The space shuttle Challenger STS-51L spaceflight ended in tragedy on Jan. 28, 1986, 73 seconds after liftoff. Seven astronauts died that day, when the Challenger space shuttle was destroyed.
It was NASA's first in-flight calamity, and it dealt an especially severe blow to the millions of teachers and students watching on TV to see Christa McAuliffe, a civilian high school teacher from New Hampshire, become NASA's first Teacher in Space.
Today is the 25 year anniversary of that fateful day.
The loss of Challenger was later attributed to a failed seal on one of the space shuttle's solid rocket boosters. An investigation board concluded that cold weather prevented a rubber O-ring from maintaining its seal, allowing hot gas to leak and damage the shuttle's external fuel tank and the hardware attaching the booster to the vehicle. The right solid rocket booster separated from the shuttle, and the fuel tank broke apart, causing the orbiter to be torn apart by aerodynamic stresses.
"The problem was a design flaw, complicated by the weather situation which was unrecognized at the time by the appropriate managers," Hale said. "We wished that we had the foresight to stand up collectively and say, 'Look, it's too cold a day to launch, we just ought to wait for a warmer day.' In retrospect it seems so simple; at the time, it just didn't happen."
Veteran shuttle astronaut Ron Garan, who is slated to fly to the International Space Station in March aboard a Russian Soyuz spacecraft, said the anniversaries of Challenger and the other accidents highlight the lessons learned from those events. "It's a time to reflect and it's a time to remember those people who have sacrificed to get us where we are," Garan told SPACE.com. "A lot of the lessons learned in this business are written in blood, and if we don't learn from them, those people died in vain."
So where were you on that day? Were you watching from a classroom like many students?