Rocketry Planet

In my youth, nothing excited me quite as much as spaceflight. When Neil Armstrong's boots first pressed into the lunar soil in 1969, I was right there with him, like millions of other children, dreaming of the day when I could step beyond my imagination and make the trip for real. By age 11, I was a passionate rocketeer, building fleets of model rockets and launching them every other Sunday in the parking lot of the local baseball stadium.

But I burned out on model rocketry in my early teens when I realized that the National Aeronautics and Space Administration owned the monopoly on getting to space. Amateurs could not hope to compete, and, indeed, few even tried.

Today, however, amateur rocketry is undergoing a renaissance. Exciting new developments in ultralightweight materials and powerful rocket motors now give amateurs all the tools they need to venture toward the final frontier. And people are responding. At least one rocketeer's creation recently reached an altitude of 36 kilometers, and other attempts to fly small payloads to 100 kilometers are tugging on the coattails of space with rockets that cost just a few thousand dollars.

To hasten the progress of such enterprises, a nonprofit group called the Foundation for the International Nongovernmental Development of Space (FINDS), based in Washington, D.C., has just announced a competition that could spark a small revolution: FINDS will pay $200,000 to the first amateur team that can loft a two-kilogram payload to an altitude of 200 kilometers. (The second group to accomplish this feat will win $50,000.) That announcement has started a citizens' space race, one that is open to anyone with the desire to participate. This month's column points the way for interested amateurs to get involved quickly and safely.

Safety is an important concern. A rocket motor, after all, burns a volatile fuel together with a separate oxidizing agent to produce gases at dangerously high temperatures and pressures. These gases blow through a nozzle at the rocket's tail and, in one of the most visible displays of Newton's law of action and reaction, propel the rocket forward. The fuel and oxidizer may be liquid or solid, or a combination of both. The space shuttle's main engines, for instance, combust liquid hydrogen with liquid oxygen, whereas its solid-rocket boosters burn a stiff matrix of synthetic rubber and aluminum powder, with ammonium perchlorate grains as the oxidizer.

Much smaller solid-propellant motors operating on the same principle are commercially available from several companies. These devices range in price from a few hundred dollars to more than $100,000. Potent motors can also be made at home for only a small fraction of the cost to industry; a few thousand dollars might fund one large enough to go after the FINDS prize. But building your own motors could be lethal without expert guidance. Thank goodness, therefore, for the Reaction Research Society, an amateur group headquartered in Los Angeles. That organization, which has been developing and testing rocket motors of all kinds since 1943, boasts a perfect safety record. It offers a complete course in solid-rocket motor construction, and anyone who wants to survive the challenge of hands-on motor making would be well advised to take it. The three-day course costs $475 and culminates with the students firing their homebuilt rocket motors on the society's testing range, which is located in California's Mojave Desert.

If you want to experiment with liquid-fueled rockets, check out the Pacific Rocket Society, also run from southern California. Its members have been experimenting with liquid propellants for more than 50 years and can give you practical instruction with these kinds of engines. They are currently assembling their most powerful creation ever, a two-stage, 10-meter, 300-kilogram monster dubbed the Exotron. Built by the society's president, Roderick Milliron, and Ian Furlong, the Exotron might become the first amateur rocket to fly into history. They anticipate shooting for the FINDS prize in January 1998.

Constructing a heavy-duty motor is only part of the challenge. The winning rocket must be stable enough to avoid tumbling over in the first few seconds, when it is traveling too slowly for the stabilizing fins to do their job. Also, it must not veer too far from the desired flight path even as it plows through the powerful winds in the upper atmosphere. And it must survive the vibration and stress of flight. The best way to design a vehicle that can take on these rigors is to learn from the experts.

One source of help is the Tripoli Rocketry Association in Bessemer, Ala. Tripoli is perhaps the world's premiere rocketry organization. It schools and certifies its members in the art of making and safely flying high-powered rockets. Tripoli organizes regular gatherings, at which devotees of the sport fire their often spectacular handiwork at so-called LDRS launches (the acronym stands for "large and dangerous rocket ships").

What strikes me most on reading Tripoli's magazine, High Power Rocketry, is that so many firms sell sophisticated rocketry supplies. One of these companies, Rocketman Enterprises, in South Bloomington, Minn., is headed by the most colorful rocketeer I know: Ky Michaelson is a 59-year-old stuntman who attaches rockets to everything from skates to motorcycles. This past summer he attempted to send a two-stage, 136-kilogram vehicle to 192 kilometers, just shy of the FINDS target. The second stage failed, but the first stage reportedly accelerated to Mach 2.6 (2.6 times the speed of sound) and topped out at nearly 24 kilometers.

The current record for verified altitude obtained by an amateur rocket is owned by the Hyperion I and its designer, Korey Kline. Kline, a Tripoli member for more than 15 years, is director of research at Environmental Aeroscience Corporation in Miami. His company specializes in fabricating rocket motors for commercial and hobby use. Kline is an expert on what are known as hybrid motors, which combine solid fuel with fluid oxidizer. His creation, a cylindrical tube 15 centimeters wide by 5.5 meters tall, was powered by such a hybrid. Launched on January 7, 1997, from the NASA Goddard Space Flight Center's Wallops Flight Facility, the Hyperion I devoured its 48 kilograms of propellant in just 15 seconds, passing Mach 3 before coasting upward to 36 kilometers. Kline is currently building a beefed-up version, the Hyperion II, to aim for the FINDS prize. If all goes well, he intends to launch late in 1998.

A fundamental problem that Kline and his rockets face is atmospheric drag, which increases drastically as the velocity rises (drag is in fact proportional to velocity squared). By achieving its maximum velocity quickly, while it is still low in the atmosphere, Hyperion I expended a great deal of energy battling the air around it, energy that would otherwise have lofted the rocket much higher.

John M. Powell of JP Aerospace in Davis, Calif., sidesteps this problem by avoiding most of the atmosphere altogether. Powell is a computer programmer and lifelong space enthusiast who delights in his group's motto: "America's other space program." Powell and his companions have spent much of the past 18 years systematically developing an ingenious system to launch rockets from weather balloons, a trick pioneered by NASA. Although Powell's tests have so far been restricted to low altitudes, he believes he can ultimately launch his existing rocket from 30 kilometers (about 100,000 feet) to a height of 80 kilometers. He intends to capture the FINDS prize by scaling up his operation and then to use the money to develop a system that can put small payloads into orbit.

Although the FINDS prize is meant to stimulate advances in rocket technology, the new amateur space race also needs electrical engineers, radio hobbyists and science enthusiasts of all stripes who want to help build and fly useful payloads. After all, without proper instruments, amateur rockets--whatever altitudes they may reach--will remain little more than especially flashy Roman candles. So if you think you have something to contribute, find a rocketry group and get involved; there should be plenty of them out there vying for the FINDS prize. Even the Society of Amateur Scientists is gearing up to join this new amateur race into space.

To get involved, consult the Society for Amateur Scientists's World Wide Web site. You may also write the society at 4735 Clairemont Square, Suite 179, San Diego, CA 92117, call (619) 239-8807 or leave a message at (800) 873-8767.