AboutDave Landgraf Expertise I will be happy to take on questions about low-power rocketry in general, including rocket design, operating characteristics of blackpowder motors, low-power motor selection, rocket construction, aerodynamics, parachute and streamer duration competition, boost glide (and a little rocket glide), egg loft, altitude competition, and scale competition. I can help you with Barrowman stability calculations, but I am not a rocksim user. I know the basics of mid-power rocketry and small composite motors but I don't fly them much (I'd rather stretch my money by sticking with low-power). I believe I can explain many concepts in a way that just about anyone can follow (and maybe even over-explain?). I absolutely do not mind "newbie" questions one bit; the only bad question is the one you don't ask!
Experience I have flown model rockets for some 40 years, including a few early years of NAR competition. I have been active at the local club level as well as in the NAR. I enjoy designing and developing unconventional designs (the kind of thing you look at and say "it won't fly!").
Organizations National Association of Rocketry
Publications Model Rocketry (magazine)
Education/Credentials I am an aerospace engineer who has worked professionally in the field for over 30 years. I have worked often with local school, church, and scout groups to lead introductory build-n-fly sessions.
Question Hello,
I have a son who is turning 8, and we are looking for a fun idea for his birthday party. Is there anything in terms of shooting-off rockets that you could recommend that would be fun for that age, yet safe with adult guidance? Thanks for any help.
Melissa (please email )
Answer Wow, Melissa, you have picked one of the best parent-child hobbies you could find. You can keep it simple and have a little fun, or you can get deeply involved, perhaps even inspire your child toward a future career in science and technology.
Probably one of the best ways to get started in model rocketry is to buy an Estes Starter Set. You should be able to find one for around $20. The kind of Starter Special that you want is a set that includes a launch pad, a launch controller (the battery-powered electrical system for igniting motors), and a model rocket. Some of the Starter Specials used to include a couple rocket motors; if you cannot find one like that you may have to purchase motors separately. Don’t forget to pick up some fresh batteries for the launch controller.
Where can you find these Starter Specials? Look in your local Walmart, or Hobby Lobby (if you have one close), or even Michaels craft store (some carry model rocket supplies, some don’t). If you go to a Hobby Lobby you also need to check their website for 40% off coupons, which they have been posting every other week. Target stores sometimes carry model rocketry items, and many other stores stock these supplies for the summer season.
The model rockets in most of these Starter Specials are the “RTF” kind, or Ready To Fly. They often have plastic nose cones and fins and are therefore a bit heavier, so they do not fly quite as high. However, as a “beginner” step they allow you to launch immediately and you do not have to take time to build. For a birthday party activity, these RTF kits are just about ideal. You could recover and re-launch a model rocket many times within one hour, even giving many different kids a chance to push the launch button.
Pay attention to what the package label says about the type of motors that are recommended for that specific kit because these are the motors you really need to stay with. If you need to purchase motors separately, you need to understand what the motor coding means. The general overall “power” of a model rocket motor is classified according to the amount of impulse a motor delivers, measured as the amount of thrust multiplied by the duration of that thrust. You may find motors that have slightly higher or lower impulse ratings within one range, but in general, B motors have twice as much impulse as A motors, C motors have twice as much impulse as B motors, and so on. The motors recommended for your rocket probably include several impulse classes, but you should probably stick to the smallest recommended motors (A, sometimes B for heavier model rockets) to keep the flight low and improve your chances of recovering the model rocket. After you have some experience, and see how your rocket behaves on the launch field you use, it may be OK to try larger motors. But if it is windy and your rocket drifts, it may be better to stay with smaller motors (and save those C motors for a larger launch field or a day with calm winds). I think it is better to get your rocket back and launch it again than to sail it out of sight and lose it. A lost rocket would bring your birthday party to a quick halt.
One other thing about selecting motors that is important is the last digit of the identifying motor code, the numeral after the dash. This number shows you what the ejection delay is, measured in seconds, if the motor is operating properly. This is the amount of time the rocket will coast between propellant burn-out and ejection charge activation. Your rocket’s recommended motors will probably call for a two, three, or four second delay (as in A8-3, or B6-4), and you should be careful to stick with those recommendations. If you use a longer delay the model rocket could reach peak altitude and start falling back down before the recovery system deploys; if you use a very long delay the model rocket could even hit the ground again before the ejection charge deploys the recovery system. Your re-usable model rocket could be ruined.
Where can you purchase model rocket motors? It is always good to support your local hobby shop with a few purchases, but if they do not carry much model rocketry inventory there are many other places to look. Many Walmart stores have model rocket kits and motors in their toy section (selection may be limited there). Hobby Lobby (and some Michaels stores) usually carry a good assortment of model rocket motors. If there is absolutely nothing available near you, some good mail-order sources are AC Supply at http://www.acsupplyco.com/home.htm, and Hobbylinc at http://www.hobbylinc.com/prods/tc_3.htm.
After you get familiar with the RTF model rockets you may want to move on to designs that require a few assembly steps. These are labeled “Skill Level 1” by Estes, and other manufacturers have similar designations. Some good beginner kits from Estes are the Big Bertha, Baby Bertha, Chrome Domes, Alpha, Der Red Max, and Patriot M-104. These are all large designs that stay (relatively) low and slow and are easy to recover. (You may want to pick up one of these and build it before the birthday party, to have a second model rocket that you can be preparing while the first one launches.) Other good Estes beginner kits include smaller rockets like the Viking and Wizard, but these are also relatively “hot” performers and are easier to lose. I would recommend that you avoid the Estes Swift and Quark, not because they are difficult to build, but because they are so small and fast---and nearly impossible to see in flight. You can view the 2008 Estes product catalog at http://www.estesrockets.com/assets/publications/2008estescatalog.pdf.
You also need to check out the newer model rocketry companies and their products. Quest is a growing company that sells motors and kits, and you may see some of their products on store shelves. Fliskits is another new company that sells motors and kits, including some model rockets that are cleverly designed just for beginners. For good beginner kits, check out the Fliskits Triskelion (fins designed to be easily aligned and assembled on a flat tabletop), Thing-a-ma-jig, and Whatchamacallit (with interlocking fin roots). You can find more information on Fliskits products at http://www.fliskits.com/. There are many more new model rocket companies, too many to list here!
You can search for local clubs on the NAR website (National Association of Rocketry) at http://www.nar.org/; they will be happy to help you with questions and advice. If you need more help you can join (for free) websites like The Rocketry Forum at http://www.rocketryforum.com/ or Ye Olde Rocket Forum at http://www.oldrocketforum.com/. There are lots of folks there with lots of experience that are happy to help with any rocketry question you might have.
Building model rockets with your children is an excellent way to encourage basic skills like reading and following kit instructions, understanding the strength and fragility characteristics of light weight materials, and building and finishing actual model kits. It’s a whole lot more fun than just reading about something or playing a computer game. Rocketry can lead to many more advanced aspects of science, math, and computer skills, if your child gets deeply interested. Advanced rocketry involves physics, aerodynamics, trigonometry (if you do altitude tracking), computer-based analysis and detailed simulation, and many others. You can even learn a touch of subjects like meteorology and electronics. And model rocketry is an excellent way to spend time with your children, encourage them to try new things, and be there to help out when they need it.
That may be more than you needed for a birthday party but I didn't want to miss the chance to encourage you to stay with this hobby. I hope this information is helpful, and that the birthday party launch session gives you the “bug” to continue! Let us hear from you again, after you get started and have more questions!
