The Space Shuttle Challenger Disaster: In January 1986, the Space Shuttle Challenger broke apart 73 seconds after liftoff, killing all seven crew members aboard. The incident was significant because it was the first time a civilian was flying on the shuttle. Teacher Christa McAuliffe was supposed to be the first teacher in space, creating video lessons for students around the world. The disaster was blamed on the failure of the O-rings due to the cold temperatures.
The Space Shuttle Columbia Disaster: In February 2003, the Space Shuttle Columbia broke apart during its reentry into Earth's atmosphere. All seven crew members died. In this case, the disaster was a result of damage sustained by the shuttle's thermal protection system after a hole was punched in the shuttle's wing when it was hit by a piece of debris during liftoff. This caused the wing to absorb too much heat and eventually break apart.Learn more about Space Travel