NASA lost seven of its own on the morning of Jan. 28, 1986, when a booster engine failed, causing the Shuttle Challenger to break apart just 73 seconds after launch. In this photo from Jan. 9, 1986, the Challenger crew takes a break during countdown train
NASA lost seven of its own on the morning of Jan. 28, 1986, when a booster engine failed, causing the Shuttle Challenger to break apart just 73 seconds after launch. In this photo from Jan. 9, 1986, the Challenger crew takes a break during countdown training at NASA's Kennedy Space Center. NASA

NASA lost seven of its own on the morning of Jan. 28, 1986, when a booster engine failed, causing the Shuttle Challenger to break apart just 73 seconds after launch.

In this photo from Jan. 9, 1986, the Challenger crew takes a break during countdown training at NASA's Kennedy Space Center. From left to right are Teacher-in-Space Christa McAuliffe and astronauts Gregory Jarvis, Judith Resnik, Mission Commander Dick Scobee, astronaut Ronald McNair, pilot Mike Smith, and astronaut Ellison Onizuka.