[♪ INTRO] On paper, NASA has surprisingly few  job requirements for its astronauts.

An astronaut needs a master’s degree in a STEM  field and two years of related experience, and they need to pass a  pretty rigorous physical test. And that’s it.

But these are astronauts. They tend to go above and beyond. So here are a few things that aren’t on that list: Having a doctorate in engineering, co-inventing technology that people will  still use almost thirty years later, teaching computers to think with  light instead of electricity, being good enough to be a classical flautist, and being cool enough to play a flute in space.

That was the resume of just one  applicant in 1990: Ellen Ochoa. Who is awesome, in case you haven’t realized it. Ellen Ochoa grew up in southern California, and considered going to school for music  until she caught the bug for physics.

She became an electrical  engineer and studied optics, or the way that light interacts with materials. Some of her research focused on how to make  basic parts of a computer work with light instead of electricity, which is something  engineers are still working on today. The thinking is that light   doesn’t interfere with itself as much  as electrical signals do, so you can cram more different messages into the same  space with light than you can with electricity.

But mostly, Ochoa wasn’t trying  to build computers with light. She was trying to understand pictures with light. Which might sound… weird.

I mean, a picture is made up of light. Like, if there’s no light,  there’s nothing for you to see. So, how else would you understand it?

But how your eyes see an image isn’t  the same as how it looks to a computer. To a computer, an image is a big grid of numbers: a certain amount of light from this pixel,   a certain amount of light  from that pixel, and so on. To a computer, an image isn’t all  that different from a spreadsheet.

And to a computer, looking for patterns in  that picture means comparing every single pixel to the pixels around it, and to the  pixels around the pixels around it. That is a nightmare, especially  for the computers of 1985. So Ochoa was looking at what’s  called optical image processing, which uses the actual light from an  image, not the spreadsheet of pixels.

The light is put through  filters that can do things   like increase the contrast or highlight the edges. She and her colleagues invented a way to  scan the templates that get used to make computer chips for defects, so that those  defects don’t make it into the chips themselves. Today, this technique gets used a lot in medicine.

Computers can have a hard time finding  the edges of something like a cell, which can look a lot like its surroundings. But with the right filters, cells,  organs, and tissues can all pop right out. The newly minted Doctor Ellen Ochoa  was not interested in biology, though.

Her sights were fixed a couple hundred  kilometers above the rest of us. So in 1987, she applied to be an astronaut. …And she was rejected. Along with a thousand other applicants.

But Ochoa isn’t one to give up. She got her pilot’s license to make herself  a stronger candidate for the next round, and she kept studying images,  now as a professional engineer. Ochoa invented ways for computers  to check multiple pictures and realize that they are all of the same object.

Armed with that fact, the computer  could stitch together a clearer visual of the object than any one  picture revealed on its own. And that is exactly what you’d  want if you’re, say, a space agency with a million pictures of Saturn’s moons, and you want to know if blips in the pictures  are interesting craters or boring static. Or if your robot is about to land on Mars  and it needs to figure out on its own whether it’s about to land on a single  giant rock or a bunch of small ones.

And so, after NASA rejected another  astronaut application from her in 1987, Doctor Ochoa went to work for NASA as an engineer. By 1990, she’d published over a dozen papers  about optics and image processing, co-filed three patents, and was at the head of a team  of thirty-five other scientists and engineers. And despite two attempts, she  had still never been to space.

But that was about to change. NASA finally accepted her application, and on  April 8, 1993, at just after 1:30 in the morning, Ellen Ochoa became the first  Hispanic woman in space. While she was up there, Ochoa and her  crewmates conducted a bunch of experiments to understand how solar activity  affects Earth’s weather and climate.

And they also radioed in to schools around the  world to talk about what life is like in orbit. Almost twenty years after she  chose physics over fluting, it was only fitting that Ellen Ochoa was part  of yet another first on that shuttle mission: She was the first person to  ever play the flute in space! Ochoa went back to space three more times  and did all the awesome stuff astronauts do: She brought supplies to the International  Space Station while it was being built, she studied the Sun more, she  spacewalked for eight hours, she used the station’s robotic arm to drag  satellites and astronauts around in space.

Then, with both feet firmly back on the  ground, Doctor Ochoa became deputy director of Johnson Space Center, and  later its first Hispanic director. Where she was finally the one in  charge of choosing astronauts. Today, Ellen Ochoa continues speaking  to audiences around the world.

But her name might sound a bit  familiar to you for another reason. Schools all around the United States  are named after this incredible woman. And if you went to one of those schools,  you’re part of that legacy, too.

Thanks for watching this episode of SciShow, and thanks as always to the amazing  community of patrons who make it possible. If you would like to get involved, you  can head over to patreon.com/scishowspace. [♪ OUTRO]