Finally, if you are still with me, you hardy reader...
September 18, 2015 10:10 AM Subscribe
Tindallgrams is a collection of snarky memoranda of Howard W. "Bill" Tindall, Jr., a NASA Orbital Mechanics specialist working at MIT to coordinate software development for the Apollo spacecraft guidance systems. His memos, dating from 1966 through 1970, are epistles of triumph, frustration, and incomprehension that will be familiar to project managers throughout time.
Tindall dealt with changing mission constraints, feature sets, and timelines; tug-of-war with outside dependencies; internal struggles for technical accomplishment; hardware being inadequate for the software and vise versa.
A couple of highlights:
I really blew it at the June 5 Apollo Spacecraft Software Configuration Control Board meeting. (June 13, 1969, just 4 weeks before Apollo 11 was to be off the launchpad)
Subject: How to land next to a Surveyor - a short novel for do-it-yourselfers
There were some things about the terminal descent on the last mission that kind of spooked a lot of people.
But now I see they were right all the time and the rest of the world is nuts (Re: Spacecraft computer program names) That one signs off with "I’m serious, as usual."
Tindall dealt with changing mission constraints, feature sets, and timelines; tug-of-war with outside dependencies; internal struggles for technical accomplishment; hardware being inadequate for the software and vise versa.
A couple of highlights:
I really blew it at the June 5 Apollo Spacecraft Software Configuration Control Board meeting. (June 13, 1969, just 4 weeks before Apollo 11 was to be off the launchpad)
Subject: How to land next to a Surveyor - a short novel for do-it-yourselfers
There were some things about the terminal descent on the last mission that kind of spooked a lot of people.
But now I see they were right all the time and the rest of the world is nuts (Re: Spacecraft computer program names) That one signs off with "I’m serious, as usual."
"According to Ed Copps, all fixed memory of the computer is filled; and, in fact, it was necessary to take out about 500 words of the reentry program associated with super-orbital entry in order to make it fit. "
Those programs were lean.
posted by ocherdraco at 10:35 AM on September 18, 2015 [1 favorite]
Those programs were lean.
posted by ocherdraco at 10:35 AM on September 18, 2015 [1 favorite]
"Rope manufacture"? I have a guess on what it means, but does anybody know?
posted by benito.strauss at 10:36 AM on September 18, 2015
posted by benito.strauss at 10:36 AM on September 18, 2015
Software written by MIT programmers was woven into core rope memory...
posted by blue_beetle at 10:55 AM on September 18, 2015
posted by blue_beetle at 10:55 AM on September 18, 2015
Man, these are a lot easier to read than the massive PDF scans I have.
The thing about these that really jumps out at me is their depth and breadth of detail.
MPAD's (Mission Planning and Analysis Directorate) was to bring all the other things together. Because of that, they fundamentally had to understand the basics almost almost everything, and really had to know the guidance systems cold, since PNGS and AGS would fundamentally run the mission.
And, of course, since they were Mission Planning, they were in charge of the Mission Rules, which meant they had to know ever step of the mission.
This meant they were they synthesists of the program. The guys who were brilliant at one thing ended up in other places. You had to be able to handle everything in MPAD.
Bill Tinadall's gift was just that, plus known when he wasn't and instantly passing that off to someone who did and accepting the answer as gospel, plus a communication style that made everybody glad to work with him. So, a ton of information flowed to him, he made it flow out again. And, as it did, he noticed lots of things.
One famous thing he did -- NASA's famous call is "go". He changed that, the most famous word in spaceflight, the word that is NASA, and when he did, everyone saw it and agreed he was right, it had to be changed there.
His question. When we land on the moon, what does "go" mean?
So, when Apollo 11 became Tranquility Base, Gene Kranz polled his team. And, instead of that famous word, they instead used Bill Tindall's word.
"Stay." And Neil and Buzz stayed on the moon.
Tindall realized that in that case, Go meant Stay and No Go meant Go, and if you needed to LEAVE RIGHT NOW, that might kill your astronauts. So that call -- that one call -- is simple. On the question of remaining in place, the call is STAY/NO STAY.
Otherwise? All things are GO.
Countless times, Tindall spotted things like that and said "let's smooth that point." And when he wrote those memos, which could have been eaisly "THIS IS BAD AND YOU SHOULD FEEL BAD" everybody read them, chuckled, and went, "well, hell, Tindall's right again. Yeah, that makes a bunch of sense. Let's do that" -- even the guy who'd suggested the bad thing was happy with the change.
He was a comedian, a diplomat, a steely eyed missile man, and a hell of an engineer. If I end up being a tenth of a guy Bill Tindall was, I'm calling my life a huge success.
posted by eriko at 11:09 AM on September 18, 2015 [28 favorites]
The thing about these that really jumps out at me is their depth and breadth of detail.
MPAD's (Mission Planning and Analysis Directorate) was to bring all the other things together. Because of that, they fundamentally had to understand the basics almost almost everything, and really had to know the guidance systems cold, since PNGS and AGS would fundamentally run the mission.
And, of course, since they were Mission Planning, they were in charge of the Mission Rules, which meant they had to know ever step of the mission.
This meant they were they synthesists of the program. The guys who were brilliant at one thing ended up in other places. You had to be able to handle everything in MPAD.
Bill Tinadall's gift was just that, plus known when he wasn't and instantly passing that off to someone who did and accepting the answer as gospel, plus a communication style that made everybody glad to work with him. So, a ton of information flowed to him, he made it flow out again. And, as it did, he noticed lots of things.
One famous thing he did -- NASA's famous call is "go". He changed that, the most famous word in spaceflight, the word that is NASA, and when he did, everyone saw it and agreed he was right, it had to be changed there.
His question. When we land on the moon, what does "go" mean?
So, when Apollo 11 became Tranquility Base, Gene Kranz polled his team. And, instead of that famous word, they instead used Bill Tindall's word.
"Stay." And Neil and Buzz stayed on the moon.
Tindall realized that in that case, Go meant Stay and No Go meant Go, and if you needed to LEAVE RIGHT NOW, that might kill your astronauts. So that call -- that one call -- is simple. On the question of remaining in place, the call is STAY/NO STAY.
Otherwise? All things are GO.
Countless times, Tindall spotted things like that and said "let's smooth that point." And when he wrote those memos, which could have been eaisly "THIS IS BAD AND YOU SHOULD FEEL BAD" everybody read them, chuckled, and went, "well, hell, Tindall's right again. Yeah, that makes a bunch of sense. Let's do that" -- even the guy who'd suggested the bad thing was happy with the change.
He was a comedian, a diplomat, a steely eyed missile man, and a hell of an engineer. If I end up being a tenth of a guy Bill Tindall was, I'm calling my life a huge success.
posted by eriko at 11:09 AM on September 18, 2015 [28 favorites]
eriko: Man, these are a lot easier to read than the massive PDF scans I have.
Only some of them are available as HTML: others have links to PDFs, but most appear in more than PDF, making it more likely that there is a readable copy.
eriko:Tindall realized that in that case, Go meant Stay and No Go meant Go, and if you needed to LEAVE RIGHT NOW, that might kill your astronauts. So that call -- that one call -- is simple. On the question of remaining in place, the call is STAY/NO STAY.
I had to read this several times before realising that the ambiguity is in communicating about whether to remain on the moon or take off immediately after landing, rather than at the time it was planned to leave the moon; the question was then asking whether everyone was happy to continue with the mission on the moon's surface ('GO' with the mission, but 'STAY' on the moon) , rather than whether they were happy to take-off ('GO' with the take-off, and also 'GO' from the moon).
Tindall's precise suggestion was:
posted by James Scott-Brown at 12:35 PM on September 18, 2015 [3 favorites]
Only some of them are available as HTML: others have links to PDFs, but most appear in more than PDF, making it more likely that there is a readable copy.
eriko:Tindall realized that in that case, Go meant Stay and No Go meant Go, and if you needed to LEAVE RIGHT NOW, that might kill your astronauts. So that call -- that one call -- is simple. On the question of remaining in place, the call is STAY/NO STAY.
I had to read this several times before realising that the ambiguity is in communicating about whether to remain on the moon or take off immediately after landing, rather than at the time it was planned to leave the moon; the question was then asking whether everyone was happy to continue with the mission on the moon's surface ('GO' with the mission, but 'STAY' on the moon) , rather than whether they were happy to take-off ('GO' with the take-off, and also 'GO' from the moon).
Tindall's precise suggestion was:
Before delving into these major items, there are a couple of other things I would like to mention. The first may seem trivial. It deals with terminology - specifically, use of the expression "go / no go" regard- ing the decision whether to stay or abort immediately after landing on the lunar surface. Every time we talk about this acitivity we have to redefine which we mean by "go" and "no go." That is - confusion inevitably arises since "go" means to "stay" and "no go" means to "abort" or "go." Accordingly, we are suggesting that the terminology for this particular decision be changed from "go / no go" to "stay / no stay" or something like that. Just call me "Aunt Emma".Memo 69-PA-T-42A, "G Lunar Surface stuff is still incomplete"
posted by James Scott-Brown at 12:35 PM on September 18, 2015 [3 favorites]
You can hear the STAY/NO STAY from Apollo 11, set to music, in this bit from "Go!" a song from the British duo Public Service Broadcasting. (It is immediately followed by the song's 'chorus,' which is a Go/No Go call from earlier in the mission.)
I think you should listen from the beginning-- this is only about my 5th or 6th time linking to this band in the space-sounds-related threads on MeFi.
posted by Sunburnt at 1:59 PM on September 18, 2015 [8 favorites]
I think you should listen from the beginning-- this is only about my 5th or 6th time linking to this band in the space-sounds-related threads on MeFi.
posted by Sunburnt at 1:59 PM on September 18, 2015 [8 favorites]
Some deets on the computers and software aboard the Apollo spacecraft.
posted by RobotVoodooPower at 2:24 PM on September 18, 2015 [1 favorite]
posted by RobotVoodooPower at 2:24 PM on September 18, 2015 [1 favorite]
Some deets on the computers and software aboard the Apollo spacecraft.
That is a great read. You always hear how the Apollo flights had "about as much computing power as a pocket calculator," but it was great to finally see it in MHz. (0.043 MHz to be exact).
posted by Brodiggitty at 7:09 PM on September 18, 2015
That is a great read. You always hear how the Apollo flights had "about as much computing power as a pocket calculator," but it was great to finally see it in MHz. (0.043 MHz to be exact).
posted by Brodiggitty at 7:09 PM on September 18, 2015
I've been spending my morning writing documentation for my department that includes the phrases, "This is slow and kinda dumb but it works and that's really what matters, don't you agree dear reader?" "Lo! A new wrinkle has occurred! How do we sift all this meaningless crapola for the one port we need?" as well as "Success! It's broken on purpose after all!"
I've found my new patron saint.
posted by endotoxin at 10:39 AM on September 19, 2015 [2 favorites]
I've found my new patron saint.
posted by endotoxin at 10:39 AM on September 19, 2015 [2 favorites]
Saint Tindall, the Patron Saint of Project Managers, who performed 8 miracles that sent 24 men to the moon and brought them home safely.
posted by Sunburnt at 6:21 PM on September 20, 2015 [2 favorites]
posted by Sunburnt at 6:21 PM on September 20, 2015 [2 favorites]
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posted by hearthpig at 10:34 AM on September 18, 2015