Margaret Hamilton: the woman who sent humans to the moon

Rosalind Franklin solved the structure of DNA, Marie Curie pioneered research on radioactivity, and Lise Meitner was a key player in the discovery of nuclear fission. If like me, you were a STEMinite and took science A-levels, you were exposed to the groundbreaking accomplishments these women made – and when you consider the extent of social biases at the time, you realise these pioneers acted as so much more than scientists: they  broke a chain of social norms that defined their role in science as nothing but invasive.  

Praise readily falls on these women nowadays and many hail them as the perfect role models, not restricted to young women seeking to make a career in STEM. However, not all women in science were lucky. Countless stories are told of breakthroughs overseen because of gender – even Dr Franklin, the most famous female biologist to date, was robbed of a Nobel Prize with Crick and Watson.  

One particularly disregarded story is that of Margaret Hamilton, a software engineering frontrunner that enabled the infamous landing of Apollo 11 on July 20, 1969. 

There was a hardware problem; the rendezvous radar was wrong, and they were desperately running out of fuel

Everything was working perfectly. Neil Armstrong, Michael Collins and Edwin “Buzz” Aldrin were circulating over 200,000 miles away from the earth in the Eagle – Apollo 11’s lunar module – and could nearly taste the cheese of the moon’s surface. Potential first comments were being shared and hope filled the air as the three men set themselves on a path to be eternally remembered. However, just as complacency began to diffuse through the air, critical computer messages took over their periphery, followed by deafening sirens obscuring any possibility of verbal communication between the trio. The onboard computer software was telling the crew that there was a hardware problem; the rendezvous radar was wrong, and they were desperately running out of fuel.  

Margaret Hamilton, born in 1936 in Indiana, was a maths lover from an early age. Following her departure from college, she took a job at the Massachusettes Institute of Technology (MIT), working as a software developer for a weather prediction device. A year later, she began programming systems to locate enemy planes in the Semi-Automatic Ground Environment (SAGE) program. In the 1960s, in lieu of the alleged Soviet’s heightened efforts to reach the moon, MIT announced they wanted programmers to help with the lunar US mission, and Margaret Hamilton, later in an interview said she thought ‘Wow, I’ve got to go there’. Instead of attending graduate school at Brandeis University, where she would have studied abstract mathematics, she moved to the U.S. space program to become head of the MIT instrumentation laboratory – a team dedicated to developing software for Apollo 11’s two computers – and was the first programmer hired for any Apollo project.  

When asked about her decision to pursue this mission rather than a doctorate, she said “there was no choice but to be pioneers”. A bold mentality for a woman to have in an industry that tried their best to label her as an outsider. 

She [Margaret Hamilton] viewed all missions as a system, stating “part is realized as software, part is peopleware and part is hardware”

Margaret Hamilton had built a software – with a computer containing a million times less processing power than our current mobile phones – to recognise error messages and ignore low priority tasks, thus making other softwares more reliable and less prone to shutting down due to unimportant malfunctions. A concise summary of her work ethic and method of thinking comes from an anecdote of her bringing her daughter to work whenever she had extra morning and night shifts. One day her daughter pressed a simulator button that caused a whole system shut down. Margaret, obviously, therefore wanted to install protection like this on the aircraft, but was told that astronauts ‘are trained not to make mistakes’ – which was interesting advice, considering Jim Lovell did the exact same thing on Apollo 8’s failed mission – all for listening to the scientists. This piece of thinking, I believe, clearly displays Margaret’s way of thinking, she viewed all missions as a system, stating “part is realized as software, part is peopleware and part is hardware”. 

With all systems blazing with errors both on board the vessel and back on earth, mission control faced a “go/no-go” decision, with Margaret Hamilton at the forefront of the astronauts’ fate. With little hesitation, Margaret told the crew to ignore the messages and proceed with the mission as planned. She trusted that everything wouldn’t shut down and that her system would allow a safe and comfortable landing. With tense anticipation, mission control received a message from Neil Armstrong claiming ‘The Eagle has landed’ – with 30 seconds of fuel left, because of an error on the astronauts’ checklist, telling them to set the rendezvous radar switch incorrectly. 

The innovative work of Margaret Hamilton is hailed by many, including Air and Space Museum curator Teasel Muir-Harmony who recently, in an interview with the Smithsonian magazine, praised Margaret for being “really expansive as a programmer, coming up with solutions for problems, very innovative, very outside-the-box thinking”.  Yet very few, outside of astrophysics, know her name. Those who landed on the moon are greatly recognised worldwide, yet the crux of their achievement was entirely in the hands of those who developed the software that got them there in the first place.  

 “My God. Look what happened. We did it. It worked.”  – Margaret Hamilton

It’s interesting. So much was on the line for the three men. A wrong call and the chances of a return were close to impossible. You’d think in this situation you’d be exceedingly cautious, you’d think of lives, of reputation, of peopleware over hardware. Margaret thought differently. She backed her creation, and in some way, gambled with life. Was this reckless? Was it adrenaline taking over rational thought, replacing logic with a fervent desire for completion? I guess we don’t know. Maybe this stress encourages concentration, maybe she did think of the rationale. Maybe if you zone in deep enough these thoughts don’t pass your head and you take refuge in your strongest instincts, bypassing all methods of conscious thought. But even Margaret Hamilton seemed taken aback when she concluded the mission. Whether this reflects surprise at the result, or her own ingenuity, she said: 

 “My God. Look what happened. We did it. It worked.”