My grandad was a part of the Apollo Flight Plans Group as a programmer

This week in the third grade at Amigos Por Vida, the kids are learning about space and the solar system. As a math and science teacher I tend to find connections between the topics. Working in space or even learning about space requires an understanding of math. Astronauts use math in order to make precise calculations from how the spacecraft leaves the Earth’s atmosphere to how the astronauts pilot the spacecraft. Even the designers use math to calculate the distance, velocity, and speed.

I have found this topic to be very interesting to teach as my grandfather was a part of the Apollo Flight Plans Group as a programmer back in 1963 at NASA’s Johnson Space Center. I have spoken with him this week about our lesson. Here is what he had to say about his time working there:


“In 1963, when I arrived to work at the Johnson Space Center, Building #30 for the Control Center was still under construction. About 60 computer programmers with one big computer worked writing programs the Apollo Project would need. We began in a converted warehouse on the Gulf Freeway. The night before President Kennedy was shot, he stopped there. He wanted to be the President who put the first man on the moon. I was assigned to the Apollo Flight Plans group of five programmers whose task was to create the fastest program we could to compute the ballistic flight path of the Apollo spaceship as it moved thru the Earth-Moon field. There are no simple equations to compute the flight path. The program must “integrate” numerically the effects of the gravitational forces acting on the spaceship as it moves away from Earth and approaches the Moon. A German named Encke had figured out a way to do that more than a hundred years before but he did it taking months with pencil and paper. Computers were really slow in the 1960’s compared to now. So the biggest part of our job was figuring out a whole lot of short cuts to reduce the amount of computing we had to do. We were standing on the shoulders of earlier scientists like Newton and Kepler and Encke. We, or at least I, didn’t really understand that Einstein had shown that Newton was wrong because for our purposes, Newton was good enough. Anyway when we finished, we could compute the flight path from the point where the rocket injects the spaceship from a “parking” orbit around earth, to the point behind the moon known as pericynthion, which is where the rockets would fire up again to put the spaceship into a lunar “parking orbit” – and we could do that with an accuracy of about one nautical mile. We were very happy with that accuracy and because it was the fastest integrator available, NASA decided to use it as a standard throughout the Apollo project for real time orbit prediction as well as in simulation training. I still have a copy of the Memo NASA issued announcing that decision because they called it the “Crane Integrator”. I really enjoyed the time that I worked in Building 30 and the Control Center but by the time NASA put a man on the moon, I had moved on to other work. You can be sure I stayed up worried for that event.”


Hopefully one day I can get him to come to APV to speak a little more on his experience.