WD-40, a yellow and blue spray often found in toolboxes, was originally developed for a military use during the Cold War. In 1953, the Rocket Chemical Company created the product to protect the skin of Atlas missiles built by Convair from rust. The name "WD-40" comes from "Water Displacement, 40th attempt," as the formula was perfected on the 40th try after 39 failures. The exact ingredients of WD-40 have never been patented and remain a closely guarded secret for more than 70 years. The development of WD-40 took place in San Diego, where three men—Norman B. Larsen, Gordon Dawson, and John B. Gregory—worked to solve a problem faced by the military aerospace industry. During the Cold War, the United States was building the Atlas missile program to counter the Soviet Union. Convair, the aerospace company, had to protect the missile's thin outer shell, which also acted as a fuel tank wall. Even a small amount of rust could jeopardize the missile's flight. Chemist Norman B. Larsen was given the task of creating a solution that could repel water and prevent the metal envelope from rusting. After numerous tests, Larsen and his team found a stable and effective formula using various hydrocarbons. The name "WD-40" reflects the number of attempts made before success was achieved. The formula proved so effective that Convair quickly used it to protect the outer skin of its Atlas missiles on launch pads. However, the product’s use expanded beyond its military purpose when employees started using it for everyday tasks, like unjamming garden tools or silencing a squeaky door. This led to the idea of packaging the formula into a household aerosol, which was first sold in 1958. The product was an instant hit, and the company doubled in size within two years. In 1969, the company changed its name to WD-40 Company, leaving behind its previous name of Rocket Chemical Company. The decision not to patent the formula was strategic, allowing the company to keep the composition a closely guarded secret. This ensured that no one could legally reproduce the product exactly, even though it meant forgoing the legal protection a patent would have provided. There is some debate about who truly invented WD-40. Historian Iris Engstrand from the University of San Diego suggests that the real inventor might have been Iver Norman Lawson, an engineer from Chicago. The similarity in the names Norman B. Larsen and Iver Norman Lawson has led to confusion over the decades about who exactly created the invention. From its original purpose of protecting an intercontinental missile to becoming a household staple, WD-40 has come a long way. The product remains one of the few everyday items that carry the memory of its 39 failures, etched into its name.