Apollo Comms Part 34: Trying every function of the Apollo command system

We finally have our Apollo command system all working! Let's understand and try every function so we can hack the Apollo spacecraft the next time they launch it...
Apollo Comms Playlist: • Apollo Comms Part 1: O...
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[@aserta]

You know... we used to joke you guys will bring back the program one part at a time... but man. The more you guys dig, the more i think you should receive a blank cheque and all the manpower you can muster...

[@wackyvorlon]

It is amazing and incredibly important work. Preserving a key part of Apollo history that is far too often overlooked.

[@projectartichoke]

Marc does these things not because they are easy... 😁

[@graemedavidson499]

I’m still in awe at how all this was developed and executed. The forethought and implementation is astounding! Congratulations to your team for figuring it all out and getting it working.

[@MarcelHuguenin]

Wow, another awesome episode to behold. Together you guys are a real dream team. I find it so fascinating you are able to reverse engineer all of this tech and understand the thinking of that time on the how and why. Thank you so very much Marc and team, it was really entertaining.

[@hymermobiler]

Thanks for another 37 minutes of genius

[@AL6S00740]

Just imagine. All these things , man made. I kudos everyone , and thank you Mark for showing us the "remote desktop" version of Apolo. Thank you again !

[@projectartichoke]

Your videos are always so immensely enjoyable! Thanks so much for making them.

[@malcolmgibson6288]

Well worth the wait. What a great job you are doing.

[@realfoggy]

You and the crew are amazing. Great work!

[@rdwatson]

I laughed out loud at the absurdity of all that equipment just to turn a light on and back off... but love every minute of the entire Apollo comms series.

[@JustFamilyPlaytime]

Buttons and Blinkenlights! Great stuff.

[@kristofferlkke-srensen3982]

I thought you guys would never top the AGC restoration, but man was I wrong! This is absolutely astonishing! Both the work, foresight etc by the original engineers, but also you guys reverse engineering skills. I’m flabbergasted. What you are doing, is documenting the stone age of modern technology in a fascinating and modern way. Hats off to you - this effort is just amazing! 🎉

[@VE7QH]

In episode 100 I wouldn't be surprised if they just go ahead and rebuild an apollo capsule

[@ReneSchickbauer]

"Hello and Welcome. As you know, we have landed at the Apollo 15 site and are currently restoring the LRV communications system. In the last episode Master Ken has reverse-engineered the remote camera control circuits and Mike has written a transistor-level emulator of the uplink encoder..."

[@VE7QH]

@@ReneSchickbauer hahaha 😂

[@richardhole8429]

37 minutes of bliss. Thanks, guys, you made my day.

[@OleJanssen]

With some luck, CuriousMarc might actually put man back on the moon before NASA does.

[@mlann2333]

Incredible engineering for back in the day. Wow.

[@devrim-oguz]

It is crazy to think that you can fit all the gates in the AGC to a tiny FPGA. It is like the same computer but very smollll

[@twingoman2000]

love it! keep up the Work

[@berndeckenfels]

„So you have a highly complicated update system, what you use for most channels, must be really tricky functions“ „oh yes! Two different methods to turn on a warning lights!“ reality of spaceflight in Apollo age is equally mindblowing and ridiculous 😮 It beeps! No no we can make a muuuuch more impressive demo, look at that light!

[@beatrix_victoriastation]

Amazing work, thanks! The links are not encrypted, we didn’t have hackers then

[@nicksantos43]

Boeing should have hired you guys to rebuild an Apollo capsule instead of Starliner. Would have saved a lot of money on debugging.

[@zebo-the-fat]

Wonderful!

[@meerkatmcr]

On the schematics you've shown, there's a lot of symbols that look like a large Z with numbers in various places around it. They seem to be references to another drawing, somehow, but I don't quite see how. What do they mean? Thanks for bringing us all into your lab to see all these things you're so lucky to have to play with. Keep being awesome!

[@deathblowhere]

You are correct. It references to a sheet number and letter/digit sector on that sheet, which has that circuit, hope it makes sense :) Eg. Sheet number 6.5, sector A/3

[@meerkatmcr]

@@deathblowhere so the sheet numbers are split each side of the Z, and the sector (is that like a grid?) is underneath?

[@davidvoeller5811]

I was just typing this question as you referred ti the issue at the end. Did they actually use paper tape to upload commands? Hard to think they’d do that in real time to, eg, turning on that abort light.

[@benjaminhanke79]

No way, too much room for human errors. But I'm also curious.

[@CuriousMarc]

It’s complicated, I need to do another video on how that was done. But yes, you guessed right, Abort was from a button press that triggered a pre-recorded message right at the tracking site. A special priority one at that, that would interrupt any ongoing uplink.

[@gusbert]

I'm sorry if I am repeating a question, but were these diagrams and schematics hand drawn or plotted by an X-Y plotter? And those switches are really beautiful. I cannot express my respect for how much I admire the engineers, manufacturers and shop floor people who made the Apollo program possible.

[@CuriousMarc]

They look hand drawn. They are drop-dead gorgeous drawings. I’ll post the links when I have a minute.

[@medicman4444]

Yey new marc :3

[@yuppiehi]

The beginning of remote desktop....

[@darrenconway8117]

Over Engineering: Why make things simple when you can make them really complicated AND get them to work.

[@b.v.skijump432]

Out of curiousity. Is the agc on the pallet still kicking arround and is there a chance you can get it up and running?

[@sundhaug92]

5:41 what about the signals for the LV not being intact?

[@AsbestosMuffins]

ground control to major tom, your light is blinken, there's something wrong!

[@WilliamPetefish]

Out of curiosity, is the bitrate on the dsky presses from Houston limited to a human level or can it read as fast as it can be sent?

[@CuriousMarc]

Both. We’ll cover that in another episode, but when doing manual keypresses, flight controllers were supposed to wait for reading it back on their control screen DSKY telemetry return before pressing the next key. With the propagation delay both ways, that meant up to 3 seconds between keystrokes. When doing a ground computer assisted load, keystrokes were sent about 300 ms apart (take this with a grain of salt, I need to double check that figure), without waiting for confirmation, in order to go faster. However, the keystrokes were accumulated in a keystroke buffer in the AGC, and held there. At the end of the computer load uplink, which took 20s, the controller (and the ground computer) would both check the entire buffer content via telemetry. If it checked good, the FC (and not the computer) would enter “Verb 33 Enter” manually from the console, causing the AGC to accept the buffered load and process the keystrokes. So they were very cautious and deliberate with their AGC uploads.

[@kriss1_]

Almost as hard to set the space clock as the golang dateformat

[@andymouse]

Why does the DSKY have 'verb' and 'noun' or is this a real crappy question please ?

[@Broken_Yugo]

IIRC the two are sort of analogous to "instruction" and "data".

[@andymouse]

@@Broken_Yugo Makes sense now cheers friend :)

[@wackyvorlon]

Honestly, instead of straightening the shafts I would have just made new ones.

[@FenderSan]

hehe nerds

[@darrylr]

Click the like button #34. 🙂

[@puffthemagiclepton7534]

First!

[@realfoggy]

You most certainly are! I'm proud of you!

[@CuriousMarc]

You are first! If you turn on your AGC and put the UP TLM switches to the ACCEPT position, we’ll uplink you a congratulation message.

[@realfoggy]

@@CuriousMarc hahaha