Apollo 8

"Earthrise"

GreenPolicy360: Those of our readers who are familiar with us may remember we have focused our work over decades on what we call The Modern Environmental Movement. Your founder/siterunner was there alongside a Congressman named George Brown, who put into development a first generation of Earth Science missions from space. These missions were foundational.

Earth Science Research from Space

https://www.greenpolicy360.net/w/Earth_Science_Research_from_Space

The Apollo-NASA missions to the moon changed the way humanity saw ourselves, as Apollo 8 sent home the first-ever full-color images of our living planet home. What some called a 'cognitive shift' occurred for many of us who were there as the image that became known as 'Earthrise' appeared in the media, most prominently on the cover of biggest magazine of the era.

“We came all this way to explore the Moon, and the most important thing is that we discovered the Earth." – Astronaut Bill Anders, Aboard Apollo, December 24, 1968

What your editor carried away was inspiration... and today I am remembering one of the quiet greats of the Apollo mission who made the flights and vision of planet Earth possible. Her name is Margaret Hamilton.

She literally wrote the source code that guided the missions to the moon, and her code (as I learned today) from the Apollo 8 'Earthrise' mission acted to make possible the correction of the Apollo 11 landing and return from the moon.

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August 17, 2026 - Happy 90th birthday to Margaret Hamilton -- the software engineer who wrote the computer code that saved the Apollo 11 moon landing and who, in the process, invented the discipline of software engineering itself! The system that kept that landing from being aborted began, improbably, with her 4-year-old daughter crashing a simulated moon mission.

Margaret Hamilton's daughter, Lauren, came along to the MIT lab on nights and weekends while her mother wrote the software that would fly astronauts to the moon. "There wasn't a time when we weren't working," Hamilton said. Lauren liked to play astronaut, because she had watched her mother do it in simulations. One evening she started hitting keys, and the simulation began to run. Then she hit another, and everything fell apart -- she had selected a program meant to be run before launch, and the computer, which had almost no memory to spare, wiped the navigation data that was taking her to the moon.

Hamilton saw what it meant immediately. "I thought: my God -- this could inadvertently happen in a real mission." She proposed a change to the software that would stop a prelaunch program from being selected in flight. Her superiors at MIT and NASA told her not to bother. The astronauts were too well trained to make a mistake like that.

On the very next mission, Apollo 8, an astronaut made exactly that mistake -- wiping the navigation data midway to the moon, just as Lauren had. Hamilton called it the Lauren bug. "It created much havoc and required the mission to be reconfigured," she said. "After that, they let me put the program change in, all right."

Hamilton was born in Paoli, Indiana, in 1936, earned a degree in mathematics with a minor in philosophy from Earlham College, and went to MIT in 1959 to support her family while her husband attended Harvard Law. She learned to program in the lab of Edward Lorenz, the meteorologist who would become the father of chaos theory, because there was nowhere else to learn it. "Computer science and software engineering were not yet disciplines," she said. "Instead, programmers learned on the job."

In 1964 her husband spotted a newspaper advertisement: the MIT Instrumentation Laboratory was looking for people to write the software to send a man to the moon. "I was attracted both by the sheer idea and the fact that it had never been done before," Hamilton said. "I was the first programmer to join and the first woman they hired."

She was gradually promoted until she was directing the team -- eventually about a hundred people -- that wrote the onboard flight software for both Apollo spacecraft. When she was given the job, one of the senior men told her he had no doubt she could do it but worried the men under her might rebel. "Well," she said, "they didn't."

Almost nobody thought the software mattered. It was not in the original schedule; it was not in the budget. "Software during the early days of this project was treated like a stepchild," Hamilton later wrote, "and it was regarded as an art and as magic, not a science." Out of what she called desperation, she started calling what she did software engineering -- a phrase invented to make a point.

"It was out of desperation I came up with the term, to say: 'Hey, we're engineering too.' It was an ongoing joke for a long time." The joke ended in a meeting, when one of the laboratory's most respected hardware men stood up and said she was right.

Then came July 20, 1969. Three minutes above the Sea of Tranquility, with two men aboard a vehicle that had never landed anywhere, the Apollo Guidance Computer began throwing alarms -- 1202, then 1201, five of them in four minutes -- because a rendezvous radar switch had been left in the wrong position and the machine was drowning in work it had no time to finish. On virtually any other computer of that decade, this was the end of the story: a freeze, a crash, a mission aborted.

Hamilton stood watching in the monitoring room at MIT while her software did what she had built it to do, which was to decide what mattered. It recognized the overload, discarded the low-priority jobs, restarted itself in a controlled and orderly way, and held onto the tasks that were flying the spacecraft. "It quickly became clear the software was not only informing everyone that there was a hardware-related problem," she said, "but was compensating for it."

In Houston a 26-year-old guidance officer named Steve Bales had a few seconds to call an abort, and because the computer was visibly managing itself, he called go. Neil Armstrong flew Eagle past a field of boulders and set it down with about twenty-five seconds of fuel remaining.

"If the computer hadn't recognized this problem and taken recovery action," Hamilton wrote two years afterward, "I doubt if Apollo 11 would have been the successful moon landing it was."

There is a famous photograph of her from that summer, standing beside a stack of Apollo source-code listings taller than she is. :"We got carried away and grabbed all the Apollo listings in my office and created the tower," she said. "I was trying to find a way of keeping the stack up."

Hamilton's standards held. In all the crewed Apollo missions that followed, no software bug was ever known to have occurred.

Hamilton went unrecognized for decades. In 2016 President Barack Obama gave her the Presidential Medal of Freedom, calling her emblematic of "that generation of unsung women who helped send humankind into space," and a year later she appeared, as a LEGO figurine.

Now ninety, Margaret Hamilton still argues that software should be designed at the start not to fail, rather than patched after it does ....

For young women who want to follow in her footsteps, she offers this advice: "Don't let fear get in the way, and don't be afraid to say 'I don't know' or 'I don't understand' -- no question is a dumb question. And don't always listen to the so-called experts." :To introduce this inspiring trailblazer to kids, consider the picture book "Margaret and the Moon" for ages 5 to 9 at https://www.amightygirl.com/margaret-and-the-moon) and the children's biography "Space Engineer and Scientist Margaret Hamilton" for ages 7 to 10 at https://www.amightygirl.com/margaret-hamilton

She is also featured in an activity book about pioneering women in technology, which includes a variety of hands-on STEM projects: "Gutsy Girls Go for Science: Programmers" for ages 8 to 11 at https://www.amightygirl.com/gutsy-girls-programmers

For adult readers who want the wider story of the women who put Americans in space, "Rise of the Rocket Girls: The Women Who Propelled Us, from Missiles to the Moon to Mars" tells of the mathematicians recruited by the Jet Propulsion Laboratory (JPL) in the 1940s and 50s at https://www.amightygirl.com/rise-of-the-rocket-girls

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June 7, 2024 ... In Memory of Astronaut William Anders

https://en.wikipedia.org/wiki/William_Anders

Associated Press / Former astronaut William Anders, who took iconic Earthrise photo, killed in Washington plane crash

https://apnews.com/article/plane-crash-san-juan-islands-washington-6d3800130ef4e67d761f96b328f7c263

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Apollo 8 Earthrise Photos

December 1968

• http://en.wikipedia.org/wiki/Earthrise

Apollo 8 photos in Life Magazine, January 1969

Earthrise

Apollo 8's View of Earth on December 24, 1968

December 21, 1968 ... Apollo 8 launches from the Kennedy Space Center, the first humans on the way to the Moon --- and a vision looking back at home that empowered the modern environmental movement.

Apollo's mission? To explore the Moon in preparation for a Moon landing. A surprise comes into view as the spaceship circles the Moon. A window view, Whole Earth awareness of ourselves as #PlanetCitizens. "Earthrise" ... a profound image, first by human hands taken of our home planet. We see our #PlanetEarth with new born eyes ...

The Earthrise photo history

100 Photographs That Changed the World

NASA simulation video of Earthrise on the 45th anniversary

• http://www.youtube.com/embed/dE-vOscpiNc

• http://www.abc.net.au/science/moon/earthrise.htm

• http://www.greenpolicy360.net/w/File:Apollo_8,_Life_Jan10,1969.png

Aboard Apollo, December 24, 1968...

http://www.greenpolicy360.net/w/Apollo_8

As the spaceship swings around the Moon...

Unexpectedly the Earth rises in the Apollo ship's window and the astronauts are amazed at what is coming into view... Astronaut Bill Anders is the first to see the Earth rising...

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Anders: "Oh, my God, look at that picture over there," he can be heard saying. "There's the Earth coming up. Wow, is that pretty!"

What happened next will sound familiar to anyone who remembers the days before digital cameras:

Anders (to astronaut Jim Lovell): "You got a color film, Jim? Hand me a roll of color, quick, would you?"

Lovell: "Oh, man, that's great! Where is it?"

Anders: "Hurry. Quick."

Lovell: "Down here?"

Anders: "Just grab me a color. A color exterior. Hurry up. Got one?"

Lovell: "Yeah, I'm lookin' for one. C368."

Anders: "Anything quick."

Lovell hands him the film just as Anders is heard saying, "I think we missed it."

But within seconds, Lovell sees the shot again in another window of the command module. He asks for the camera from Anders, who seems a bit defensive at having his role as mission photographer usurped.

Anders: "Wait a minute, just let me get the right setting here now, just calm down. Calm down, Lovell!"

Anders then gets the shot that has been reproduced innumerable times all over the world...

Changing forever humanity's vision of ourselves, of who we are

#PlanetCitizens