‘The lunar module curved gently down over the Sea of Tranquility, the drama heightened by the calm, almost casual voices of the astronauts and the mission controller at Houston.The casualness was deceptive: from 500 ft. above the surface and all too aware that an error could lead to irretrievable disaster, Aldrin brought the spacecraft down under Armstrong’s direction. At the moment of approach Armstrong’s heartbeat rose from its normal 70 to 156. Yet his voice was calm and flat: “Contact light: engines stopped? The Eagle has landed.” The landing was perfect.’