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Uh. There's so much wrong in that article that it hurts. Can't people actually research history more seriously?

by jakub_h 11y ago

GFK_of_xmaspast 11y ago
Such as?
- jakub_h 11y ago
  Have you read Digital Apollo by Dave Mindell? If not, do so. It is a much better researched text on the story of Apollo guidance, by a professor of aerospace history who works at the institution (MIT) formerly involved with AGC. In the meanwhile, the text at http://www.doneyles.com/LM/Tales.html http://www.doneyles.com/LM/Tales.html will de-disinform you with regards to some of the article's mistakes.
  - GFK_of_xmaspast 11y ago
    I just skimmed that but I don't see anything there that would contradict the original post.
    - jakub_h 11y ago
      What about the claim about the actual cause of the Apollo 11 program alarms? What about the involvement of Hal Laning in the actual design and implementation of the real-time executive casually attributed to Hamilton in this article and some of the others on the web?
      - GFK_of_xmaspast 11y ago
        They both appear to claim that the alarms were caused by too-heavy processing loads: " This was the action taken by the Executive program if its resources were exceeded. If a job could not be scheduled because no "core sets" were available, the Executive called BAILOUT with alarm code 1202. If no "VAC areas" were available, BAILOUT was called with alarm code 1201." vs "The result was that the computer was being asked to perform all of its normal functions for landing while receiving an extra load of spurious data which used up 15% of its time. The computer (or rather the software in it) was smart enough to recognize that it was being asked to perform more tasks than it should be performing. It then sent out an alarm, which meant to the astronaut, “I’m overloaded with more tasks than I should be doing at this time and I’m going to keep only the more important tasks; i.e., the ones needed for landing.” " Hamilton claimed in 1971 that "Due to an error in the checklist manual, the rendezvous radar switch was placed in the wrong position", Eyles says "The problem has also been attributed (including by the author previously) to a "checklist error". Also if you're going to point out that the Medium article doesn't mention Laning, it seems equally damming that Eyles doesn't mention Hamilton.
        jakub_h 11y ago
        I was talking about the root cause, not about the symptoms. The article claims that the alarms were caused by a "checklist error", when in reality, it was an analog interface mismatch caused by incomplete specification which two different teams interpreted sufficiently differently to cause a hard-to-debug hardware problem. If Eyles doesn't mention Hamilton, it's probably because she wasn't involved in the particular functionality of the Apollo software that is being ascribed to her by many articles on the Internet and that is relevant to the Apollo 11 incident. In this particular article, it's not claimed explicitly by the author, but it is insinuated by the statement "I read that the Apollo would not have been able to land without your software." Well, of course, if she was a team lead on the software effort, the whole software is "hers" from a certain point of view, but that's sort of like giving whole credit to Bill Gates for writing Microsoft Windows. Mindell does mention her on several occasions, but in the software resilience area, he connects her to rigorous checking and prevention of erroneous user inputs, not to executive fault-tolerance. This functionality has proven critical on at least one occasion (when Apollo 8 astronauts mistakenly attempted to initiate pre-start sequence in mid-flight) but not in the incident in question.

Uh. There's so much wrong in that article that it hurts. Can't people actually research history more seriously?

by jakub_h 11y ago

Uh. There's so much wrong in that article that it hurts. Can't people actually research history more seriously?

GFK_of_xmaspast 11y ago

Such as?

jakub_h 11y ago
Have you read Digital Apollo by Dave Mindell? If not, do so. It is a much better researched text on the story of Apollo guidance, by a professor of aerospace history who works at the institution (MIT) formerly involved with AGC. In the meanwhile, the text at http://www.doneyles.com/LM/Tales.html http://www.doneyles.com/LM/Tales.html will de-disinform you with regards to some of the article's mistakes.
- GFK_of_xmaspast 11y ago
  I just skimmed that but I don't see anything there that would contradict the original post.
  - jakub_h 11y ago
    What about the claim about the actual cause of the Apollo 11 program alarms? What about the involvement of Hal Laning in the actual design and implementation of the real-time executive casually attributed to Hamilton in this article and some of the others on the web?
    - GFK_of_xmaspast 11y ago
      They both appear to claim that the alarms were caused by too-heavy processing loads: " This was the action taken by the Executive program if its resources were exceeded. If a job could not be scheduled because no "core sets" were available, the Executive called BAILOUT with alarm code 1202. If no "VAC areas" were available, BAILOUT was called with alarm code 1201." vs "The result was that the computer was being asked to perform all of its normal functions for landing while receiving an extra load of spurious data which used up 15% of its time. The computer (or rather the software in it) was smart enough to recognize that it was being asked to perform more tasks than it should be performing. It then sent out an alarm, which meant to the astronaut, “I’m overloaded with more tasks than I should be doing at this time and I’m going to keep only the more important tasks; i.e., the ones needed for landing.” " Hamilton claimed in 1971 that "Due to an error in the checklist manual, the rendezvous radar switch was placed in the wrong position", Eyles says "The problem has also been attributed (including by the author previously) to a "checklist error". Also if you're going to point out that the Medium article doesn't mention Laning, it seems equally damming that Eyles doesn't mention Hamilton.
      - jakub_h 11y ago
        I was talking about the root cause, not about the symptoms. The article claims that the alarms were caused by a "checklist error", when in reality, it was an analog interface mismatch caused by incomplete specification which two different teams interpreted sufficiently differently to cause a hard-to-debug hardware problem. If Eyles doesn't mention Hamilton, it's probably because she wasn't involved in the particular functionality of the Apollo software that is being ascribed to her by many articles on the Internet and that is relevant to the Apollo 11 incident. In this particular article, it's not claimed explicitly by the author, but it is insinuated by the statement "I read that the Apollo would not have been able to land without your software." Well, of course, if she was a team lead on the software effort, the whole software is "hers" from a certain point of view, but that's sort of like giving whole credit to Bill Gates for writing Microsoft Windows. Mindell does mention her on several occasions, but in the software resilience area, he connects her to rigorous checking and prevention of erroneous user inputs, not to executive fault-tolerance. This functionality has proven critical on at least one occasion (when Apollo 8 astronauts mistakenly attempted to initiate pre-start sequence in mid-flight) but not in the incident in question.