Twenty-five years later, the images are no less horrifying. People around the world watched as seven astronauts met their death in the explosion of the space shuttle Challenger on Jan. 28, 1986.
Those who remember that freezing cold morning will have no doubt vivid recollection of the disaster. School children, in particular, had an interest in the launch, as New Hampshire schoolteacher Christa McAuliffe was part of the crew. McAuliffe was scheduled to become the "first teacher in space" through the NASA Teacher in Space educational project, and many schools broadcasted the launch on live television.
The shuttle exploded due to a faulty O-ring in one of its rocket boosters that allowed hot gases to burn a hole in the fuel tank. The frigid weather had caused the O-ring to shrink. The resulting explosion was so shocking that television announcers covering the launch seemed unable to comprehend what they had seen.
The worst part of the disaster was the eventual conclusion that it could have been prevented. Partial failures and warnings about the O-rings had been dismissed by NASA managers prior to the launch. That same failure to act led to a similar explosion of the Columbia shuttle - and the death of seven more astronauts - 17 years later.
Safety practices at NASA are now painstakingly stringent, to the point where the next launch has been delayed since early November due to extensive testing. The improved practices won't bring back those who have been lost, but will clear the way for those who dare to discover for generations to come.
Space exploration has its benefits, most importantly as a cause to continue challenging ourselves as people. Those of us who remember Challenger know that this comes at a high cost but can take comfort in knowing our horizons continue to grow.