Model Rocketry State of the Sport - 2012/06
by John Boren
Overview
Like all hobby activities that require time and patience to build or fly, model rocketry has seen a decline in youth participation. Many of the old-time rocket fliers have moved on to other hobbies after raising their families, which is a shame because they are missing out on the developments of the past 20 to 30 years.
When I first started building models, my local hobby shop carried the two major brands at the time: Estes and Centuri. That shop stocked small A- through D-size black-powder motors by Estes. If you wanted something out of the ordinary from the handful of smaller rocket companies, you had to request a catalog, fill out an order form, and mail it with payment.
Today, with an Internet connection in nearly every household, a vast array of model rocket companies can be accessed and supplies purchased with a few clicks. I still suggest visiting your local hobby shop first — much of what is available online can also be bought there.
Rocket types and construction
A model rocket can be as simple as a cardboard-tube body with thin-cardboard fins and a simple nose cone, or a fully molded carbon-composite rocket that costs thousands of dollars to construct. Most rockets fall somewhere in the middle.
For very small rockets you can still buy an Estes 1/4A motor that produces slightly more than a half newton-second (N·s) of impulse. Rocket scientists use impulse and thrust to describe motor performance; for those who believe bigger is better, motors such as the P-150 put out more than 40,000 N·s of impulse (roughly equivalent to about 1,900 pounds of peak thrust at launch) — not too shabby for a model!
Longtime modelers may have been inspired by NASA's moon program or by Cold War-era interest in high-speed aerospace technology. As airplane modelers recreate Piper Cubs and P-51 Mustangs, rocket modelers recreate military and manned space vehicles.
Getting started: launch sets and RTF models
Whether you are new to model rockets or returning to the hobby, buy a launch set that includes at least one model kit, a launch pad, and a launch controller. Today you can even purchase RTF (ready-to-fly) rockets in complete launch sets. Both Estes-Cox Corporation and Quest Aerospace offer complete outfits with easy-to-assemble kits or RTF models.
If your flying field is small, choose lower-impulse motors (A- or B-class). Each letter jump in motor classification (for example, A to B) roughly doubles the total impulse — meaning the rocket can go roughly twice as high and may need a larger flying field to retrieve.
Model components and recovery
An RTF model rocket consists of:
- the model airframe (diameter, length, fin number/shape, nose cone type),
- a recovery system to bring the model down safely, and
- protective material to shield the recovery system from the motor’s ejection charge.
Common recovery types:
- Parachute — the most popular and widely used across sizes.
- Streamer — common for smaller models.
- Tumble recovery — for very small, lightweight models.
- Helicopter (blade-deploying) recovery — blades deploy to rotate and slow descent.
- Glide recovery — the model glides; you can use a micro radio unit to search thermals.
Recovery wadding protects parachutes and other recovery devices from hot ejection gases. Wadding is typically a chemically treated paper product that resists ignition.
Motors: black powder, composite, and reloadables
The most widely available motors for small-scale models are black-powder motors (Estes and Quest currently manufacture these in the U.S.). Vern Estes developed the first automated machine capable of producing reliable black-powder motors.
Higher-performance motors use composite propellants (commonly ammonium perchlorate mixed with a rubber binder), producing a grain with a texture similar to a pencil eraser. These composite motors are chemically similar to the solid rocket boosters used on the U.S. space shuttle.
Advantages of composite motors:
- More power for a given motor size compared to black-powder motors.
- More consistent performance.
- Larger impulse options.
Reloadable composite motors
For larger impulse motors, the vast majority of composite systems use reusable outer aluminum cases — these are reloadable motors. Buy a case size that suits the models you intend to fly and use reload kits containing the propellant grain, nozzle, O-rings, and other parts needed to turn the aluminum case into a flight-ready motor. Reloadables can lower the price per flight and give you a wider choice of propellants and visual effects (colored flames, different burn characteristics).
AeroTech Consumer Aerospace and Cesaroni Technology offer complete lines of reloadable composite motors from D up to P size, with many propellant types and visual effects available.
Building skills and progressing
After flying the models that come with a launch set, you can build hundreds of available kits. Many companies classify kits by skill levels from 1 to 5 (1 is easiest, 5 most difficult). Popular models over the past 50 years have often been simple skill-level-1 kits, but skill levels help match projects to your experience and tools.
If you want to reproduce a long-discontinued kit, Semroc Astronautics Corporation offers many parts to recreate vintage models.
For larger rockets:
- Estes offers kits and motors in the F- through G-powered range.
- For diameters over about 7 inches and very large models, LOC Precision offers heavy-duty kits capable of handling K-class motors and larger.
Competitions and organizations
You can compete in many contest events. The National Association of Rocketry (NAR) is the hobby’s national organization (the model-rocket equivalent of AMA). Along with its bimonthly Sport Rocketry magazine, NAR supports clubs, education, contests, and publishes the Model Rocket Safety Code. Check the NAR website for resources, events, and safety information.
—John Boren [email protected]
Transcribed from original scans by AI. Minor OCR errors may remain.
