Building and launching model rockets is a hobby that has been around since the late 1950s and early 1960s. Despite what many people may think, model rockets are a statistically safe hobby. Model Rocket building influences many children to become interested in the STEM fields (science, technology, engineering, and mathematics). Rocketry is not only a fun way to get kids outdoors and get their eyes off of screens, but its shown to increase engagement in much-needed science fields.
Model rocketry is an elaborate hobby with a lot of confusing information. Model engine types and sizes can be intimidating if you’re looking to have some fun with your kids. We’ve done the work for you. Follow along as we break down the basics of model rocketry for you. We will explain the basic model and engine types so you can start your new model rocket hobby today!
Model Rocket Basics:
Model rockets are small rockets made to launch from the ground and reach low altitudes. Designed for multiple uses, model rockets use single-use engines that propel them into the air.
Anatomy of a Model Rocket:
The structure of model rockets consists of the same basic components. The rockets start with the body tube, which is the main body of the rocket. The nose cone attaches to the body tube. The nose cone helps with the aerodynamics of the rocket and typically houses the recovery system for the model rocket. When a model rocket engine fires its ejection charge, the nose cone blows off of the rocket. A shock cord secures the nose cone to the rocket, which prevents the nose cone from getting lost in recovery. The rocket fins are at the back of the rocket to help stabilize the model rocket in the air. Most model rockets have a launch lug attached to the main body near its center of gravity.
Inside a model rocket, you will find a recovery system (we will touch base on this below) and the engine mount or engine hook, which keeps the model rocket engine in place.
Designing Model Rockets:
When designing a model rocket, most rocket components use numbers and letters to indicate information about those rocket components. When choosing parts for your rocket, those numbers should match. You want to be sure you’re ordering a nose cone that fits your rocket body.
Model Rocket Engine Types:
Major model rocket companies began stamping their motors with codes. These codes indicate certain information about the engine. An example engine stamp would look like A10-3T of B6-4.
The first letter in that code indicates the total impulse range. In order alphabetically, each letter has two times the impulse range of the letter before it. The impulse is the change in momentum. Impulse range is the impulse or change in momentum per unit of fuel. Most model rocket engines use black powder for propellant or fuel.
The First Number:
The first number refers to the average thrust of the model rocket engine. The higher the thrust, the higher the liftoff acceleration. Higher liftoff accelerations help heavier rockets get off the ground. A model rocket engine with higher thrust as liftoff will not burn for as long. Lighter rockets can withstand lower thrust at liftoff, and those engines will burn longer and hopefully reach higher altitudes.
The Last Number:
The last number indicates the delay in seconds between the end of the thrust phase and the ignition of the ejection charge. Model rockets with a recovery system will have an ejection charge that ejects that recovery system from the nose of the model rocket. Rockets with a “0” indicate there is no delay or ejection charge. Model Rocket engines with a “p” in this place shows the model rocket is plugged. Plugged means there is no recovery system. Instead, there is a plug or cap in place of the ejection charge.
Estes Model Rocket Kits:
Estes is a model rocket company that began in the late 1950s and grew to become one of the most popular model rocket companies in the United States. The company created a machine that was able to produce a model rocket engine start to finish in 5.5 seconds.
Estes Model Rocket Engines:
Model Rocket engines are built using a heavy cardboard tube to contain the engine components. Inside the cardboard tube are the ceramic nozzle, propellant, delay charge, ejection charge, and a clay retainer cap.
Estes model rocket engines are launched or ignited using an electrical charge from a coated wire.
Model Rocket Engine Color Coding:
In addition to a number/letter system. Estes also color codes their model rocket engines for ease of use.
These engines are used in single-stage model rockets. Single-stage rockets are lighter models that don’t require an engine booster to allow the heavier rockets to lift off from the ground.
The Estes Journey is a popular single-stage model rocket that uses the standard green Estes model rocket engine. This model rocket can reach up to 1100 feet in the air and is a great basic model for a beginner hobbyist. This kit includes the rocket, parachute, and launch controller. The green single-use engines are sold separately.
Purple engines are for very light single-stage rockets, or the final stage of multi-stage rockets.
The Estes Eggscaliber Model Rocket uses the purple engine. Students can launch an egg up into the sky using this model rocket and watch it safely parachute back down to the ground. With this model, the rocket and egg can reach up to 600 feet in the sky.
Red engines are for all engine boosters or middle stages of multi-stage rockets. Multi-stage rockets are larger and heavier rockets that require a booster engine at liftoff and intermediate or final ignitions to help those rockets reach desired heights.
The Estes Extreme 12 Model Rocket Kit is a powerful two-stage model rocket that uses the red Estes rocket engine. Using this kit, this tall model rocket can reach just under 2,000 feet in the air. This model rocket uses a 12-inch parachute as a recovery method.
Blue rockets are plugged rockets for model rockets with no recovery system or radio-controlled gliders.
The Estes Baby Bertha Flying Rocket Kit is another beginner model that uses the brown engine type. This rocket is the smaller replica of the Big Bertha for more advanced model rocket users. The Baby Bertha can reach over 575 feet in the sky.
The Estes Mini Mosquito uses the standard blue/brown engine. This model rocket uses the tumbling method of recovery and given its tiny stature can sore up to 800 feet in the sky. Estes warns that this mosquito is so tiny it can be difficult to recover but very fun to launch!
It is essential to know what type of rocket you are building to be sure you are using the correct engine type. Second stage engines that ignite after a rocket begins its descent can cause that rocket to become a ballistic projectile that can be dangerous to people and buildings below.
Model Rocket Recovery Methods:
When launching model rockets, you can recover the main body of a model rocket. Model rockets use a variety of recovery systems.
This method is for the smallest types of model rockets. The rocket flutters back to the ground and gets recovered by the user.
This type of recovery uses an ejection charge. When larger or heavier model rockets are allowed to fall back to earth, their stable design can cause them to become a dangerous projectile increasing in speed as they fall. An ejection charge ignites and causes the engine to slide into the back of the model rocket body, changing the center of mass for the rocket. The rocket becomes unstable and tumbles to the ground more slowly than if the model rocket design remained stable.
Nose Blow Recovery:
This method recovery was popular during the earlier years of model rocket use. The nose cone blows off the model rocket but stays attached by a cord. The detached nose cone disrupts the aerodynamics of the model rocket causing is to fall slowly to the ground. This method can cause damage to heavier model rockets, and it only suitable for lighter model rockets.
One of the most popular methods of model rocket recovery, this method is often used with smaller model rockets. With a bigger parachute, model rocket builders can use this method with larger model rockets. The ejection charge of a model rocket engine forces the chute out of the model rocket. The parachute, which connects to the body of the model rocket, allows the rocket to float down to the ground safely. Be aware of any utility lines near your recovery zone as parachutes can get caught on those lines.
The ejection charge deploys a wing. The wing causes the model rocket to spiral safely to the ground. In radio control gliders, the model rocket flies back to the user using a remote control.
This method is similar to glide recovery. Instead of ejecting a wing, the ejection charge deploys helicopter blades, which slow down the rocket’s descent to the ground.
Starting your Model Rocket Hobby:
Whether you’re looking to bring back the nostalgia of your childhood hobby or engage your kids in a STEM activity, flying model rockets is a hobby you and your family can enjoy together. Designing, building, and flying model rockets engage your mind in a fun and educational activity.
Recommended Model Rocket Supplies
In order to successfully begin a model rocket hobby, you may want to consider the following supplies:
- Model Rocket Launch Pad: Once you have a launchpad and controller, you can purchase a variety of rockets to build and launch from your launchpad.
- Recovery Wadding: Fire resistant paper stuffed in between your engine and your recovery system. Protects your parachutes from heat damage during launch.
- Engine Bulk Packs: Because you will be launching your rockets over and over, you want enough engines for an entire afternoon of fun!
Introduce yourself to the hobby of model rocketry and you’ll find yourself brushing up on basic science and engineering concepts to improve your hobby. Model Rocketry is a great way to bond with your kids and introduce them to the fun of the STEM fields.