Just before noon on Jan. 28, 1986, the nation watched with eager anticipation as the space shuttle Challenger lifted off from Florida's Cape Canaveral.
Excitement and hope soon turned into horror just 73 seconds after liftoff when the space shuttle exploded, killing all astronauts on board.
One of its crewmembers was Christa McAuliffe, a teacher from New Hampshire who won a national competition to become the first teacher in space.
The goal was to boost interest in space exploration among American school children.
"The teachers took us all outside and we were all standing around, and we watched as the smoke plume went up in the sky and then it did that...like, "V," you know, and the teachers immediately just, like, swarmed everybody back into the classrooms," recalled witness Kari Anna Roy.
The horrifying image of that massive fireball in the sky was replayed endlessly on television and burned into Americans' memories.
President Ronald Reagan was scheduled to deliver his State of the Union address that night. Instead, Reagan tried to comfort a grieving nation.
In 2004, President George W. Bush announced the retirement of the aging shuttle fleet. Just three more launches remain. Astronaut Mark Kelly, the husband of Rep. Gabrielle Giffords who was injured in the Jan. 8 shooting in Arizona, is scheduled to command the second of those three missions.
The Challenger's commander was instrumental in establishing the Challenger Center for Space Science Education.
There are nearly 50 Challenger learning centers worldwide where thousands of school children are taught to reach for the stars.