A robot from a faraway planet lands on Earth and announces it's the vanguard of an alien invasion. This episode of X Minus One originally aired on May 8, 1956.X Minus One premiered in April 1955 on NBC and ran until January 1958. Like its predecessor series, Dimension X, X Minus One featured stories by the greatest names in modern science fiction: Ray Bradbury, Isaac Asimov, Robert Heinlein, Clifford Simak, Robert Bloch, and many more.