On March 16, 1966, the crewed Gemini 8 spacecraft became the first to dock with another spacecraft in space.

NASA astronauts Neil Armstrong and David Scott launched into orbit in their Gemini spacecraft almost three hours after the uncrewed Agena target vehicle launched separately. After a six-hour chase, the Gemini crew caught up with the Agena target vehicle, and the two spacecraft successfully docked. Then the problems started. The joined spacecraft started to tumble out of control. Assuming the problem had to do with the Agena target vehicle, they decided to undock. But shedding the extra weight actually made the Gemini spacecraft spin even faster, and it was rotating at one revolution per second. This made the astronauts pretty dizzy, but they still managed to safely execute an emergency landing.