Agena docking target vehicle as seen from Gemini 8 before the mission’s historic docking on March 16, 1966. (Image credit: NASA) Meeting with history ...

A radio-controlled “Agena target vehicle” would be put in orbit first; then Gemini 8 would launch, catch up to the Agena, and gently slide its nose into a docking collar on the Agena’s nose.

Gemini 8’s ordeal began shortly after its docking triumph, when Armstrong and Scott began a program of planned maneuvers to test the stability of the Gemini-Agena system.

Soon after that, Gemini 11 in September 1966 achieved an Agena-D docking on its first orbit, 85 minutes after launch, simulating an emergency rendezvous between an Apollo LM and CSM.

NASA . The Gemini 10 astronauts successfully docked their spacecraft with the Agena Target Docking Vehicle and boosted the combined crafts into a higher orbit with an apogee of 413 nautical miles ...

Gemini VIII’s Agena during the fly-around shortly before docking. Twenty-seven minutes later, as the Agena was executing a planned maneuver to turn the combined spacecraft 90 degrees, Scott ...

Soon after that, Gemini 11 in September 1966 achieved an Agena-D docking on its first orbit, 85 minutes after launch, simulating an emergency rendezvous between an Apollo LM and CSM.

It began as one of those flawless launches that the U.S. public has come to take for granted in the eighth year of the space age. Weather was ideal; the complex countdown proceeded without a hitch.