World Cosmonautics Day - 50th Anniversary

Today is the 50th anniversary of World Cosmonautics Day which celebrates the first manned spaceflight made by Yuri Gagarin.    The flight of Vostok 1 from the Baikonur Cosmodrome  launched (no pun intended) the era of space exploration.   The etymology of  launch is interesting:  it is derived from the Latin lancea  (lance in English).  Lance  has several related meanings. As a noun it is a spear-like weapon of war and also a surgical instrument.  Verbially, it means to pierce (to make an opening in).  


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Vostok 1 achieved an orbital trajectory.  This meant that the spacecraft needed a "retro burn" to slow it down enough to change the flight path to one that entered the atmosphere,  and could slow down  further by air drag,  and eventual landing on earth via parachute.   If the retro-rockets had failed,  Yuri would have been in orbit for a long time.  A few weeks later,   the USA launched the spacecraft  Mercury-Redstone 3.  The American mission was a sub-orbital  space flight.   Retro-rockets were required on the mission to achieve a "splashdown"  300 miles downrange from the launch site.   Although the first manned American effort was much less bold in scope,  it heralded the rapid surpassing of the Russians in space technology and boldness which led to the successful lunar landing missions beginning with Apollo 11.

This classic photograph of the Earth was taken on December 7, 1972. The original caption is reprinted below: View of the Earth as seen by the Apollo 17 crew traveling toward the moon. This translunar coast photograph extends from the Mediterranean Sea area to the Antarctica south polar ice cap. This is the first time the Apollo trajectory made it possible to photograph the south polar ice cap. Note the heavy cloud cover in the Southern Hemisphere. Almost the entire coastline of Africa is clearly visible. The Arabian Peninsula can be seen at the northeastern edge of Africa. The large island off the coast of Africa is theMalagasy Republic. The Asian mainland is on the horizon toward the northeast.

http://visibleearth.nasa.gov/

Enjoy.