CAPE CANAVERAL, FLORIDA: Moments after the space shuttle Challenger lifted off from the Kennedy Space Center on January 28, 1986, millions of people watching a textbook launch around the world saw it explode in a horrific fireball, killing seven astronauts, including school teacher Christa McAullife. TIME's Jerry Hannifin reports: "NASA learned a hard lesson with this tragedy. It learned not to be so damn complacent about machinery and the people who monitor that machinery. It changed the mindset of NASA, which up to that time had a sense of overweening self-confidence. That arrogance contributed to the explosion. NASA lost not only the public confidence, but some of its own self-confindence as well. The lessons they were forced to learn might prevent this kind of tragedy from happening again."