the AGS, and then in yellow has (230 RLS). I'm unsure what I'm supposed to do here.

You want to load the same number in address 240 as you have previously loaded into 231. Both are the landing site radius. 240, 262 and 254 are part of a manual state vector update for the AGS that you are preparing before PDI and that you actually do later on the surface. You are basically going to load a state vector at the nominal landing site as that can be more accurate than the state vector currently in the AGS that went through the whole PDI with accelerometer biases, possible misalignment of the platform etc.

Later in the powered descent, at 5 minutes the DSKY shows V16N58, and the checklist instructs "when dH within limits". What are the limits?

I think the Timeline Book has some values for this on page 9, it's the DH values in brackets. Seems like an error of 17500 ft is acceptable down to 30000 ft, so that's highly unlikely that you are going to get values this large.

Finally, what do I do to get the LGC to switch from P64 to P66? Is there a switch I have to flip? I thought when I started to manually maneuver the LM it would switch to P66 by itself, but I remain in P64. (On a side note, isn't there a P65 somewhere? An "if I don't touch anything it will land automatically" program? For some reason I think I've seen that somewhere.

Apollo 11 and 12 had a P65 for automatic landing. It simply starts when P64 is done. You don't have to touch anything to get that. To get into P66 you need to be in PGNS Att Hold mode and then when use the rate-of-descent switch for the first time it will switch to P66. That switch is used with the keyboard:

Minus: Increase Descent Rate
Equals: Decrease Descent Rate

(EDIT: The copy of the Apollo GN&C manual that I have shows a section 8 in the Table of Contents that would seem to address these questions, but the whole section is missing from the copy I have. Where can I learn about these descent programs?)

The "User's Guide to Apollo GN&CS Major Modes and Routines"? Seems like revision 1 of the document is missing that section. Revision 4 is also available of that document, but it refers to later AGC software versions so it will confuse you more than help you. The AOH Volume 2 might be better, for Apollo 11 it's only available here: https://de.scribd.com/document/66115251/Apollo-Operations-Handbook-LM-5-and-Subsequent-Vol-II

The G&N Dictionary can also help a little bit: https://www.ibiblio.org/apollo/Documents/ApolloXI_FlightCrewG&NDictionary_5-29-1969.pdf

 

[Wedge313]

OK, copy me down, stop turning blue. Turns out it's easier to land when you press the right buttons and can actually SEE the surface.

As is usually the case, the problems I had were self-induced. I was loading the microtextures into the textures file, instead of the Orbiter Beta directory. Seemed to make sense to me, but no. All is working well now.

And instead of the "+" and "-" descent rate keys I was mashing the "0" and "." throttle keys.

Still a lot I want to go back and redo, try to get it to go smoothly. Read up on what's actually happening when I flip a switch or make a computer input. And then on with the flight.

Thanks for the help.