A
laser is an optical device that emits
light (
electromagnetic radiation) through a process called
stimulated emission. The term "laser" is an
acronym for
Light Amplification by Stimulated Emission of Radiation.
[1][2] Laser light is usually spatially
coherent, which means that the light is either emitted in a narrow, low-
divergence beam, or can be converted into one with the help of optical components such as
lenses. Typically, lasers are thought of as emitting light with a narrow
wavelength spectrum ("monochromatic" light). This is not true of all lasers, however: some emit light with a broad spectrum, while others emit light at multiple distinct wavelengths simultaneously. The coherence of typical laser emission is distinctive. Most other light sources emit
incoherent light, which has a
phase that varies randomly with time and position.
Christopher Columbus Kraft, Jr. (born
February 28,
1924) is a retired
NASA engineer and manager. After graduating from
Virginia Tech University in 1944, Kraft was hired by the
National Advisory Committee for Aeronautics (NACA), the predecessor organization to the
National Aeronautics and Space Administration (NASA). He worked for over a decade in aeronautical research before being asked in 1958 to join the
Space Task Group, a small team entrusted with the responsibility of putting America's first man in space. Assigned to the flight operations division, Kraft became NASA's first
flight director. He was on duty during such historic missions as America's
first spaceflight,
first orbital flight and
first spacewalk.
At the beginning of the Apollo program Kraft retired as a flight director in order to concentrate on management and mission planning. In 1972 he became director of the Manned Spacecraft Center (later Johnson Space Center), following in the footsteps of his mentor Robert Gilruth. He held the position until his retirement from NASA in 1982. During his retirement, Kraft has consulted for numerous companies including IBM and Rockwell International, and he published an autobiography entitled Flight: My Life in Mission Control.
