Christa McAuliffe's lesson that waited 32 years

Thirty-two years later, her unfinished lessons finally reached orbit.

NASA selected the high-school history teacher for the Teacher in Space Project in 1985. She planned two live lessons and six filmed demonstrations, but Christa and her six crewmates were killed when Challenger broke apart shortly after launch.

Her lesson plans survived. In 2017–18, astronauts and former teachers Joe Acaba and Ricky Arnold performed several of her planned demonstrations aboard the International Space Station—allowing another generation to receive the lesson.