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.