How To Get Involved with High Power Rocketry
You may be familiar with launching small model rockets, you either launched one as a kid, or you still build the kits for fun. However, you may not be familiar with high power rocketry, which involves much bigger rockets, and much larger motors. If you are interested in getting involved with high power rocketry, even if you never launched a low power rocket, it's easier than you think to start at the high powered level.
In this How-To, I will introduce you to high power rocketry, how to build, get certified, launch and much more. I will also introduce you to costs associated with it, which vary depending on how much fun you want to have.
What makes a high power rocket high power?
According to the National Association of Rocketry (NAR), model rocketry is put into 2 classes, low and high power. What characterizes a rocket of either class is the total thrust & burn time (known as total impulse) of the motor. Depending on the amount of total impulse, the motor is given a letter to designate how much it has. For example, a motor with an "A" designation, means that the motor has between 1.25 - 2.5 newton-seconds (N-Sec) of total impulse. As you go up each letter of the alphabet, the amount of max impulse doubles, which means B=5, C=10, D=20, and so forth. The table below shows the impulse ranges for all motors in both low and high power classes. The low power range goes from the A-F, and anything above that is considered high power. The high power range goes from G-O (a range from 160 N-Sec to 40960 N-Sec!), and is split up into 3 levels.
Ok, so I want to launch high power, where do I start?
To start launching high power rockets, you will need to gain a certification through NAR in the level 1 category (we will go into certification detail later), which means succesfully launching and landing a rocket with a H or I class motor. Let us start by finding you a place you can buy a high power rocket.
Where to buy high powered model rockets
There are many well known brands out there which make nice and stable high power rockets. Below are the places that I would recommend you look into for buying your first high powered rocket. I'm not here to complicate your life with too many choices, so I am only referring you to a couple of websites that I have either purchased product from, or I have heard is reliable:
LOC Precision - I highly recommend them! This is where I bought my first high power model, the Norad Pro-Maxx. I bought it simply for the reason that I though it looked cool, had a payload bay, and it handled a wide range of motors from F - J. *Website tip: To find out what motors each rocket can accomodate, click on the photo of the rocket on the product page to enlarge it, and it will tell you what motors you can load.
Apogee Rockets - Very cool website with a lot of great rockets, and resources on getting started in model rocketry. They also have a section on how to get certified in high power launching you should check out.
Aerotech - Not only are they one of the leading high power motor manufacturers, they also make their own line of high power rockets. I have not personally bought a rocket from them, but I would imagine you could find something good from them.
Madcow Rocketry - Have not personally bought anything from them, but I see people launch rockets from this company all the time, especially the Nike Smoke. They do not tell you what motor class will work for the rocket, but they do specify the motor mount sizes. Most H-J class motors will require at least a 38mm motor mount, so find a model that has that size. Again, if you are not sure, ask questions!
Building a High Power Rocket
One fin in, three more to go
You have bought the rocket, now time to build it, which will be very difficult... Just kidding! Building a high power rocket is easier than you might think if you have never done it. There are not too many unique parts that make a high powered rocket more complicated to build than a low power rocket. In fact, I would argue a high power rocket can be less difficult simply by the fact that since parts are bigger, they are easier to handle when gluing and aligning parts. Most kits will come with a set of instructions to build them that should be fairly easy to follow along. If you have any questions about the kit and how it is put together, I recommend talking to someone from the kit manufacturer. Rocket manufacturers are always available to talk to via email, so take advantage of that! Although construction is typically easy, take your time to make sure when gluing fins and other parts together that you have them aligned and you are not skipping recommended steps to rush the process. Be aware that the glue you will be using for these kits is an epoxy, so when you glue something, it likes to stay glued! Also, if you use a 5 minute epoxy, that does not mean the epoxy is good and dry after 5 minutes, and you can move on to the next step. The epoxy has hardened slightly, or set itself, but it still usually takes 24 hours to fully harden (or cure). Allow yourself some time to build it right the first time, and do not waste your money.
The Cost
Speaking of money, you may be interested at this point to know how much this hobby can cost before going on a shopping spree buying rockets, so this next section will give you an idea of what it could cost. If you are not careful and have way too much fun (which is easy to do) this hobby can get expensive quick. I highly recommend keeping tabs on everything you spend related to it. The first table below represents actual costs of the model I bought, plus building supplies, and additional build items suggested to me by others that I purchased before my certification flight.
Of course, you may be familiar with how to get certain things mentioned above for cheaper, or you already have them, in that case, great! You have reduced your cost or have taken away part of your cost. In case you are not familiar with some of the things mentioned here and how they are used, I will try to explain. The "Build Costs" section consist of the rocket model kit, and the basic things needed to put it together, epoxy, sand paper, and paint (wood filler was only used to provide a smoother aerodynamic surface across the fins, so technically it is optional). The "Additional Build Item Costs" section consist of things that I added to the model in order to accomodate reloadable motors and protection for the parachute system. Instead of using wadding, which is a substance used to protect your parachute system from burning when the motor ejection charge goes off, I opted for a fire-resistant nomex blanket which is reusable. The rest of the items are part of the reloadable rocket motor system, which will be discussed later.
This second table below is the cost on the day of my certification launch. In order to certify, you must be a NAR member, so I paid for my membership that day. I launch with a club, and the club charges an additional launch fee of 10 dollars. I bought my Cesaroni motor from a vendor on site that day as well.
In total, adding both build cost and first launch cost, I spent around 300$ to certify.
After the certification launch, your next launch cost will be significantly cheaper. You will buy a new motor for the next time you launch, and pay any launch fee the club might have. If you look at the "First Launch Costs" table, you will see my second flight only costs 42 dollars since I have already paid the annual membership fee.
Motor Retainer and Reloadable Motor System
Aero Pack Motor Retainer SystemFor my high power model, it did not have an engine block that the motor fits into. Instead, the build instructions suggested I secure the motor by wrapping 1/2 inch wide masking type around the nozzle end of the motor until it is the same diameter of the motor mount tube it supposed to fit, then you compression fit the motor into the tube and it should stay. I am not a big fan of wrapping masking tape and shoving the motor into a tube, just seems really sloppy and a waste of tape. I was told by a friend of mine about the Aero Pack Motor Retainer, and its awesome! Since I have a 38mm motor mount tube in my rocket, I installed a 38mm retainer assembly, which consists of two pieces of machined aluminum. One part of it is adhered to the motor mount of your rocket with JB Weld, and the other is a cap which screws on over it. JB weld is used as the epoxy here and not a generic brand because this portion of the rocket is exposed to the high temperature of the rocket exhaust, and the epoxy must withstand higher than normal temperatures. This retainer system makes reloading your motor very simple by inserting the motor and its aluminum casing right into the rocket, and the screw on cap holds the motor in place.
So far, I have been using Cesaroni brand motors in my rocket, and they have been excellent. To learn more about this system, please watch the video below. The Cesaroni 38mm system consists of two main parts, a plastic casing which holds your propellant and ejection charge, and the aluminum casing which fits over that and screws into it. For my certification flight, I flew a 276H152-15A (This means it has a total impulse of 276, which makes it an H class motor, with a total thrust of 152, and a delay charge of 15 seconds which is adjustable). This motor is also known as the "Blue Streak" since the burning propellant produces a visible blue flame and white smoke as it exhausts.
for more information on the motors and retainer, please visit the Cesaroni and Aero Pack websites.
Note: Aerotech was mentioned earlier as another motor manufacturer. I opted for the Cesaroni system instead, because the propellant and aluminum casing is a simpler system, and is a less expensive system for your first couple of launches. When using Aerotech reloadable motors, the propellant requires some setup, and does not come assembled like a Cesaroni motor. However, if you launch very often, the advantage of Aerotech is that the propellant is slightly cheaper, so you will save money going the Aerotech route after maybe 5-7 launches.
Learning more from your rockets
Marsa54 Flight Computer
I am a big fan of learning, so I treat high power rocketry as more than just a hobby, but something I can learn something useful from. There are a lot of great small electronics units you can buy where you can figure out altitude, speed, acceleration, and much more from your rocket, and at decent prices. I will only name a couple that I feel you can get a good amount of data from. These are the companies I suggest looking at:
Marsa Systems - I just recently bought an excellent compact flight computer called the Marsa 54 (pictured above) for about $225. The Marsa54 system tracks info on peak altitude from the onboard accelerometer and barometer, plus peak and avergae velocity and acceleration. It will also tell you what time your motor burns out, and the time of barometric, and accelerometer apogee. All of this data can be viewed immediately after the flight with the built in LCD. You can then view graphical data on your computer, where you can see how the flight progressed through time. There are also 4 pyro channels, and telemetry connection for 2-way telemetry interfaces. I will be launching this system on my Norad for the first time very soon!
Eagle Tree Systems - For one of the best systems I have seen (but a little pricey), you can buy the seagull high power rocketry package, which goes for around $459.99. It includes a lot of what the Marsa54 system has, but also has GPS location and telemetry so you can watch how the flight progresses in real time. A little bit pricey for me, but a very cool system to have.
Jolly Logic - The system will pale in comparison to the others, however, for a very simple/inexpensive system that you can get a lot out of, I recommend the Altimeter 2 for 69.95. It is a very small system (.47" x.64"x1.94") that can track data on max velocity, burntime, flight time, max and average acceleration, altitude at apogee and more. All of it is also readable via an LCD screen, and rechargeable via USB. The only downside is that you cannot download this data to a computer, or you cannot graphically see how the rocket data changes through time. This may be a great option for the not so serious hobbyist who may want to get a good estimate how their high or low power rocket is performing.
Launching with clubs
The best thing you can possibly do to get started, is get involved with others in a group who also launch high powered rockets. You will learn a lot more with others than you will alone. Launching with a club is the best way to go for a 2 big reasons:
1. No paperwork! Clubs take care of all FAA waivers and other regulations, and are usually insured through NAR or some other organization. All you need to do is pay a small fee to launch, and have fun launching.
2.*Extremely Important Reason* You get to learn from other experienced club members their recommended build and launch techniques that may save you from destroying your rocket. The experience of other members saves you heartache and money loss, which means you will keep enjoying this hobby for a long time.
Here in San Diego, CA for example, a local group called DART Rocketry conducts low power launches every 2 weeks, and when I launched low power rockets I would make the trip out to launch with them. About an hour away from where I live, a chapter of Tripoli meets to do high power launches. They are the group I did my certification flight, and launch with currently. Everyone that I have met from the group has been extra helpful and nice, and just by walking around and asking questions, I have learned a lot.
How to get certified to launch high powered model rockets
Cert. launch pre-launch rocket inspection with Tripoli San Diego President Paul Snow
After you have built the rocket, you must now go through the level 1 certification process. Here is a link to the NAR website, and their level 1 certification procedure. I highly suggest going onto that website and being familiar with the information there, but here it is in a nutshell:
1.Must be at least 18 to certify (sorry young ones).
2. Certifier must build a rocket (model or scratch built) that can fly on an H or I motor, and have some sort of parachute or other "active recovery" device.
3. You will need to be a NAR member by filling out a NAR Membership Form, and paying the membership fee. In addition, you will have to fill out a NAR High Power Certification Application.
4. A certification team made of 2 individuals who are already High Power certified and NAR members will conduct a safety inspection of your rocket, and also fill in parts of your High Power Certification Application.
5. You will launch your rocket, and your certification team will watch to make sure that parachute deploys properly, and it comes down safely and everything is intact. At any point during the flight if something comes off or becomes dislodged (nose cone comes off, loose fin etc.), the certification is a failure. If successful, the certification team will fill out the rest of your Certification Application that states you conducted a safe flight.
6.All paperwork is submitted to NAR and you will receive a Level 1 certification card in the mail that looks something like this:
I blocked out some info. Why? Cuz yur a stranger ;)
Hopefully now you will realize there is not much to certification. I stress again this is certifying "in a nutshell," so please refer to the NAR website since things may change, or talk to the group you launch with about how they conduct certification flights.
IN SUMMARY! Here is what I suggest you do to launch high powered, in a set of actionable items
1. Buy a pre-made, high power kit from one of the reliable sources mentioned above
2. Take your time and build the rocket right!
3. Join and become familiar with a local group that conducts high power rocket launches, and ask lots of questions! Consider making this step 1...
4. Find people in the group that can help you certify (if not sure, talk to the president of the group and he may be able to help you find people).
5. Launch! Get the card!
Boom...done.
Do you have any questions/suggestions related to this post? Please post a comment or feel free to email me directly at dminuszero@gmail.com.
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1 Comment
Reader Comments (1)
Derek,
Very nice article--and thanks for mentioning Jolly Logic's AltimeterTwo.
Nice flying!
--John Beans, President
Jolly Logic
www.jollylogic.com