My career as an astronaut—from the wild ride of training to the challenges and drama of missions—began in the Infinite Corridor.

Not everyone can point to the specific moment that set them on their life’s course. But for me, there’s no question: It happened in 1982, when I was a junior at MIT, in the Infinite Corridor. In those pre-internet days, it was where we got the scoop about everything that was happening on campus. One day, as I was racing to the chemistry labs, a poster caught my eye.

As I remember it, the poster showed a smiling woman in a flight suit, holding a helmet by her side. I recognized her immediately: Sally Ride, one of America’s first group of female astronauts. It had just been announced that she would be part of the crew for one of the upcoming space shuttle flights, making her the first American woman in space. And while she was visiting Lincoln Lab for training, she would be giving a speech and attending a reception hosted by the Association of MIT Alumnae. A woman speaker was still a novelty at MIT in those days. But a woman astronaut? I knew this was one event I had to attend.

On the day of Sally Ride’s talk, I hurried into 10-250, the large lecture hall beneath the Great Dome that is the emblem of MIT. Sandy Yulke, the chair of the Association of MIT Alumnae, was already introducing Sally. Sally. Just a first name. As if she were one of us. I slid into an empty seat just a few rows back as Sandy talked about how proud she was to welcome the soon-to-be first American woman in space. And Sally was standing there, right where our professors stood every day. A woman. And an astronaut.