The space race came down to one loose bolt

Russia had developed the N1 Rocket as the counterpart to the U.S. Saturn V. During a test launch of the N1 on July 3, 1969, a single loose bolt got sucked into a fuel pump, resulting in one of the largest non-nuclear explosions in human history. Seventeen days later on July 20, Apollo 11, launched by a Sautrn V rocket, became the first manned mission to successfully land on the moon.