Seven astronauts were killed in the 1986 space shuttle Challenger disaster.

Forty years later, Cheryl McNair remembers the shock of watching the Challenger space shuttle fall to pieces with her husband, astronaut Ronald McNair, onboard.

“Having the first educator, Christa McAuliffe, on that flight, there was a lot of student interest because there were her lessons that she was going to do up in space that the kids could follow along ...