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On This Day–Apollo 11 Day 4

19 July 1969, it is day 4, it has been 62 hours since launch, Columbia is now only 32,000 nautical miles from the Moon. They are traveling at a speed of 3782 feet per second. Houston has noted that the velocity has picked up in the last 50 minutes as the Columbia accelerates as it gets closer to the Moon. There was a mid course correction burn scheduled but mission control decided that the flight was right on and was dispensed with. So the crew was allowed an extra 2 hours sleep. While the Astronauts were sleeping, The behind the scenes action was 24/7 in Houston, as the Columbia is quickly approached the moon, now only 22,952 nautical miles.

Katherine Johnson, mathematician, has worked with the space program since the 50’s starting with NACA (National Advisory Committee of Aeronautics) which became NASA in 1958. Her team called the West Coast computers did complex mathematical calculations for program engineers. These computations were critical for the early success of the fledgling space program. It was her team that calculated where and when to launch the rocket for Apollo 11. Brilliant woman.

Frances “Poppy” Northcutt started work as a computress with TRW, a contractor for NASA. She stated on the Gemini program in 1965. But soon found herself on the lunar manned moon mission project to the moon and more importantly back again to earth. Though the job was to take the male engineers work and run calculations on them. All done by hand, computers at the time were quite clunky, required reams of paper punch cards and attention to slight detail. To make sense of the numbers she crunched, she wanted to know what the calculations meant. So she would ask questions.

Learning the process, she soon became an engineer herself. She calculated the return to earth trajectories starting with Apollo 8. Her calculations worked and soon found herself as a member of the technical team and in mission control. It was her calculations that were used for Apollo 11 for their return home from the Moon. Imagine that.

Margaret Hamilton, software engineer, wrote the software used on Apollo 11. Hamilton led the software engineering division at MIT. She took the lead to write the software that govern the flight dynamics for the Apollo spacecraft. Which were used for 6 Apollo landing missions from 69-72.

One of her earlier accomplishments was designing the software for SAGE (Semi-Automatic Ground Environment Air Defense System). This was the first air defense for the country. Wow. She helped push for digital computing in the 50’s and 60’s. This woman was thinking of the future.

At 71 hours the crew is awaken and will have breakfast, Aldrin suggests that we can eat and perform procedures at the same time. LOI (lunar orbit insertion) is performed, thats configuring the Columbia to a vector towards the landing site, as well when orbiting around the moon.


Almost there! 35 hours eta on landing on the surface,

1 additional image. Click to enlarge.


17 responses to On This Day–Apollo 11 Day 4

  1. Fascinating stuff – I remember we got a color-TV in preparation for the landing (in B/W). It was so great to follow then, and really interesting to re-visit today! Thank you for sharing.

    • Thanks Eric, we saw the whole thing play out on B/W tv. The teachers were talking about it in school. Kids sitting around in playground chatting as well. Don’t remember any other event during those year that brought so much interest as what was going with that moon shot.

  2. Fantastic Chuck!

    Incredible selection of material! It is a mammoth effort and I’d imagine everyone on here is loving it. I surely am – and my y7 class are mad for it!

    The kids looked at the approach today in class! I won’t see them again until Tuesday – we will have loads to catch up. They are almost bursting! Thank you for these posts!

    • Hi Paul, that seems to be the general consensus, fantastic! It was and still is an amazing achievement. The behind the scenes prior to the missions. This has never been done before, yet with all the testing, they did it. Hopefully inspiring future Astronauts and explorers for the final frontier!

  3. Once again, great stuff. The PBS series, Chasing the Moon, has some interviews and footage with Miss “Poppy” Northcutt…..very determined young lady.
    We’ll all hold our breath tomorrow and see if Armstrong and Aldrin do it again…..
    Thanks, Chuck.

    • Hi Gary, yeah she was quite cocky, but thats the right stuff for a woman among men, and though there was the typical tension with her colleagues, she was able to overcome that light harrassment. And it was more like verbal nothing serious. As everyone had only one thing in mind. Not only get the astronauts to the Moon, but bring them back home to Earth safely. She was brilliant. I am looking forward to the replay, quite inspirational.

  4. Great info, Chuck! Keep it coming.We had another event of interest here in 1969,while not as significant, The N.Y. Mets one the world series.

    • Robert, Being a fellow New Yorker (upstate) the other memorable event stuck between Apollo 11 and the Amazin’ Mets was Woodstock, in Bethel, Ny, 20 mins from my hometown. My Mom, sister and neighbors drove over the day after it was over and this year I’m going back to see Santana.
      I’ve been a lifelong Yankee fan but you can’t not like the 69 Mets. What a pitching staff, Seaver, Koosman, McGraw and a little known rookie, Nolan Ryan.
      Good stuff!

      • 1969 was a year that not only ended the decade, but quite a few significant events happened right off the bat in January with the swearing in of President Nixon, don’t forget it was a banner year for NY. As the Jets won the Super Bowl with Broadway Joe Namath, not just the Miracle Mets later on in October win the World Series. Here in LA we are dealing with riots in S. Central sharing dark moments with Chicago. As NY was enjoying a great year, we were dealing not only the riots but also the Manson murders, So there was good and bad going on in 69.

  5. Very well done and nice to recognize the women that were such an important part of the space program.

    • Thanks Wayne, they were remarkable and extremely intelligent. We don’t give them enough credit. And there are more of them that did some very important if not critical contributions to the program. I just listed these 3 to just get a feel in how important they were.

  6. Another brilliant post. I am so pleased to see you take up the mantle of ‘On This Day’, Chuck, and especially so giving such a great analysis of one of our most historically significant moments and greatest achievement.

    Wonderful reading, and beautiful images.

    ‘Liked’

  7. Thanks, Chuck. Regardless of it ‘just being one subject’ it’s a great addition to the canon. Maybe you will start a trend, Chuck.

    Thanks my friend.

    @uscusn

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