Light Years Ahead | The 1969 Apollo Guidance Computer

[double_barrel]

I thought this might be of interest to you lot

https://www.youtube.com/watch?v=B1J2RMorJXM

[wiggy]

Very interesting., many thanks for that..

I'm just slightly :hmm: at the emphasis or perhaps the impression the speaker tries to create that Aldrin was perhaps being a bit naughty and tipped the AGC over the edge by asking the computer for unnecessary info ( the "16 68" discussion).

The request by Aldrin may well have been last straw for the machine which was already struggling with a hardware bug but somebody did need to monitor at least one of the variables that entering "16 68" caused to be displayed, specifically the "delta H" - the difference between inertially computed height and landing radar sensed height.

There's certainly never been any hint in the histories/debrief transcripts/documentation I've read that Aldrin was calling for anything unnecessary from the AGC, he was operating iaw with planned procedures but using their initiative Mission Control took over the task with a call of "we'll monitor your delta-H".

The big big problem and the root cause of the alarms which gets a minor mention in the youtube video was the "hardware bug" introduced by the Rendezvous Radar.

There's quite a good description of the problems here:

Don Eyles...LM Tales..(about half way down the paper) (https://www.doneyles.com/LM/Tales.html)

more mainstream account here:

https://arstechnica.com/science/2019/07/no-a-checklist-error-did-not-almost-derail-the-first-moon-landing/

[Nige321]

Bringing an AGC back to life... (https://www.wsj.com/articles/an-apollo-spacecraft-computer-is-brought-back-to-life-11563152761)
or
Run it on your iPad... (http://www.airspayce.com/airspayce/dsky/)

[tartare]

Really interesting presentation.
And no doubt when Artermis goes back - it'll all just be magenta lines on a huge EFIS.
Just like a giant video game...

[Jhieminga]

I was unable to open the Wall Street Journal link, but after a bit of Googling found the Youtube videos that show the entire restoration as well as other related AGC topics: https://www.youtube.com/playlist?list=PL-_93BVApb59FWrLZfdlisi_x7-Ut_-w7
Warning... it will cause you to lose track of time...