Today In History: Apollo-Soyuz Mission

On July 15, 1975, three American astronauts blasted off aboard an Apollo spaceship for a historic mission that included a linkup with a Soviet spacecraft. On the same day, two Soviet cosmonauts were launched aboard a Soyuz spacecraft.

The Apollo and Soyuz spaceships linked up 140 miles above the Earth two days later. The two ships were joined for two days, during which the astronauts shuttled back and forth between cabins through a connecting tunnel. They shared meals, experiments, and conversation, and traded flags and other souvenirs.