Video: 'APOLLO-SOYUZ: Crew Handshakes and Enters Soyuz - TV and Film from Apollo & Soyuz (1975/07/17)'

(Thursday, July 17, 1975, 3:19 p.m. EDT) — Astronauts of the United States and the Soviet Union united spaceships today and then Apollo commander Tom Stafford and Soyuz commander Alexei Leonov joined hands in the first international meeting away from earth, a symbolic gesture of the two nations’ expressed desire to cooperate in the exploration of space.

Video: 'Apollo-Soyuz Test Project Documentary' (3 videos)

The event essentially concluded the Space Race, a 20th-century competition between the Cold War rivals, the United States and the Soviet Union, to achieve superior spaceflight capability.

The Space Race had begun nearly 20 years before, on August 2, 1955, when the United States announced its intent to launch an artificial satellite, shortly after the Soviet Union had declared similar plans on July 29, 1955.