Absolute Solitude

Michael Collins, one of the Apollo 11 astronauts, became literally the loneliest human ever when he orbited the dark side of the moon, and lost all radio contact with Earth and his fellow astronauts for 48 minutes. Hence Collins revealed that he had very worried about Armstrong and Aldrin's safety. He was also concerned that, in the event of their deaths on the Moon, he would be forced to return to Earth alone and, as the mission's sole survivor.