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In 1962, an astronaut about to be blasted into orbit looked at NASA's brand-new, room-sized computer and said: nope, have Katherine check it. Katherine was Katherine Johnson, a mathematician with a pencil, a desk calculator, and a reputation for never being wrong. He would not fly until she said the numbers were good.
The Deep Dive
Katherine Johnson grew up in West Virginia counting everything: steps to the road, dishes in the sink, stars she could see. She started high school at 10 and finished college at 18. When she joined the agency that became NASA, her job title was "computer." Back then, a computer was a person who did math all day, not a machine that crashes during your homework.
Her specialty was figuring out the path a spacecraft would take, called a trajectory. John Glenn's capsule would circle Earth at about 17,500 miles per hour, fast enough to cross the entire United States in under 10 minutes.
Here's that math worked out: 17,500 miles in 60 minutes means 17,500 ÷ 60, or about 292 miles every single minute. Get one number wrong at that speed and the capsule comes down hundreds of miles from the rescue ships. NASA had new electronic computers to do the work, but they were known to glitch. So Katherine spent about a day and a half redoing every calculation by hand.
Her numbers matched the machine's. A man about to sit on top of a rocket trusted one person's pencil more than a computer the size of a room. Think about how sure of your math you'd have to be for someone to bet their life on it.
She did all this while facing unfair rules. Katherine was a Black woman at a time when Black employees had to use separate offices and bathrooms, and women were kept out of important meetings. She asked to be let in until they let her in. Seven years later, her math helped Apollo 11's lander meet back up with its mother ship above the Moon, like tossing a sock to a friend zooming past on a bike at thousands of miles per hour.
You've done a tiny version of her job. Every time you throw a ball to someone and aim a little ahead of where they're running, your brain is predicting a trajectory. Katherine did it with numbers, for a target 240,000 miles away.
Hands-on Activity
Be the Human Computer
You need: a pair of rolled-up socks, paper, a pencil, and something to mark the floor (a spoon works).
Stand in one spot. This is your launch pad.
Before you throw, place the spoon where you think the sock will land. That's your prediction.
Toss the sock underhand, gently. Watch the shape it makes in the air.
Sketch that shape on your paper. It should look like a rainbow or a hill. That curve is a trajectory.
Measure how far off your spoon was, in footsteps. Write it down.
Throw five more times with the same strength, moving the spoon each time. Watch your misses shrink.
Now change one thing: throw harder, or aim higher. Predict first, then throw. How did the arc change?
By throw six, you're doing what Katherine did: using what you know about the path to predict the landing..