Which astronaut experienced complete isolation from direct radio contact while orbiting over the far side during Apollo 11?

Michael Collins

Michael Collins, serving as the Command Module Pilot for Apollo 11, experienced profound isolation during passes over the far side of the Moon while Neil Armstrong and Buzz Aldrin descended to the Sea of Tranquility. While orbiting in the Command Module, Columbia, the bulk of the Moon physically blocked radio signals between him and Earth. During these brief but significant periods, Collins was reportedly further from direct human contact than any other person in history. This experience contrasted sharply with the near side passes where the Earth was a constant, visible presence; over the far side, the view was only the deep blackness of space and the alien terrain of the Moon.