Model Rocket - History of Model Rocketry

History of Model Rocketry

In the early thirteenth century the Chinese turned black powder propelled objects, formerly only used for entertainment, into weapons of war. The Chinese ‘arrows of fire’ were fired from a sort of catapult launcher. The black powder was packed in a closed tube that had a hole in one end for escaping hot gases, and a long stick as an elementary stability and guidance system. Refinements in rocket design were made over the next few hundred years, at least on paper. In 1591 a Belgian, Jean Beavie, described and sketched the important idea of multistage rockets. Multistaging, placing two or more pockets of fuel in line and firing them in step fashion, is the practical answer to the problem of escaping earth's gravitational attraction. While there were many small rockets produced after years of research and experimentation, the first modern model rocket, and, more importantly, the model rocket motor, was designed in 1954 by Orville Carlisle, a licensed pyrotechnics expert, and his brother Robert, a model airplane enthusiast. They originally designed the motor and rocket for Robert to use in lectures on the principles of rocket-powered flight. But then Orville read articles written in Popular Mechanics by G. Harry Stine about the safety problems associated with young people trying to make their own rocket engines. With the launch of Sputnik, many young people were trying to build their own rocket motors, often with tragic results. Some of these attempts were dramatized in the fact-based movie October Sky. The Carlisles realized their motor design could be marketed and provide a safe outlet for a new hobby. They sent samples to Mr. Stine in January 1957. Stine, a range safety officer at White Sands Missile Range, built and flew the models, and then devised a safety handbook for the activity based on his experience at the range.

The first American model rocket company was Model Missiles Incorporated (MMI), in Denver, Colorado, opened by Stine and others. Stine had model rocket engines made by a local fireworks company recommended by Carlisle, but reliability and delivery problems forced Stine to approach others. Stine eventually approached Vernon Estes, the son of a local fireworks maker, but Model Missiles closed due to unwise business decisions. Estes founded Estes Industries in 1958 in Denver, Colorado and developed a high-speed automated machine for manufacturing solid model rocket motors for MMI. The machine, nicknamed "Mabel", made low-cost motors with great reliability, and did so in quantities much greater than Stine needed. Stine's business faltered and this enabled Estes to market the motors separately. Subsequently, he began marketing model rocket kits in 1960, and eventually, Estes dominated the market. Estes moved his company to Penrose, Colorado in 1961. Estes Industries was acquired by Damon Industries in 1970. It continues to operate in Penrose today.

Competitors like Centuri and Cox came and went in America during the 1960s, 1970s, and 1980s, but Estes continued to control the American market, offering discounts to schools and clubs like Boy Scouts of America to help grow the hobby. In recent years, companies like Quest Aerospace have taken a small portion of the market, but Estes continues to be the main source of rockets, motors, and launch equipment for the low- to medium-power rocketry hobby today. Estes produces and sells Black Powder Rocket Motors.

Since the advent of high-power rocketry, which began in the mid-1980s with the availability of G- through J-class motors (each letter designation has twice the energy of the one before), a number of companies have shared the market for larger and more powerful rockets. By the early 1990s, Aerotech Consumer Aerospace, LOC/Precision, and Public Missiles Limited (PML) had taken up leadership positions, while a host of engine manufacturers provided ever larger motors, and at much higher costs. Companies like Aerotech, Vulcan, and Kosdon were widely popular at launches during this time as high-power rockets routinely broke Mach 1 and reached heights over 3,000 m (10,000 ft). In a span of about five years, the largest regularly made production motors available reached N, which had the equivalent power of over 1,000 D engines combined, and could lift rockets weighing 100 kg (221 lb.) with ease. Custom motor builders continue to operate on the periphery of the market today, often creating propellants that produce colored flame (red, blue, and green being common), black smoke and sparking combinations, as well as occasionally building enormous motors of P, Q, and even R class for special projects such as extreme-altitude attempts over 17,000 m (50,000 ft).

High-power engine reliability was a significant issue in the late 1980s and early 1990s, with catastrophic engine failures occurring relatively frequently (est. 1 in 20) in motors of L class or higher. At costs exceeding $300 per motor, the need to find a cheaper and more reliable alternative was apparent. Reloadable motor designs (metal sleeves with screwed-on end caps and filled with cast propellant slugs) were introduced by Aerotech and became very popular over the span of a few years. These metal containers needed only to be cleaned and refilled with propellant and a few throw-away components after each launch. The cost of a "reload" was typically half of a comparable single use motor. While catastrophes at take-off (CATOs) still occur occasionally with reloadable motors (mostly due to poor assembly techniques by the user), the reliability of launches has risen significantly. In addition, it is possible to change the thrust profile of reloadable motors by selecting different propellant designs. Since thrust is proportional to burning surface area, propellant slugs can be shaped to produce very high thrust for a second or two, or to have a lower thrust that continues for an extended time. Depending on the weight of the rocket and the maximum speed threshold of the airframe and fins, appropriate motor choices can be used to maximize performance and the chance of successful recovery.

Aerotech, Pro-38, Rouse-Tech, Loki and others have standardized around a set of common reload sizes such that customers have great flexibility in their hardware and reload selections, while there continues to be an avid group of custom engine builders who create unique designs and occasionally offer them for sale.