
I know that the answer to the question "How many American were docked?" is in "The joint mission began when Soyuz 19 was first launched on July 15, 1975 at 12:20 UTC, and the Apollo craft was launched with the docking module six and a half hours later. The two craft rendezvoused and docked on July 17 at 16:19 UTC. The three astronauts conducted joint experiments with the two cosmonauts, and the crew shook hands, exchanged gifts, and visited each other's craft.". Can you tell me what it is? 


three
