STEM early childhood systems thinking decision-making Apollo 11
I was sitting in the preschool garden on a Tuesday morning this week, watching six-year-old Maya try to coax a wilted zucchini leaf back to life with nothing but water and determination. She'd been at it for ten minutes. The other children had moved on to counting ladybugs, to comparing the size of pumpkin seeds, to the kind of gentle, drifting exploration that happens when you let four-year-olds set their own agenda.
Maya kept going. She wasn't wrong to try — she was just investing too much cognitive bandwidth into a single task while the whole garden was alive with other, equally worthy inquiries.
That afternoon, reading about the Apollo 11 guidance computer's Alarm 1201, I realized I'd been living this metaphor for fifteen years without knowing its name.
The Apollo Guidance Computer — built by Raytheon, programmed in assembly language, with roughly 74 kilobytes of read-only memory — was the brain of the Command/Service Module. During the powered descent to the lunar surface, it threw a repetitive Alarm 1201. The cause: the rendezvous radar, still attached even though it wasn't needed for landing, was flooding the computer with polling requests. The CPU was overloaded.
Here's what matters — and what I keep coming back to: the computer didn't crash. It adapted. Its executive software was designed to shed low-priority tasks and maintain the hard real-time deadline. It chose what to keep running and what to drop, repeatedly, for the entire descent.
But the computer didn't decide for itself. Its priority structure was determined by Margaret Hamilton and her team at MIT's Instrumentation Laboratory, months and years before launch. They had to ask the question: When everything demands attention, what actually matters?
My classroom of eighteen children, ages four through five, is also a real-time system with competing demands. The fire drill schedule overlaps with outdoor time. A child is having a big emotional moment. Three children are fascinated by a moth on the window screen. The curriculum says we should be learning about shadows today. The garden tomatoes need watering. The parent drop-off line is long because of road construction.
I am the executive. Every day, I shed tasks. Every day, I choose.
The Mission: Land on the Moon. The AGC's hard real-time deadline was maintaining the descent trajectory — everything else was shedtable.
The Classroom: The hard deadline is every child's sense of safety, curiosity, and agency. The curriculum is a schedule — and schedules, like rendezvous radar, are sometimes polling us unnecessarily.
This is where the connection becomes practical, not just poetic. I've started building this concept into our daily routines with the children themselves — not through lecture, but through the kind of embodied, hands-on experience that preschoolers learn from.
Each morning, after greeting circle, we do what I call "the priority scan." I hold up a simple diagram — a circle with three sections: Must (things we absolutely need to do), Could (things we might do if we have time), and Later (things we can come back to). The children help fill it in.
"Must: we need to wash our hands before snack. Must: Leo needs help with his zipper. Could: we could visit the worm hotel. Later: the shadow experiment — we'll do it when the sun's in the right spot."
It sounds simple. It is. But the children start internalizing something profound: not everything that asks for attention deserves it right now. That's not selfishness — it's systems thinking. It's the same logic that let two men walk on the Moon.
The other lesson from Apollo 11 is about trust. Neil Armstrong trusted that the guidance computer's designers had made the right choices about priority. But he also kept the manual controls in his hands — he could override the system if needed.
In my classroom, this translates to a question I ask the children regularly: "What would you do if the plan didn't work?" When we set up a block-building challenge and the tower keeps falling, or when the watering can leaks in the middle of garden time, the question isn't "start over" — it's "what's the most important part, and how do we protect that?"
Margaret Hamilton designed the AGC's executive software with a failsafe philosophy: if something unexpected happens, the system degrades gracefully rather than catastrophically. I try to build the same quality into my lesson plans. A good lesson plan has a core — a non-negotiable learning objective — and everything around it is optional scaffolding that can be shed if the children's attention goes elsewhere.
We're raising the first generation of children who will live their entire lives in a world of competing digital demands — notifications, alerts, pings, alarms. The Alarm 1201 story gives us a language for talking about attention management that is grounded in real engineering, real history, and real consequence.
When a five-year-old learns that even the computer that landed on the Moon had to choose what to pay attention to, they begin to understand something that many adults never do: that attention is a finite resource, and choosing what deserves it is an act of courage, not neglect.
The Apollo 11 source code has been reverse-engineered and published on GitHub by Chris Garry. You can actually read the assembly language that ran during powered descent — including the executive task scheduler that implemented the priority-shedding behavior. The alarm handling code is in the COMPUT.A11 file. It's not a bug fix; it's a deliberate design choice encoded in machine language fifty-seven years ago.
The technical analysis of the Alarm 1201 cause — rendezvous radar polling — comes from the MIT Instrumentation Laboratory's own post-mission debrief documents. Barbara LaFrance's analysis of the AGC as a quorum-consensus system helped frame this connection for me.
I'm sharing this because the connection felt too real not to put into words. If you teach young children, you know the weight of a thousand small demands. You know the guilt of watching one child's deep focus while three others need something. The Apollo 11 story gave me permission to reframe that tension: not as failure, but as real-time resource allocation — the same challenge that the smartest engineers of the twentieth century faced with the most consequential mission in human history.
We are not just teaching children about plants and numbers. We are teaching them how to decide, under pressure, what matters. That is not a small thing.
Grounded sources:
Apollo Guidance Computer: Wikidata Q138875 ·
Apollo 11 mission: NASA · Smithsonian Air & Space
Source code: github.com/chrislgarry/Apollo-11
Technical talk: 34C3: The Ultimate Apollo Guidance Computer Talk
Related work: ← Back to homepage