When those of us who weren’t yet born think about Apollo 11’s Moon landing on July 20, 1969, I think we imagine a nation waiting with bated breath for Neil Armstrong to emerge from the lunar module and set foot on the Moon’s surface.

But that wasn’t the part that captivated Southport summer resident Robert Stengel, who’s giving a talk about his role in the Apollo 11 Moon landing on Wednesday, Aug. 14, at 5:30 p.m. at the Boothbay Harbor Memorial Library.

When Stengel watched the landing from a conference room in Draper Lab in Cambridge, Massachusetts, he and his colleagues were riveted by the short stretch of time during which the Lunar Module that carried Astronauts Armstrong and Aldrin was piloted and landed manually by Armstrong.

Stengel had written the code that translated Armstrong’s controls into firing instructions for the module’s 16 steering rockets.

“That must have been stressful,” I asked Stengel.

“I know everyone was thinking, ‘I hope my part works.’ The last thing any of us wanted was for the thing we worked on to have a glitch.”

Of course there were no glitches, and the Lunar Module touched down on the surface of the Moon at 4:17 p.m. eastern time.

There were no problems with Stengel’s code because he had used his lab’s simulator many times before that day to check both the code’s accuracy and the responsiveness of the controls.

“Each time I landed on the Moon, we started the simulation at the point where the descent engine lit up to slow the lunar module,” Stengel explained. “It would take about 10 to 12 minutes from then until we got to the point where I could switch it over to manual. That’s when I could pretend that I was flying it.

“A lot of the time I was in the simulator it didn’t quite work like I wanted it to,” he recalled. Which I think is engineer-speak for there were plenty of simulated crash landings, but you’ll be able to ask him these kinds of questions at his talk next week.

Be sure to also ask him how he got his mother and wife to the Moon eight times. That’s got to be every man’s dream! Ha!

To further get in the mood for Stengel’s talk, we’ll show the 2019 documentary “Apollo 11” on the lawn at 8 p.m. on Friday, Aug. 9.

I didn’t see “Apollo 11,” but according to its Wikipedia page and the reviews I read, the really spectacular thing about this documentary is that there’s no narration, interviews, explanations, or recreated scenes. The documentary is composed entirely of archival footage.

It’s gotten wonderful reviews.

Interestingly, this will make the third summer in a row that we’ve shown a Moon landing movie. There was “Hidden Figures” last year and “Apollo 13” the year before that. I guess we’ll have to add Moon movies to our annual theme list (which currently includes Bill Murray movies, Disney movies, and Mel Brooks movies, in case you’re wondering how we choose what to show).