Details of Apollo 11 video transmission

Question

NASA has the video of Neil Armstrong on the moon. I'm interesting in the technology how the signal was created and transmitted. There are some details about it in Wikipedia but I'd like to know in-depth. Could it be a feasible project for me to recreate the NASA technology using my own hardware and methods?

Or at least learn how it was done in detailed theory, electronically, physically and mathematically?

score 2 · Answer 1 · answered Dec 22 '16 at 03:31

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Their system was very proprietary. Here is an interesting historical note on that. When the "Great Step for Man" was taking place, the video was being displayed on a special monitor (while being recorded in the background.) The TV News crew could not process the direct signal, so they just pointed their cameras at the monitor. That grainy image shot off the screen is what everyone has seen. The original was much better.

But in a terrible bureaucratic faux pas, NASA not only never transcoded the original video, they accidentally ERASED it. That’s why the only surviving video is the grainy TV news video shot off NASA’s screen.

answered Dec 22 '16 at 03:31

Johnny Robinson

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That is so astonishing. I wonder who erased it and if that was a deliberate decision. – Niklas Rosencrantz Dec 22 '16 at 03:46
The original video tape was considered data, as all their other received telemetry. It went into a vault according to procedure along with mountains of other tape, where it sat for many years. It was indexed and could have been pulled and transcoded. But nobody thought of it. It was also normal for people to pull very old tape that had not been accessed to reuse. It eventually got recorded over. – Johnny Robinson Dec 22 '16 at 04:51
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A couple of websites which may be of interest: Apollo 11 Missing Tapes & NASA Restored Apollo 11 Moonwalk Video – Fred Dec 22 '16 at 06:05
Adding to @Fred's comment, https://moonscapemovie.blogspot.com/ may also be of interest. – user Dec 22 '16 at 14:56

score 1 · Answer 2 · answered Dec 21 '16 at 23:39

Could it be a feasible project for me to recreate the NASA technology using my own hardware and methods?

Sure, but beware the costs.

1960's cameras where impressive beasts, made from components (camera tubes) that no one uses these days anymore. To top this up, NASA certainly didn't just buy a stock TV camera and put a sticker on it, they certainly put thought into weight reduction and operation in space and with astronaut fingers...

Or at least learn how it was done in detailed theory, electronically, physically and mathematically?

I'd recommend you start out by studying electrical engineering, which is the theory of electronics, the physics behind electronic devices and the math behind practical signals.

If you have the basics of linear electrical networks down, it's probably worth taking a while to study signal theory, after which you turn to understanding tube devices (something that is not commonly taught these days anymore – tubes aren't used for these kind of things anymore, but are typically specialty devices for high-power microwaves etc).

Your signal theory will nicely prepare you for both understanding what the electrical signals coming out of the camera tube itself are, as well as understanding the basics of RF and RF communications.

A bit of self-study on legacy analog TV standards will probably be easy after that.

Then, you would probably be able to understand the functionaly of each (ok, most) components in such a camera in a detailed way.

If I recall correctly, the actual signal transmission was closer to slow-scan TV than to common NTSC or PAL TV transmissions. — user, Dec 22 '16 at 14:58
Well, yes, but a) look at the time line of ntsc development and b) to understand things like video transmission at that time, it pays to have an understanding of the technological possibilities, which nicely correspond to how the TV standards were written — , Dec 22 '16 at 21:39

Details of Apollo 11 video transmission

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