1955 in spaceflight

In 1955, both the United States and the Soviet Union (USSR) announced plans for launching the world's first satellites during the International Geophysical Year (IGY) of 1957–58. Project Vanguard, proposed by the US Navy, won out over the US Army's Project Orbiter as the satellite and rocket design to be flown in the IGY. Development of Intercontinental Ballistic Missiles, the Atlas by the US and the R-7 by the USSR, accelerated, entering the design and construction phase.

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