Space docking

Gemini VIII achieved the first docking of two space vessels in orbit, demonstrating a crucial capability for future lunar missions. This milestone was essential for planning manned Moon landings and returns.
 (NASA) United States 1966 Space docking

Gemini VIII achieved the first docking of two space vessels in orbit, demonstrating a crucial capability for future lunar missions. This milestone was essential for planning manned Moon landings and returns.