GeekDad Basics: How To Launch A Model Rocket

From the GeekDad mailbag, we’ve received the following request:

My son and I have decided to build and fly our own model rocket. However, I am hopelessly mechanically and electronically dopey. I’m bad at gluing together models. I can’t do any soldering. I’m borderline incapable of following instructions. I’ve done a bunch of searching for model rockets on the web and the results have left me confused in terms of bodies vs. fuel vs. engines, etc. And even if I ordered the right pieces I have no idea if I’d be capable of putting it together.

What is the best path for my son and I to follow where in anywhere from an hour to a half day we can get a reusable rocket up and launching and have lots of fun having it fly up into the air?

No problem! Believe it or not, you can launch a rocket 1000 feet in the air without a drop of glue or a bit of flux. It’s true that model rocketry has the potential to be complicated and difficult to get involved with, but there are plenty of basic, beginner options.

From the many manufacturers of rocket parts, equipment and sets, there’s plenty to choose from (and be confused by), but the company that a lot of people got started with is Estes. The Colorado-based company has a variety of pre-assembled rockets for the absolute beginner to kits to build for the more intermediate rocket builder. Plus, Estes has a number of “starter sets” that include everything you need to fire your rocket, retrieve it and fire it again.

All Images: Dave Banks

Thankfully, these kits are easy to find. They are available in most hobby stores, some Target and Wal-Mart stores or on the internet. This walkthrough will look at the M-104 Patriot Missile “Ready-To-Fly” set that requires no soldering, gluing and only moderate instruction following. Let’s begin!

The first thing to do is open the box and make sure all the parts are there. The M-104 set includes an already built rocket, launch pad, launch controller, parachute and wadding, engines and igniters for two flights. Everything’s here, so we’ll move on to the first step of assembly.

You can start with either the rocket or the launch pad, but the parts for the pad were closer, so I started with that. I laid them all out and then attached the legs to the hub, connected the two pieces of the launch rod by connecting the male and female parts and gently tapping the two pieces together on the basement floor to force the joint together. Finally, I added the blast deflector shield and attached the safety cap to the top of the rod, where it always belongs when not launching.

Next, I wrapped a four-inch piece of masking tape around the launch rod, about 8 inches up from the deflector shield. This will hold the rocket up so it isn’t resting on the shield. While some rockets can sit nicely and flatly with their fins on the shield, others have parts that prevent the rocket from sitting stably. The tape holds the rocket up so engine clips or igniters aren’t damaged by bumping against the deflector shield.

Now it’s time for the rocket. The first thing to do is check the fit of the nose cone to the body of the rocket. If it’s too tight, you can sand off some of the plastic in the nose cone with some high grit sandpaper. Mine was a bit loose so I added a single piece of masking tape. It’s important that the fit be not too loose or too tight because you don’t want the nose cone coming off before it’s time for the parachute deploy. Alternately, you don’t want the parachute to be locked in by too tight of a fit.

You want to be able to use your rocket more than once, so it has to be recoverable – time for the parachute. (Some smaller rockets use a streamer to slow their return.) The ‘chute is going to be attached to the rubber strip that attaches the nose cone to the body. (Protip: Cut the center out of the parachute. You will still have a controlled descent, but the rocket and parachute won’t drift as much in the wind, preventing you from chasing the thing for blocks and blocks or losing the rocket in a tree or street.)

Now you’re ready to attach the parachute. Gather the looped strings and slide them beneath the rubber strip, about an inch from the nose cone. Next, gather the chute and fold it carefully, making sure not to tangle any strings. Bring it over the rubber strip and through the looped strings as indicated in the image.

The assembly is nearly finished, but first the wadding has to be added. The wadding acts as a shield to protect your parachute from the gases and sparks during ignition and launch. The amount of wadding used depends on the size of your rocket. The M-104 isn’t that big so 4 sheets were enough – your kit should indicate how much wadding you should use. Loosely crumple the sheets into balls and insert into the rocket body. With care, fold the parachute into itself a couple of times, fold over then loosely wrap the excess strings around the ‘chute. Pack the parachute into the rocket, on top of the rubber strip. Next, place the nose cone in the rocket. Make sure when you put the parachute, rubber strip and nose cone in that nothing seems too tight. It’ll be important when the ‘chute pops that there aren’t any problems caused by too much friction.

You’ve done everything you need to do at home. The rest of the steps should take place at your launch site. Remember to choose an open, safe location and never launch when winds are stronger than 20 mph. Set your launch pad on level ground and make sure the launch rod is perpendicular to the ground (or slightly tilted into the wind).

Just prior to launch, prepare the rocket’s engine. There are many sizes of engines. Your kit will specify what size replacement you should use (for beginner engines, look for a letter from A-G on the package, specifing the amount of thrust the engine is capable of and that your rocket can safely handle). There are a couple ways that beginner rocket engines are mounted – either with a clip that holds the engine in or with a removable nozzle cap.

For demonstration only

With the engine in place, insert the joined wire end of the igniter into the small hole on the engine. Hold the igniter in place by gently inserting a plastic plug. Don’t drive it in too deeply or you risk damaging the igniter. Bend the igniter at roughly a 60-90 degree angle so the unjoined wires are more accessible. (The image to the left is for demonstration only. These steps should always be completed with the engine in its proper place inside the rocket.)

Slide the rocket down the launch rod and remove the safety cap. Stretch out the wires to your launch controller and make sure that everyone is back at least 20 feet from the launch pad. Only when you’re ready to launch, and with the key OUT of the controller, a responsible adult should attach the clips at the end of the controller to the igniter wires, as seen in the image to the right. Stand back as far as the controller wires allow, insert the safety key and begin your countdown.

Hold down the safety key and the “Ready” bulb on your controller should illuminate – this shows you are ready to launch. When your countdown reaches “liftoff,” press the launch button and watch your rocket scream towards the stars! Remove the key, replace the launch rod safety cap and chase down your rocket. If the rocket fails to launch, wait at least 60 seconds before approaching the rocket. Change out the igniter – the most common cause of failure – and try again.

Now that you have the basics covered, it will only be a matter of time before you build your own rockets, construct your own launch pad or make your own wadding. Model rocketry is a great hobby with some very avoidable dangers, but always remember: safety first. As you can see, rocketry is easily within the capability of any GeekDad, no matter what your skill level.

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