The entire source code for Apollo 11’s guidance computer was only 72 kilobytes

It’s hard to believe, but the entire source code for NASA’s Apollo 11 guidance computer was just 72 kilobytes. That’s smaller than most images or documents we send today! Yet, this compact codebase was enough to navigate astronauts over 238,000 miles to the moon and safely back to Earth.

The Apollo Guidance Computer (AGC) played a crucial role in the 1969 moon landing, performing complex calculations in real time to guide the spacecraft. Despite its limited memory and processing power—only 64KB of memory and a clock speed of 0.043 MHz—the AGC managed tasks that were mission-critical.

Today, the technology we carry in our pockets, like the iPhone, is exponentially more powerful, handling tasks with gigabytes of memory and speeds thousands of times faster. While our modern tech has grown immensely, the legacy of that tiny 72KB of code remains a testament to the ingenuity and precision that brought us to the moon.

This incredible achievement shows just how far technology has come, but also reminds us of the importance of creativity and human problem-solving, even with limited resources.