The first manned rocked, bound for the Moon, has just launched from the Sprodj Atomic Research Centre in Syldavia. On board are Tintin, Snowy, Captain Haddock, Professor Calculus, and the engineer Frank Wolff. At the Centre, intense efforts are being made to establish radio contact with the rocket's passengers out in space. Tintin and his friends have fainted from the acceleration on launching. Their recovery is anxiously awaited. The wireless masts stand sentinel in the night sky, but they receive no message...