In this task, you are given a question and a context passage. You have to answer the question based on the given passage.

How many people were there at the docking?, Context: 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.
three astronauts conducted joint experiments with the two cosmonauts