A b c or d is that in this question
The Space Race began on August 2, 1955, when the Soviet Union responded to the US announcement four days earlier of intent to launch artificial satellites for the International Geophysical Year, by declaring they would also launch a satellite "in the near future". The Soviet Union beat the US to this, with the October 4, 1957 orbiting of Sputnik 1, and later beat the US to the first human in space, Yuri Gagarin, on April 12, 1961. The race peaked with the July 20, 1969 US landing of the first humans on the Moon with Apollo 11. The USSR tried but failed manned lunar missions, and eventually cancelled them and concentrated on Earth orbital space stations
