Believing with their hearts that practice makes perfect, and willing to spend a few hundred million dollars to prove it, NASA's spaceflight team invented Project Gemini as a bridge between Mercury and Apollo. Ten manned missions were flown during the two-year period of 1965 to 1966, including the first (Gemini 4) that was controlled from Houston.

By the time Gemini was flying the space agency had pretty much decided how it was going to get to the Moon, and it knew that astronauts and flight controllers alike had to learn how to rendezvous and dock two spaceships together. To practice during the two-man Gemini flights meant launching something for the team to go chase.

The target of choice was a specially equipped Agena upper stage that was launched into Earth orbit by an Atlas booster. Sometimes the Atlas worked, and sometimes it didn't -- forcing Mission Control to scramble to come up with a new plan. Gemini 6 lost its Agena and wound up rendezvousing with Gemini 7. Gemini 8's Agena made into orbit. Gemini 9's didn't.

To salvage the Gemini 9 mission, a back-up plan was put in work in which a spaceship known as the Augmented Target Docking Adapter was lofted into orbit by an Atlas. But when the manned Gemini 9 capsule arrived on the scene they discovered that the nose cone was partially in place and blocking the docking collar.

Tom Stafford and Gene Cernan, looking out their window at the unusual sight, quickly dubbed the ATDA as an "angry alligator" and once again Mission Control was forced to work overtime to save the flight. Not all of the goals of the mission could be accomplished, but NASA was able to make the remaining days of Gemini 9 productive and put the nation one step closer to the Moon by the end of the decade.