As determined by NASA, the needed skills included:
1. Long duration flight—a round trip to the moon would take more than a week
2. Extra Vehicular Activity (EVA)—astronauts would need to exit the spacecraft to walk on the moon
3. Rendezvous and docking—precision movement in space so that the command ship and lunar lander could join up and return to Earth
A few months after Alexi Leonov’s historic first space walk, astronaut Ed White performed America’s first EVA aboard Gemini 4.
Gemini 7 bettered that record with a 2 week flight. During that mission, Gemini 7 was joined by Gemini 6 which succeeded in performing a rendezvous with Gemini 7.