But Progress 13, Progress M13, Transit 13 and Luna 13 did not.<br /><br />If you want to have logic to your superstitions then low numbers are far more unlucky than 13. Apollo 1, Soyuz 1, Ranger 1, Discover 1, Mariner 1, Zond 1, Venera 1, Mars 1 are just off the cuff examples. <br /><br />So why don't we retire the number one? because there is no logic or rationality to it. That is why it's a superstition and should be resisted.<br /><br />Jon <div class="Discussion_UserSignature"> <p><em>Whether we become a multi-planet species with unlimited horizons, or are forever confined to Earth will be decided in the twenty-first century amid the vast plains, rugged canyons and lofty mountains of Mars</em> Arthur Clarke</p> </div>