Amateur rocketry, sometimes known as experimental rocketry or amateur experimental rocketry, is a hobby in which participants experiment with fuels and make their own rocket motors, launching a wide variety of types and sizes of rockets. Amateur rocketeers have been responsible for significant research into hybrid rocket motors, and have built and flown a variety of solid, liquid, and hybrid propellant motors. History Amateur rocketry was an especially popular hobby in the late 1950s and early 1960s following the launch of Sputnik, as described in Homer Hickam's 1998 memoir Rocket Boys. One of the first organizations set up in the US to engage in amateur rocketry was the Pacific Rocket Society established in California in the early 1950s. The group did their research on rockets from a launch site deep in the Mojave Desert. In the summer of 1956, 17-year-old Jimmy Blackmon of Charlotte, North Carolina, built a 6-foot rocket in his basement. The rocket was designed to be powered by combined liquid nitrogen, gasoline, and liquid oxygen. On learning that Blackmon wanted to launch his rocket from a nearby farm, the Civil Aeronautics Administration notified the U.S. Army. Blackmon's rocket was examined at Redstone Arsenal and eventually grounded on the basis that some of the material he had used was too weak to control the flow and mixing of the fuel. Interest in the rocketry hobby was spurred to a great extent by the publication of a Scientific American article in June 1957 that described the design, propellant formulations, and launching techniques utilized by typical amateur rocketry groups of the time (including the Reaction Research Society of California). The subsequent publication, in 1960, of a book entitled Rocket Manual for Amateurs by Bertrand R. Brinley provided even more detailed information regarding the hobby, and further contributed to its burgeoning popularity. At this time, amateur rockets nearly always employed either black powder, zinc-sulfur (also called "micrograin"), or rocket candy (often referred to as "caramel candy") propellant mixtures. However, such amateur rockets can be dangerous because noncommercial rocket motors may fail more often than commercial rocket motors if not correctly engineered. An appalling accident rate led individuals such as G. Harry Stine and Vernon Estes to make model rocketry a safe and widespread hobby by developing and publishing the National Association of Rocketry Model Rocket Safety Code, and by commercially producing safe, professionally designed and manufactured model rocket motors. Model rocketry