Do you remember where you were on this date 27 years ago (1986)? What were you doing when you heard that the space shuttle Challenger had exploded? What were your feelings at that time?

At 10:38 am CST, I was driving from a college class to the dentist’s office where my mother worked. As usual, I had the radio on, listening with pleasure to the news of the shuttle’s lift-off. It had been scheduled for January 23, but weather and technical problems delayed it until the 28th when finally, in spite of the cold, the decision was made to go ahead with the launch.

The whole country was excited about Christa McAuliffe, a 37-year-old high school teacher who would be the first U.S. civilian in space. We had heard about her training, her background, and her personality. Since she was not a professional astronaut, the rest of us — ordinary civilians who would probably never go into space — felt a kinship with her, as if she were a symbol we could all relate to.

As I listened to the countdown on the radio, I felt a flush of excitement run through me. I imagined myself in the shuttle, trying to prepare for the pressure of acceleration and the disorientation of free fall. I heard the cheers as the shuttle blasted off.

Less that 2 minutes later, the cheers turned to sobs and gasps of horror. I couldn’t believe what I was hearing. I quickly reached the office to tell my mom, but they already had it on the waiting room TV. I sat for a long time and watched CNN’s coverage, just trying to take it in.

A special investigative commission, appointed by then-President Reagan, determined that the tragedy occurred due to the failure of an ‘O’-ring seal on one of the solid-fuel boosters. The failure was most likely due to the cold weather, since cold temperatures reduce the pliability of the rubber and allow fuel to leak. In fact, npr reported,

… engineer and several others were not surprised when Challenger exploded 73 seconds after liftoff on Jan. 28, 1986. They worked for Morton Thiokol (now ATK Thiokol), the Utah-based NASA contractor which produced the solid rocket motors that lifted space shuttles from their launch pads….

…Some of those Thiokol engineers expected o-ring failures at liftoff. They knew that cold overnight temperatures forecast before launch would stiffen the rubber o-rings. They knew that stiff o-rings didn’t provide a secure seal. In fact, there had been evidence of leakage, what the engineers called “blowby,” on an earlier shuttle flight. This would be the coldest launch ever.

Although failure of the ‘O’-ring, with a resultant leak, was considered to be the direct cause of the explosion, there were also indirect causes, such as lack of communication, failure to adhere to recognized safety standards, and “groupthink” — defined by RationalWiki as “Groupthink occurs when individuals in a group fail to express their doubts about the group’s dynamic, direction or decisions because of a desire to maintain consensus or conformity.” Groupthink often results in denial of reality and negative consequences.

Here is an archived video from NASA that gives a close-up of the explosion (click the picture):

Last spring, this home video footage of the disaster was uncovered. It is especially poignant because in the background you can hear words of shock and grief. Click the picture to watch the video.