(It would not be the last.) I suppose I could have waited until the 40th anniversary next year to write this reminiscence, as my editor suggested this morning, but, then again, you never know when ...

Corrections & Clarifications: An earlier version of this story misstated the date of the Space Shuttle Columbia disaster ... the nation marks the 39th anniversary of the explosion that destroyed ...

Tuesday marks the 39th anniversary of the Space Shuttle Challenger ... McAuliffe was one of the seven crew members killed in the disaster. Crew members Dick Scobee, Mike Smith, Ronald McNair ...