heart murmur a sound additional to the normal heart sounds, heard on auscultation of the heart. Many murmurs are of no significance (innocent, physiological murmurs), particularly in young children, or due to increased blood flow through the heart during exercise, or in pregnancy.
Columbia Space Shuttle Disaster. On February 1, 2003, the space shuttle Columbia was returning from its 28th mission when, 16 minutes to touchdown, the shuttle incinerated and broke apart over Texas. Communication between the Columbia crew and Mission Control captures the last moments of the flight.
The Space Shuttle Challenger Disaster occurred on January 28, 1986, when the NASA Space Shuttle Challenger broke up 73 seconds after liftoff. All seven crew members were killed. The cause of the explosion was a part called an O-ring that broke in the right solid rocket booster.