Armstrong and Aldrin unfurl the US flag on the moon, 1969.

Armstrong and Aldrin unfurl the US flag on the moon, 1969. Apollo 11, the first manned lunar landing mission, was launched on 16 July 1969 and Neil Armstrong and Edwin Aldrin became the first and second men to walk on the moon on 20 July 1969. The third member of the crew, Michael Collins, remained in lunar orbit. (Photo by Oxford Science Archive/Print Collector/Getty Images)