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.
Just before noon on January 28, 1986, people watched with excitement as the space shuttle Challenger lifted off from its Florida launch pad -- but that excitement and hope soon turned into horror. Just seventy-three seconds after liftoff, Challenger exploded, killing all seven astronauts on board. One of its crew members was Christa McAuliffe, a school teacher from New Hampshire who had won a national competition to become the first teacher in space.