Rest in peace, Challenger crew. On this date in 1986, the Space Shuttle Challenger STS-51-L mission exploded 73 seconds after takeoff, killing all seven members of the crew [Commander Dick Scobee, Pilot Michael Smith, Mission Specialist Ellison Onizuka, Mission Specialist Judith Resnick, Mission Specialist Ronald McNair, Payload Specialist Gregory Jarvis, and Payload Specialist/Teacher in Space Christa McAuliffe]. Their mission was, among other things, to monitor Halley’s Comet, the deployment of a satellite, two lessons for the Teacher in Space Program, and Gregory Jarvis was planning to play the saxophone for Jean-Michel Jarre’s album Rendez-Vous. It’s been 50 years (almost to the day) since we lost Apollo 1, and it’s hard to believe it’s been 31 since we lost Challenger--but that means it’s only 44 years until Halley comes ‘round again. We’ll be thinking of you and wishing you, as always, Godspeed, our valiant crews.