Sputnik was the first unmanned satellite launched into orbit in 1957. During which decade were manned satellites first sent into orbit?

Sputnik was an unmanned satellite launched in 1957. The first human to orbit Earth was Yuri Gagarin in 1961 aboard Vostok 1, so the first manned spacecraft entered orbit during the 1960s. The correct choice is A, 1960s.

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