Project Gemini
In doing so , it allowed the United States to catch up and overcome the lead in human spaceflight capability the Soviet Union had obtained in the early years of the Space Race , by demonstrating: mission endurance up to just under fourteen days , longer than the eight days required for a round trip to the Moon; methods of performing extra-vehicular activity ( EVA ) without tiring; and the orbital maneuvers necessary to achieve rendezvous and docking with another spacecraft . 
<triplet> Space Race <subj> Soviet Union <obj> participant