SARA's launch site in Marana is an excellent site for flying both high power and low power rockets, with largely open, flat terrain, nearby facilities, and expert rocketeers to help you learn to fly rockets safely. But what about sites closer to developed places for flying low power model rockets? We routinely get questions from rocketeers looking for local areas to launch model rockets. Because SARA is not present at launches outside our sponsored launches, we cannot vouch for independent fliers' safety practices, or whether the fliers have permission to fly at a particular location, so we cannot recommend specific sites. But we can provide guidance on building and flying safely, identifying a suitable flying field, and obtaining permission to fly there.
It is the responsibility of every rocketeer to learn to fly safely and legally. The National Association of Rocketry (NAR) Model Rocketry Safety Code is a set of guidelines intended to help rocketeers to develop safe habits when building and flying model rockets. Please start by reviewing the guidelines in the NAR Model Rocketry Safety Code: http://www.nar.org/safety-information/model-rocket-safety-code/. These guidelines include information about construction materials, motors, equipment, range safety, and launch site dimensions. Familiarity and compliance with the NAR Model Rocketry Safety code is required, and will help inform your decisions when flying model rockets.
The NAR Model Rocketry Safety Code outlines the minimum launch site dimensions for each motor size, under optimal conditions, and this should be considered only, a starting point in selecting a location to fly. The term 'minimum dimensions' is important here, because in real world practice, you should look for more space to safely and reliably recover rockets. In particular, do not fly close to busy public areas like soccer fields, parking lots, or near buildings like schools, businesses, or private residences. If you are pressed for space, it is better to find a launch area that borders less than ideal recovery space, such as open desert or trees, so you do not interfere with others' use of public space or risk injury or property damage to buildings or cars. Some school yards may have suitable open space, but ball fields may be in use by other users. There may be public parks that have suitable space and allow model rocketry, but check with the property manager--also known as the Authority Having Jurisdiction--before you fly.
A good first step in selecting a launch site is to measure the dimensions of the prospective launch range in Google Maps, by right-clicking one edge of the range and selecting Measure Distance from the menu. Then click the other edge of the field to display the distance. Measure the smallest dimension of the field. Once you have a prospective launch site in mind, set about obtaining permission to fly model rockets there.
While it is tempting to think it better to ask forgiveness than permission, to do so not only puts you at risk of civil or criminal penalties, it jeopardizes the continued use of public spaces for all rocketeers. Be sure to ask permission before deciding to fly model rockets, whether that is at a school field, a municipal field, or apparently unused open space. Someone owns all land, so do your homework and work to build a good relationship with the landowner or property manager. And when you arrive at a prospective launch site, even after you have permission, be sure to be friendly and communicative with other users about your plans, your impact on public space. If there are other activities at the site, cancel your plans and launch another day. Many people will be interested in your launch if you are friendly, cordial, and share your knowledge and excitement. Do your best to be a good ambassador and to maintain our hobby's reputation as a fun, safe, and educational hobby, and always aim to leave your launch site a little better than you found it. This means, at a minimum, collect any spent motor casings, igniter, or igniter plugs, and any recovery wadding you can conveniently reach. But it looks good when you are rummaging around in the desert for your wayward rocket to collect any garbage you pass.
Here are some ideas of where to look to determine the Authority Having Jurisdiction:
Step 1: Decide you want to take the step of certifying as a High Power Flier.
Step 2: Join a club and an organization!
Now you need a place to attempt the flight, and a community to support you. That is where SARA comes in!
Step 3: Review the safety codes. These are our guiding lights and are observed at all SARA launches. These set expectations and responsibilities for fliers at the field.
Step 4: Mentor program. Now you will need someone to oversee your launch, at SARA we understand that there are many questions you may have prior to certification day. That is why you should get a mentor, a mentor can help with questions about engine selection, kit selection and construction. In many cases you have a rocket that will be suitable already in your fleet!
Step 5: Read our resident super certification specialist Art Just. This article is fantastic and will help with the steps below.
Step 6: Plan your build using a rocket simulation program. You can simulate flights on different engines and make sure its stable. Art's article mentions the differences between the two programs.
Step 7: Buy neat things! After consulting with your mentor or if you are confident in research you have done.
Step 8: Build your rocket (If needed). Need help?
Step 9: Plan a date! If you do not have a mentor yet, email firstname.lastname@example.org that you would like to Level 1 and pick a launch date http://www.sararocketry.org/events
Step 10: Launch!
As a Level 3 certification holder in both NAR and Prefect for Tripoli rocketry associations, I have witnessed quite a few Level 1 certification attempts. The reason I say attempts is because there have been quite a lot of failures that would not have happened if the fliers had done the proper amount of homework, learning as much as they could about proper build techniques, stability issues, and safety.
Planning your build is the first big step. Whether you chose to build a kit or scratch build your rocket, the same basic principles apply. I always suggest that for a certification flight you keep it as simple as possible. You can always try more complicated steps after you get your certification. Motor eject, electronic eject or both at Apogee is a stronger bet than trying dual deployment or other more complicated methods. I have had several people try for their certification using dual deploy, minimum diameter, GPS tracking, and as large an I motor as they can find. Guess what, most of them failed. A simple build with single deploy, minimal electronics or none and a small H motor in a medium size rocket with 3 or 4 fins and a nose cone will be successful most of the time. Know the safety codes and stability factors, such as center of gravity compared with center of pressure and what factors affect this relationship. You need to know the weight of your rocket compared to the amount of initial thrust of the motor you choose. What is that limit? I am not going to give you all the answers, that is part of doing your homework and being able to answer correctly when the person doing your certification asks. If you don’t know the answers to these basic questions, you shouldn’t be allowed to fly. Having a safe stable rocket is our main goal.
If you are building a cardboard tube rocket with wood centering rings and bulk heads, you need to have good tolerances where your couplers and nose cone are inserted into the airframe. The reason for this is, if they are too loose, you might get drag separation when your motor burns out. The momentum of the rocket will tend to want to have the heavier pieces of the rocket keep going up, such as the nose cone. The pieces with more drag, such as the booster section with the fins, will tend to slow down faster. This is drag separation, and it will cause your parachute to deploy early causing the shock cord to zipper the airframe. If you get a big zipper, you will not pass your certification. If you have the proper tolerances, you should be able to pick up your rocket by the nose cone and not have it separate. You should be able to shake it a little and then have it separate. You can adjust the fit by using a little masking tape, if it is too loose or sand the coupler a little, if it is too tight. A little talcum powder at these separation points will help also. If you have a fiberglass rocket or if your nose cone is heavy, you will want to use sheer pins at the separation points. These are small nylon screws, usually #56, that are inserted thru holes in your airframe at the separation points. Your black power charge(s) should have enough pressure to sheer these pins and cause separation. It is important to know how much black powder to use, and the way you do that is to ground test your rocket. You want to have enough pressure to separate your rocket, but not enough to blow it up. There are websites that you can use to calculate the amount of powder so you have a safe amount to start with.
More and more kits that are being sold are made of fiberglass. This presents some build issues that you don’t run into with cardboard and wood. Epoxy will not stick to fiberglass unless it is roughed up first. By this I mean get your 40 or 60 grit sandpaper and scratch the surface of the fiberglass anywhere there is a joint with fiberglass and epoxy. If it is a thru the wall fin design, follow the manufacturer’s directions for gluing on the fins. Most will suggest that you add filets where the fin root attaches to the motor tube. This can be done either by drilling holes in your airframe and using a syringe to inject epoxy or leaving the aft centering ring off until you filet the fin roots to the motor tube. Again, make sure you have a good bond on the bulkheads for the nose cone and booster sections. These are where your eye bolts are attached for your shock cords. There is a lot of tension on these during deployment. A good way to add strength for these bulkheads is to recess them a little ways into the nose cone or booster section and glue in ¼ inch wide band of material above the bulk head. Again, scratch, scratch, scratch the fiberglass. Adding a little ground fiberglass powder to your epoxy with help to strengthen the bond. You can get this at several rocket suppliers or composite suppliers.
One way that we can all learn, especially those that are going to try for their level 1, is to talk to other members about their rockets and what has worked for them and what has not. I have personally learned a lot from talking to others and by observing how they do things. I have never run into anyone that wasn’t excited to show off what they have done and to share new ideas. I know that it is a little intimidating to go up to someone you don’t know and ask for their help. As part of the certification process, it is my responsibility to make sure the rocket is safe to fly and to make sure the flyer is aware of why he or she did certain things. I can’t do the rocket setup myself, but I can observe, and if I know that, for instance, the way the parachute is packed, it probably won’t open, I can stop them from continuing. In a case like that, I would demonstrate the proper way and then let them do it themselves. It would have been better if they had asked a fellow flyer to show them so they could do it correctly the first time themselves. If you are not sure, ask someone who knows, if you think the answer you get is not correct, ask someone else and have them explain it.
Part of launching a rocket with pretty good knowledge of what it is going to do is to run simulations. There are several programs available for this. Apogee rocketry sells one called RockSim. Another program that is free is called Open Rocket. There is a little bit of a learning curve with each of these, but the results are worth it. How high will your rocket go, will it bust the waiver? What is a waiver? All of these things are the responsibility of the flier. Know what factors affect how your rocket flies; wind, drag, shape of fins and nose cone, weight, etc., and what the affects will be.
This seems like a lot to learn for you Level 1 certification, but if you do it will be a safe and fun hobby.
NAR level 3 Number 87145
Tripoli Prefect Level 3 Number 12693
So I'll start out this mini-series in the How To section with a tour of my own work space, such as it is; it is shoehorned around kids' dress up and art supplies in the back of the TV room, but also hidden on shelves in the garage and in my closet. Like many Arizona homes, the lack of a basement puts a premium on storage space, and as you may have noticed, rockets can take up a lot of space! Yet I don't like to look at unfinished projects all the time, so I try to have a place set aside out of the way where I can leave projects to sit for a few days or weeks when I am busy on other things.
Primarily, I have a 6 foot by 2 foot folding table that I use for my low power projects--these days, mainly my competition models. Many of the boxes used in shipping rocketry supplies wind up being used as storage boxes for other supplies.
Due to the temperature fluctuations in a Tucson garage, rocket motors can't live in the garage. To store motors safely, they must be in a spark-proof container at least 25 feet from sources of open flame. In our home, that translates to the space under my desk. Black powder motors I store and organize in plastic toolboxes, and I have a tackle box full of my reload casings, brushes, closures, and other reloadable motor paraphernalia.
Then there is the question of where to paint. We are fortunate that we have largely undeveloped desert behind our house, with an easement between our house and the neighbors' yards. this lends itself well to paining, which we accomplish with the help of rebar pounded into the ground. Most rockets get painted vertically with the rebar through the motor mount, although overturned cat litter buckets serve well to hold models horizontally if needed. All this done well away from pavement and any foot traffic.
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