Lance Drane began his time working in computer science at the Instrumentation Lab in 1965. He worked on the mainframes and the simulation for the Apollo Guidance Computer. Not only did they have to program the simulations, but he and his colleagues had to write the operating systems to run the simulations from the ground up. Starting with the Saturn V rocket, they modeled the way the spacecraft would be affected by things like gravity as it flew toward the moon. These simulations were integral to how they understood the flights and how the team dealt with unexpected mid flight errors.
Every bit of the AGC programming was done on punch cards, and any errors would take days to discover. With only a certain amount of memory on the Apollo computer, there had to be a failsafe in place for the commands that were the most important to take over, as evidenced by the 1202 alarms on Apollo 11. When it came to the explosion of Apollo 13, Drane and his team had written software to ensure that somehow the Lunar Module would be able to push (or “burn”) the other modules into the correct trajectory should the Module lose some power. Although it had not been tested extensively, the three days it took for Apollo 13 to re-enter were incredibly tense for everyone involved.
Drane looks fondly back on his days working on the program and continues to work for Draper.