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 is lost just after liftoff on this day in 1986, killing the seven astronauts aboard. The Challenger was the second shuttle built by the National Aeronautics and Space Administration (NASA). It took its first flight into space on April 4, 1983, and made a total of nine...