F.A.Q.'s - Estes Rockets

Is model rocketry safe?

Yes! In fact, when the NAR Model Rocket Safety Code is followed, Estes model rocketry is one of the safest outdoor activities for kiddos and adults alike. Because of the hobby’s popularity over the last half century, it’s impossible to know exactly how many model rockets have been launched, but it’s safe to say that Estes model rocket engines are responsible for over 500 MILLION safe and successful launches since 1958. For more than 60 years, Estes has provided—and continues to provide—STEM educational materials and innovative products to people of all ages—all with equal emphasis on providing safe and exhilarating learning experiences.

How high can a model rocket fly?

Estes model rockets fly from 100 feet to 2,500 feet high! It all depends on the size and design of the model rocket and the Estes engine(s) used to launch it. Each Estes model rocket is tested numerous times, before it goes to market, to determine which engines are best for flight and the altitudes that can be reached. This information is available on the packaging for every Estes model rocket. It can also be found for each model rocket on estesrockets.com and in the annual Estes catalog.

Can I fly my Estes rockets more than once?

You bet! Estes model rockets are designed to be flown over and over again. But remember to follow the NAR Model Rocket Safety Code when retrieving your rocket. Do not attempt to retrieve your model rocket “from power lines, tall trees, or other dangerous places.” And always inspect your rocket and repair any damage before relaunching. Then complete the same flight preparation steps that you used for your first launch. Repack the rocket with recovery wadding, refold and insert the parachute or streamer, remove the used engine casing and insert a new engine, starter, and engine plug. Then you are go for launch again!

Where can I fly my model rockets?

For launch location information, review the NAR Model Rocket Safety Code. You should always check with your local AHJ (authority having jurisdiction), such as your city or county/parish government for any special regulations that may apply to your area. Generally speaking, you can fly most Estes model rockets in large, open park grounds or school grounds, such as football and soccer fields. Make sure that the launch pad is not near dry grass or weeds.

What about weather conditions?

The NAR Model Rocket Safety Code provides guidance. Model rockets are not to be launched on windy or cloudy days. You don’t want wind to interfere with your rocket’s flight or have your model rocket weathercock. And it is important to never launch a model rocket into clouds because you cannot see what might be in them.

What is the general flight path of Estes model rockets?

Upon rocket ignition with an electronically operated launch system, the model rocket engine’s propellant begins burning. This is the thrust phase, which provides liftoff and powered acceleration. After the engine’s propellant has finished burning, a timed delay charge is activated. The delay charge provides no thrust, but instead allows the rocket to coast to apogee—the rocket’s highest altitude during flight. The delay charge also provides tracking smoke so you can better see your rocket’s flight path. Once the delay charge has finished burning, the ejection charge is initiated. The ejection charge creates pressure in the rocket’s body tube that causes the recovery system—usually a parachute or streamer—to deploy. Then the rocket gently returns to earth so that it can be prepared for another launch.

How do I order an Estes catalog?

Our most recent catalog is available for purchase online, or you can browse and download all our digital catalogs!

How can I keep my rocket from drifting away?

Even when flying within the wind limits, lightweight rockets can drift significant distances. To reduce the effects of drift beyond what can be done by tilting the launch rod, the recovery system needs to be modified so the model rocket will descend at a somewhat faster rate. Various methods include:A. Cutting a spill hole: The top of an Estes plastic parachute has a circle that can be cut out. This allows air to flow through it quicker, increasing the descent rate. The drawback to this modification is that it is permanent.B. Reefing the parachute: Gather the parachute’s shroud lines together at the mid-point and wrap a piece of tape around it. This prevents the parachute from opening fully, making the rocket’s descent faster. On days when there is no wind, remove the tape. This modification is temporary.C. Switch to a streamer: Streamers generally allow the model rocket to descend quicker than parachutes do. If the rocket has a parachute, remove it and attach a streamer. Using snap swivels is a great way to make recovery systems easily interchangeable.

How do I properly install my starter in my Estes model rocket engine?

1. Hold your Estes engine upside down (as shown). 2. Insert the starter into the engine’s nozzle. The tip of the starter will be resting against the engine’s propellant. It’s important that the tip stays in contact with the propellant for initiation. a. Do NOT bend the starter; this could cause the starter tip to pull away from the engine’s propellant. 3. Continue to hold the engine upside down when inserting the engine plug. (The insertion of the plug will bend the starter wires a minimal amount, but it should not pull the starter tip away from the propellant.)4. Once the plug is holding the starter firmly in place, bend the starter wires away from each other (as shown). It is important that the starter wires do not touch each other—either above or below the tape—to avoid a short circuit. 5. Install the engine into your model rocket according to your model rocket’s instructions.

How do I get my launch controller to work?

To test your launch controller’s continuity/circuitry: 1. Make certain that you have correctly installed fresh, alkaline batteries.2. Attach your launch controller’s micro clips to each other. 3. Insert the safety key into the keyhole and PUSH DOWN HARD until the black rubber safety spring under the safety key is fully compressed. The key should now make a complete circuit and the controller’s light bulb should light up brightly. (A dim or flickering light indicates that the batteries are not fresh or new enough. Or the battery contacts in the controller may need to have battery build-up carefully scraped off.)4. While continuing to hold the safety key down HARD, press the controller’s launch button; this should make the light go off. 5. If you complete steps 1-4 and the controller responds as noted, the controller is operational and ready for use. 6. *Remember: ALWAYS keep the controller’s safety key removed from the keyhole until you are prepared to launch.

Using your controller at launch time: 1. Make certain that you have correctly installed fresh, alkaline batteries in your launch controller. 2. Make certain that your model rocket is prepared for launch on the launch pad with the correct engine and starter installed. 3. Attach your launch controller’s micro clips to the starter wires of a correctly installed starter. (See “How do I properly install a starter in my Estes model rocket engine?” a. Make certain that the micro clips are not touching each other or the blast deflector plate. 4. Make sure that your launch controller wires are fully extended (16.4 feet when launching rockets with A through D engines and 30 feet when launching with engines larger than D).5. Insert the safety key into the key hole. PUSH DOWN HARD. The launch controller’s light should light up brightly. 6. Continue to push the safety key down hard and begin countdown. “5—4—3—2—1—Launch!” a. At “Launch”, press the launch button with your other hand—all the while holding down the safety key. b. If you stop pushing down the safety key when you push the launch button, you will break the circuit, and your rocket will not launch. 7. If this still does not help please Contact Us.

What should I do if my engine fails to ignite?

If your engine fails to ignite, remove the safety key from the launch controller’s keyhole and WAIT ONE MINUTE BEFORE APPROACHING THE LAUNCH PAD.A burned starter means the starter’s tip wasn’t touching the propellant. You can usually tell that the starter has burned because the tip is no longer connected by the bridge wire. Follow the instructions under “How do I properly install a starter in my Estes model rocket engine?”

If the starter is not burned: 1. Check the launch controller’s batteries. Weak batteries will illuminate the continuity light (it may flicker or be dim), but they will not have enough power to initiate the starter.2. Check the battery contacts in the launch controller. If the batteries rattle when shaking the launch controller, the contacts (springs) have compressed. The continuity light won’t illuminate. Open the controller and spread the contacts out.3. Check the launch controller’s micro clips. Exhaust residue will build up on the clips preventing continuity. The continuity light won’t illuminate. Clean the micro clips with sandpaper or steel wool.4. If the micro clips are touching each other, the system has shorted out. The continuity light will illuminate. Separate the clips and launch.5. If they are touching the blast deflector plate, the system has shorted out. The continuity light will illuminate. Separate and launch.6. Check the starter. Usually a broken starter is indicated when the continuity light does not illuminate. If the starter wire is broken, replace it with a new one.7. If the starter wires are touching each other near the tip, the system shorts out. The continuity light will illuminate. Gently separate the wires without breaking the tip apart and reinstall the starter and engine plug.

What types for glues work best to build model rockets?

It is helpful to know that adhesives that work well with porous materials—like balsa—do not always work well with nonporous materials—like plastic. Carpenter’s glue or wood glue works well when bonding balsa and paper parts together, but it does not work when bonding plastic nose cone parts together. For bonding plastic pieces together, we recommend plastic cement.

You can also use some types of CA (cyanoacrylate) glues for bonding both porous and nonporous materials together. However, while the CA bond to plastics is good, it is not any better than solvent-based adhesives, such as plastic cement or liquid cement.

What can I do if the rocket lifts off slowly or gets stuck on the launch rod?

For a slow liftoff or rocket that hangs up on the launch rod:

1. Clean the launch rod with steel wool. Exhaust residue can build up, preventing the launch lug from sliding over it easily.2. Check the launch rod joint. If the connecting joint has a rough edge, it will catch the launch lug and prevent the rocket from passing that point. Lightly sand the rough edge until smooth.3. Check the launch lug(s) on the rocket. a. If the model rocket has only one launch lug, and it is not correctly aligned with the rocket’s body tube, the direction of the engine thrust will be different from the launch rod orientation and will cause binding. Visually check the launch lug and make sure it is parallel to the body tube.b. If the model rocket has two lugs and they are not aligned with each other, the rocket will bind on the rod and it won’t launch. This can be checked while placing the rocket on the launch rod. The rod should slide easily through both lugs.

Why do I need to use recovery wadding?

Estes’ flame-proof recovery wadding is an important component of most model rockets’ recovery systems. Model rockets that rely on parachute and/or streamer recovery need recovery wadding to keep the recovery system intact.

1. A scorched parachute– This occurs when the recovery wadding is crumpled into tight little balls and then inserted into the rocket’s body tube. This leaves gaps around the wadding permitting hot ejection gases to slip around the wadding. Instead, each piece of wadding should be crumpled into loose ball shapes before inserting them. This eliminates any air gaps. Visually check the wadding after you’ve inserted it: look down into the body tube to see if any light can be seen around the edges. If light shows through, repack the wadding.

2. Substituting tissue paper for recovery wadding—Never do this! Recovery wadding is specially treated with flame retardant. When an engine’s ejection charge goes off, it produces hot expanding gases that push the nose cone and parachute/streamer out. Recovery wadding provides a physical barrier between the ejection charge and the parachute/streamer to prevent those hot gas from melting it. If ordinary tissue paper is used, it will catch fire and burn as it floats to the ground.

My parachute did not deploy. How can I fix this?

There are several things that can cause recovery system failures:

A. Nose cone doesn’t come off. Possible problems include:

1. Too much recovery wadding or recovery wadding that is packed too tightly.2. Parachute/streamer binds in the body tube because it was not packed small enough. When preparing the recovery system before launch, the parachute/streamer should slide easily into the body tube. 3. Engine falls out of rocket before ejection charge is initiated because the friction fit engine mount didn’t hold it in. Add tape around the engine to make a tighter fit.4. Nose cone is too tight. Sand the nose cone’s shoulder. It should slide easily into the body tube. Also check that parts of the shock cord or shroud lines are not caught by the nose cone.

B. Parachute/streamer fails to open. Possible problems include:

1. Cold weather — Plastic wants to stay in its confined shape when cold. Pack the system just prior to launch.2. Hot/humid weather—This causes the plastic to stick to itself. Dust with baby powder before packing.3. Insufficient amount of recovery wadding or wadding crumpled too tightly. Heat from the ejection charge melted the recovery system causing its failure.

Can I use my older engines? How should they be stored?

Estes engines do not have a shelf life, so if they have always been stored in a cool dry place, and were not exposed to excessive humidity, and/or temperature cycling—extreme heat and extreme cold (140 degrees to 32 degrees Fahrenheit)—your engines should perform properly. However, you will have to watch for erosion of the clay cap and dark propellant showing on the sides. If the engines appear to be damaged (i.e. the casing is bulging; the casing is beginning to unwrap; or the nozzle or cap appear to be crumbling) the engines may have been subjected to temperature cycling, and you should destroy them by soaking them in water until they disintegrate and then discard them in an outdoor waste bin. *Temperature cycling can easily occur if engines are left in a car’s trunk through a winter and summer season.

How to dispose standard Estes engines

Soaking a small quantity of model rocket engines in water until they disintegrate will render the engines harmless. The non-colored paper casings will become unwound. The glue with which they are held together is organic and non-toxic. The intimate mixture comprising the propellant, delay and ejection charge will separate and fall to the bottom of the water as will the natural clay material comprising the nozzle and cap. These remnants can be safely disposed of in an outside trash receptacle. Each of the components is basically harmless alone and is not dangerous to people or the landfill in small quantities. If the components are left together to dry completely, the remnants are likely to be very flammable but should not pose a great hazard so long as they are not “remixed”.

How to dispose Estes Pro Series II composite motors

Any Estes Pro Series II composite engine (motor) may be safely disposed of by digging a small hole in the ground, placing the Pro Series II composite motor vertically in the hole, nozzle up and packing the soil back around it. The composite engine or motor should then be ignited in the normal fashion using an igniter and an electrical launch controller with 30 feet of cable. When ignited, all pyrotechnic components of the motor will be consumed. Never place any part of your body above the motor during the disposal process. You and all others should remain at least 30 feet away during the process. Do not approach the motor for 1-5 minutes. The casing may be very hot. Protect your hands with gloves or other appropriate tool when handling a Pro Series II motor after firing. The spent Pro Series II motor casing may be disposed of in any outside trash receptable and provides no additional harm to the landfill.

What do the engine codes mean?

Each engine has a letter number-number code (e.g., B6-4).

The letter indicates total impulse. This is the total power (in Newton-seconds) produced by the engine. Each succeeding letter has up to twice the total power as the previous letter. For example, a ‘B’ engine has twice the power of an ‘A’ engine.

The first number in the code refers to the average thrust of the engine. Average thrust is the engine’s average push, or how fast the engine powers the rocket to go. The higher the number, the faster the speed. Higher thrust engines may be the best choice for heavier models or models with higher drag factors such as a larger diameter.

The final number in the code gives you the timed delay in seconds between the end of the thrust phase and the ignition of the ejection charge. Selecting the correct delay allows your rocket to reach apogee which in most instances is the best time for the recovery system to be deployed. Engine codes ending in ‘0’ have no timed delay and are used for booster stages and special purposes only. Engines ending in ‘P’ have no timed delay or ejection charge and the forward end is “Plugged” so that no hot gases are released from the forward end.

More Information

Why doesn’t my rocket need an engine hook?

Many Estes model rockets are designed without an engine hook. Instead they rely on friction fit to hold the engine in place. If an engine is too loose in a model rocket that utilizes friction fit, a piece of masking tape can be wrapped around the engine to make it fit more tightly. The engine should not fall out of the rocket during flight—unless designed to do so, as in featherweight recovery model rockets.

What is engine clustering?

Engine clustering is using two or more engines (or the simultaneous ignition of more than one engine in a model) in a cluster to provide greater thrust for single or first stage liftoff and acceleration of rockets and rockets with payloads. NASA used this technique to launch the Saturn I and Saturn V among others. Generally, a model rocketeer should use a maximum of four engines in a cluster, since more engines make ignition less reliable.

A successful engine cluster must be carefully set up. The thrust of the engine arrangement must be balanced around the centerline of the rocket, or the rocket will veer off course. Similarly, all engines away from the centerline should have the same thrust. Also, all engines should be located close together.

Ignition is the most important part of clustering. All engines must ignite at once or within fractions of a second of each other. The only ignition system proven safe and reliable is direct ignition using standard igniters. This is done by linking igniters together in a parallel manner so that each engine is ignited at the same time without igniters burning one by one.

Unusual engine arrangements should be developed carefully. If the thrust is out of balance, or if ignition is not successful in every engine, the rocket may fly off course making it unsafe.

More Information (pages 21-24 of “The Classic Collection”)

What is a multistage rocket?

A multistage rocket is one that uses two or more engines that ignite consecutively (one after another) to propel a rocket higher and faster. Lower and intermediate stages always use engines that have no delay or tracking smoke and no recovery system ejection charge. The absence of a delay charge allows the next engine to receive the maximum velocity from its propellant burn. These engines are referred to as booster engines and they are coded with a zero where the delay charge is noted (i.e. C6-0).

In the upper final stage, an engine with a delay and tracking charge and recovery system ejection charge is used. An engine with a long delay should be used as the rocket must lose velocity before activating the recovery system. This will give you greater altitude and avoid damage to the recovery system.

Before attempting to build a multistage rocket, you should build and fly several single stage rockets to familiarize yourself with the principles involved. The reliability of a two stage rocket is always less than a single stage rocket; as more stages are added the reliability becomes less. Hence, more building and flying skill is required as model rockets become more complex.

More Information (pages 3-6 of “The Classic Collection”)

How do I prepare my multistage rocket for flight?

Most Estes multistage model rocket kits come with specific instructions to follow. However, the following are general multistage instructions: *Note—the bottom of an engine is the end where the nozzle is located. Use cellophane tape to connect the top of the booster engine to the bottom of the upper stage engine. If needed, wrap masking tape around rear of upper stage engine and front of booster stage engine to friction fit into the engine mount. Push upper stage until it stops against engine block and fits snugly.

The balsa fins won’t stay on my rocket when I glue them. How can I keep them on?

To keep the fins on until the glue dries:A. The best glue to use is carpenter’s wood glue. This glue will dry quicker than most other glues.B. Fin gluing techniques:

1. To create a tight bond, first apply a thin layer of glue to the root edge of the fin and work it gently into the pores and grains of the wood.2. Repeat this for all the fins.3. By the time you finish the last fin (1-2 minutes), the first fin has become tacky if not nearly dry. Apply another thin layer to the first fin.4. Hold the fin’s rear part of the root edge in position on the body tube and with gentle pressure, angle the fin’s root edge up against the body tube until the entire root edge has made contact. Hold the fin in position for 10 seconds. This gradual attachment action acts like a squeegee to force out any trapped air at the connection. Any air pockets not pushed out weaken the joint.5. Release the fin and you’ll find it secure.6. It is best to hold the rocket vertically when the fins are drying. Stand the rocket on its nose (without the nose cone in place). Use heavy objects, such as books, to prop the rocket in this position.

To learn more about model rocketry visit the Teachers and Educators section. There you’ll find tons of educational resources and publications!