Talk:Apollo 12

Changes from Apollo 11?

I was hoping for a section saying what, if anything, was changed in the hardware from Apollo 11. Does someone know who could add a section? I'm guessing the 1202/1201 alarms and communication issues from 11 were addressed. Apepper (talk) 19:50, 21 July 2019 (UTC)

There was no significant hardware change. The computer alarm problem was diagnosed as caused by an antenna switch left in the improper position, so it was fixed by a procedural change; no hardware change was required. To what "communication issues" are you referring? JustinTime55 (talk) 13:33, 22 July 2019 (UTC)

Note that the rendezvous radar switch (not "an antenna switch") was _not_ "left in the improper position." The rendezvous radar switch was correctly set to "SLEW," as the landing procedure dictated. The crew correctly followed procedure and did exactly what they were supposed to—setting the switch to "SLEW" during descent meant the rendezvous radar would be ready for immediate use in case the landing had to be aborted and the LM had to acquire and re-join the CM. The issue, explained in penetrating detail by AGC programmer and primary source Don Eyles, was that there was a documentation oversight with the landing radar, and if its hardware was energized at precisely the right (or wrong) moment, it would be out of phase with a reference electrical signal and would send what appeared to be nonsense data to the AGC (specifically reporting that the radar's shaft and trunnion angles were invalid values—many values, very quickly. Servicing this nonsense data ate computer time and chewed up temporary storage areas, and eventually the AGC was unable to finish its job list in the time allotted and threw "I am out of temp storage areas" error (the "1201" and "1202" program alarms).

"The switch was set wrong" is a misconception that needs to die. The crew followed procedures to the letter. The procedures themselves contained the oversight. ~2026-34655-8 (talk) 16:45, 16 January 2026 (UTC)

Picture showing Alan Bean descending the ladder.

The picture is shown the wrong way. It should be reversed 24.202.244.63 (talk) 20:30, 28 February 2023 (UTC)

Typo?

In the section "Outward journey", second paragraph, I think "non-" should be added in the following sentence, as indicated with < >:

Apollo 12 was the first crewed spacecraft to take a hybrid <non->free-return trajectory

But maybe I’m missing something, so I didn’t go ahead and make the change myself. Any thoughts? Geke (talk) 12:55, 20 January 2024 (UTC)

If it's a typo, the original source makes the same mistake. p. 333-334. Was it free return until the midcourse burn and non-free return after? --Dual Freq (talk) 13:10, 20 January 2024 (UTC)

If it is a hybrid between free-return and non-free-return then surely hybrid free-return and hybrid non-free-return mean the same thing.

My understanding is that 12 did not have a 100% free-return trajectory (do absolutely nothing and you come home automatically). It's just that the required burn was small enough to be executed by either the SPS engine or the LM engine (as a backup), so that it was a close to free-return trajectory.  Stepho  talk  20:05, 20 January 2024 (UTC)

They did go off free return with their midcourse correction (see here, particularly the PAO commentary following 29:06:29). As I understand it, all of the Apollo missions after 11 did a hybrid free return trajectory that could be changed to a free return by either the SPS or the DPS, Apollo 13 famously so. Wehwalt (talk) 22:22, 20 January 2024 (UTC)

TV Troubles

I think it would be appropriate to mention the discussion of how this (pointing the camera into the Sun) came to happen, as described in https://www.nasa.gov/history/alsj/a12/a12.tvtrbls.html. I am not sure how to summarise what in that page, avoiding putting in too much of one's own interpretation of what is said. (I think it is mainly put down to not being covered in training.)

I have found that when trying to go to that page, sometimes I seemed to be re-directed to https://www.nasa.gov/history/alsj/ . (The URL in the reference "TV Troubles" in the article also goes here.) If that happens, click "Enter the Journal", then "APOLLO 12", then "TV Troubles". FrankSier (talk) 16:34, 12 October 2024 (UTC)

Not so much training but not having worked with an actual camera in training is how I read it. Why do we need to add more to what's already there? Wehwalt (talk) 17:07, 12 October 2024 (UTC)

I think that making such a big mistake, which meant that the planned first colour TV from the Moon did not happen, warrants an explanation in the article. The missions were meticulously planned, so how could this have happened? Without knowing the reasons people can only speculate: did they trip over? had the astronauts thought it would not matter pointing it at the Sun? did the various technicians not realise that this was a problem? were the astronauts rushed? were they careless? FrankSier (talk) 14:15, 15 October 2024 (UTC)

I suggest you consult the link above and come up with a brief summary. From what Alan Bean said, they only trained with a block of wood substituting for the camera and were not told that pointing it at the sun would block it out.

I agree, it is a major, major mistake. I read somewhere a theory that not being able to follow along on TV basically decimated public interest in the Apollo project. Wehwalt (talk) 14:21, 15 October 2024 (UTC)

It was more a failure of mission planning that practically set Bean up for failure. But of course, we need a reference that explicitly talks about the causes and effects. Otherwise, all we can say is that it happened.  Stepho  talk  18:30, 17 October 2024 (UTC)

It is absolutely true that no TV really snuffed out interest in the Apollo moonwalking. For the next mission, the 'star-crossed' Apollo 13, the 3 networks didn't even cover the outward trip where the explosion happened. Bill in L.A. 2603:8001:8043:2E6E:322E:B5AE:D82D:51AA (talk) 06:24, 26 August 2025 (UTC)

Non-sequitur. Lack of Apollo 12 moonwalk video doesn't mean lack of interest in Apollo 13 in-flight video. If the public was truly interested in Apollo at all then the lack of video in Apollo 12 would make them want it in Apollo 13 even more. Instead, the public went "meh - already done that, what's the next fad to watch" and that was duly filled in with the 13 disaster. After that, TV ratings slipped down again. In either case, we're both just armchair philosophising - we would need supporting references to support such claims.  Stepho  talk  00:50, 27 August 2025 (UTC)

Could someone add info on the Saturn V 3rd stage?

Did the Saturn V 3rd stage from Apollo 12 return near earth in 2002, and will it again in the future? Can someone add content on this? I don't know enough to do so. Locarno (talk) 14:54, 6 August 2026 (UTC)

It's in the already-linked J002E3 article. (— 𝐬𝐝𝐒𝐝𝐬 — - talk) 15:34, 6 August 2026 (UTC)

Nude photographs in the cuff checklists

I think this article should mention Reagan Wilson and the "playboy prank" (compare Talk:Reagan Wilson#Wilson on the Moon and Reagan Wilson#Life and career), but I'm not sure how. For the prank itself, see Conrad's checklist (pages 6 and 11), and Bean's checklist (pages 7 and 11). There is a photo of Pete Conrad on the surface with Wilson's photograph (barely) visible on his wrist. According to Fishman (cited in Wilson's article, see there for details), this was the photograph that Wilson had framed and put on the wall at his home, not realizing for years that Wilson was in it. Renerpho (talk) 04:57, 24 August 2026 (UTC)

Isn't it already on the page, I seem to recall it being so (removed by someone or am mistaken and saw it somewhere else). In any case, agree that this should be mentioned, for historical purposes of the events of early Moon exploration. Randy Kryn (talk) 05:34, 24 August 2026 (UTC)

I haven't read the entire article, but I've looked for mentions of "playboy", "prank", "cuff", "checklist", "Wilson", "nude" and "topless", and found nothing relevant. I wasn't aware of it until I read about it today on the Main Page. Renerpho (talk) 05:45, 24 August 2026 (UTC)

@Randy Kryn: It was removed in Special:Diff/1003175018 (27 January 2021) as irrelevant. I don't think I agree with that. Renerpho (talk) 05:52, 24 August 2026 (UTC)

Ha, so I did recall correctly from back in the dark ages when people were hiding in their homes from each other. Let's put it back, as the relevance of both the joke and the use of the individual's photograph during the second crewed Moon landing seems quite notable. Thanks. Randy Kryn (talk) 05:55, 24 August 2026 (UTC)

Agreed, and I think Fishman (2019), page 283 should be added as an independent source. The discovery that one of the nude photographs is visible in the photo that was taken on the Moon may have been due to Fishman. Renerpho (talk) 05:57, 24 August 2026 (UTC)

I'm not seeing the photograph in the Conrad photo, can't make it out at least. But the fact that the prank went as far as it did (236,000 miles or so) does deserve a return to the page after an over five-year hiatus. Randy Kryn (talk) 06:09, 24 August 2026 (UTC)

@Randy Kryn: Here's a side-by-side comparison of the checklist on his wrist (turned 90°) and the scan of the page: https://www.flickr.com/photos/198438449@N05/55484460894 Renerpho (talk) 06:19, 24 August 2026 (UTC)

Thanks. I know it was there, just that the camera used to photograph Conrad seems to be worse than the cheapest cell phone cameras nowadays. The Conrad photo probably shouldn't be used to illustrate the Wilson photo as you have to know it was there from knowledge and not by viewing the picture. In any case, returning Wilson to Apollo 12 is a noble and praiseworthy task, an episode in Moon lore worthy of legend and song, thanks for putting attention on the topic. Randy Kryn (talk) 06:27, 24 August 2026 (UTC)