I recently started listening to a fantastic podcast called 13 Minutes To The Moon[0] produced by the BBC. It’s a retelling of the last 13 minutes until the Apollo 11 lander touched down. Episode 2 talked about the software and the 1202 program code. They interviewed the Guidance controller who was only 26 at the time and talked about how the average age of the flight controllers was 27. I thought that was incredible, you don’t see that much responsibility placed in such junior people anymore.<p>[0] <a href="https://www.bbc.co.uk/programmes/w13xttx2" rel="nofollow">https://www.bbc.co.uk/programmes/w13xttx2</a>
CuriousMarc's Apollo Guidance Computer (AGC) restoration is a must-watch: <a href="https://www.youtube.com/watch?v=2KSahAoOLdU&list=PL-_93BVApb59FWrLZfdlisi_x7-Ut_-w7" rel="nofollow">https://www.youtube.com/watch?v=2KSahAoOLdU&list=PL-_93BVApb...</a>
There is a good book on the computer systems of Apollo project: Digital Apollo <a href="https://mitpress.mit.edu/books/digital-apollo" rel="nofollow">https://mitpress.mit.edu/books/digital-apollo</a><p>It describes interesting questions that were faced on the project: say, how much control over a lunar module could be given to a computer system, and how much they should rely on human engagement.
Best quote in the excellent article:<p>“You can’t get a degree in how to fly to the moon,” says Dana Densmore, who joined the lab in 1965 and became a control supervi-sor for the lunar-lander software. “You had to get people who know how to think, who are creative and alert. It was all in-vented on the spot.”
Kind of off topic, but for those interested, this reminded me of the public repo on github which has the original guidance computer source code for the command and lunar modules[0].<p>[0] <a href="https://github.com/chrislgarry/Apollo-11" rel="nofollow">https://github.com/chrislgarry/Apollo-11</a>
This is the best description of AGC I have seen so far, from hardware design to mission software, layer by layer: "The Ultimate Apollo Guidance Computer Talk" <a href="https://www.youtube.com/watch?v=xx7Lfh5SKUQ" rel="nofollow">https://www.youtube.com/watch?v=xx7Lfh5SKUQ</a>
If anyone wants to learn more about the Apollo Guidance Computer, this talk[1] from 34C3 will teach you everything you wanted to know and more.<p>The AGC had some really fascinating features for the time, including a cooperative multitasking system, interrupt driven IO, and even a virtual machine for doing linear algebra!<p>[1]<a href="https://youtu.be/xx7Lfh5SKUQ" rel="nofollow">https://youtu.be/xx7Lfh5SKUQ</a>
I knew a retired couple near where I lived growing up who, I found out later, were software programmers on the Apollo Program. Quite possibly worked in that lab. The husband passed away soon afterwards, and I never got around to asking the wife about her experiences (they both worked for the program!). But it was really cool reading about how the core software was written.
I've been listening to "13 minutes to the Moon" from the BBC recently. <a href="https://www.bbc.com/news/science-environment-48232627" rel="nofollow">https://www.bbc.com/news/science-environment-48232627</a><p>One part jumped out at me as brilliant especially for the time: when the computer was overloaded with tasks during the decent, it switched off all non-essential extras like screen displays in order to free up processing power. After that it shed even more to focus on only plotting the landing!
Fastcompany published a similar article about the 4th crew member of Apollo 11 a few weeks ago. I shared it on HN but it did not get any traction.<p><a href="https://news.ycombinator.com/item?id=20173672" rel="nofollow">https://news.ycombinator.com/item?id=20173672</a>
The article mentions the overload on the computer was caused by "a mismatched power supply to a radar" triggering too many calculations. Any idea how or why the power supply was mismatched ? Luckily software saves the day but what was the root cause of the hardware fault ? Was that a case of a mismanaged change in configuration ?
"The Charming Genius of the Apollo Guidance Computer" is a wonderful talk: <a href="https://www.youtube.com/watch?v=xY45YE7ggng" rel="nofollow">https://www.youtube.com/watch?v=xY45YE7ggng</a><p>The AGC implemented a virtual machine to run higher-level computational routines. The whole architecture is really interesting.
> When it came to hiring women for engineering or management, NASA “had a few women, and they kept them hidden,” says Ms. Densmore. “At the lab it was very different,” and there were opportunities for women.<p>Quite amazing what an important role women like Margaret Hamilton played in the Apollo project, given how hard it is nowadays to get more women into engineering positions. You may remember the famous picture of Hamilton next to the stack of code she and her team wrote for Apollo: see <a href="https://en.m.wikipedia.org/wiki/Margaret_Hamilton_(software_engineer)" rel="nofollow">https://en.m.wikipedia.org/wiki/Margaret_Hamilton_(software_...</a>
“You can’t get a degree in how to fly to the moon,” says Dana Densmore, who joined the lab in 1965 and became a control supervi-sor for the lunar-lander software. “You had to get people who know how to think, who are creative and alert. It was all in-vented on the spot.”
This contains more technical information behind the 1202 alarms [0]. It is an awesome read.<p>[0] <a href="https://www.hq.nasa.gov/alsj/a11/a11.1201-pa.html" rel="nofollow">https://www.hq.nasa.gov/alsj/a11/a11.1201-pa.html</a>
> MIT received the first major Apollo contract, the only one awarded to a university, and the only one given without competitive bidding.<p>Do these kinds of mission-critical components generally go to the lowest bidder?
Neat story but is the software really hidden? I feel like I have heard this story many times. It was one of the many feats of the Apollo program, I don't think I would consider it hidden.