I S S U E 198 - December 04, 2007 - Basics of Dynamic Flight Analysis Part 6 - Optimizing For Altitude

Oct 12, 2026

Issue 198 (December 04, 2007) of the Apogee Rockets newsletter explains how to design and refine a model rocket using Dynamic Flight Analysis, focusing on optimizing performance for altitude across varying wind conditions. The article describes a workflow in RockSim: defining the mission, checking static stability, then reducing drag by minimizing unnecessary components and fine-tuning configuration. It also answers a launch-site latitude question and includes an inside Q&A and Rocket design tips plus a December promotional offer.

LanguageEnglish

CategoryPresentations

FormatPDF

Pages10

Reading Time4 min

AccessFree to download

Basics of Dynamic Flight Analysis Part 6

Optimizing For Altitude

Step 1: Define the mission

Step 4: Check static stability

Step 5: Reduce drag coefficient

Question & Answer

I S S U E 1 9 8 - D e c e m b e r 0 4 , 2 0 0 7 | Basics of Dynamic Flight Analysis Part 6
Optimizing For Altitude
| | | | --- | --- | --- | | | Merry Chistmas From The Staff At Apogee Components | | | | | | | | |
INSIDE:
• Basics of Dynamic Flight Analysis
Optomizing For Altitude | | • Question & Answer
Why does RockSim ask you for the latitude of the launch site? | | | 3355 Fillmore Ridge Heights Colorado Springs, Colorado 80907-9024 USA [www.ApogeeRockets.com](www.ApogeeRockets.com) e-mail: [orders@ApogeeRockets.com](orders@ApogeeRockets.com) [Phone: 719-535-9335 fax: 719-534-9050](Phone: 719-535-9335 fax: 719-534-9050) I S S U E 1 9 8 - D e c e m b e r 0 4 , 2 0 0 7 Basics of Dynamic Flight Analysis Part 6 Optimizing For Altitude By Tim Van Milligan The purpose of these articles on Dynamic Flight Analysis is to learn how to adjust those parameters of a rocket's design that affect the way it behaves in flight. Of particular interest is how a rocket will react to a disturbance, such as wind. Once we know the important parameters, we can optimize the design. At this point, we've discussed all the parameters that are used to determine the dynamic characteristics of the rocket. We'll now outline a procedure for designing a model rocket. More than that, the overall objective is to design a rocket that will achieve the highest possible altitude over a wide range of wind conditions. We will use the RockSim software, because it is the perfect tool for this design process. If you don't have RockSim, you can download a 30-day trial edition at: [http://www.ApogeeRockets.com/](http://www.ApogeeRockets.com/) rocksim.asp Step 1: Define as nearly as possible the mission of the proposed rocket. Mission examples might be: • Altitude Competition • Payload carrying (egg or NAR standard 1-ounce payload) . What is the proposed capacity that it should be able to loft? • Does it need to be staged? • Will it use a cluster of motors? • What recovery system should be used? The purpose of these questions is to define the overall size of the rocket. We need to know what size (diameter) of tube we need to find. One important question you might want to ask yourself as you enter the components into the software is"can I actually get this part?" Many young rocket designers will design an awesome rocket in RockSim and then find out that they've created many custom sized parts that they can't buy from their favorite vendor (note: I hope your favorite vendor is Apogee Components, right?) . The nose cone is usually the one piece that is hardest to find if it is a custom size and shape. The point of this is that your design may be constrained by the parts that you can afford to buy. It is better to find this out now. Continued on page 3 About this Newsletter You can subscribe to receive this e-zine FREE at the Apogee Components web site ([www.ApogeeRockets.com](www.ApogeeRockets.com)), or by sending an e-mail to: [ezine@apogeerockets.com](ezine@apogeerockets.com) with“SUBSCRIBE” as the subject line of the message. Newsletter Staff Writers: Tim Van Milligan Layout / Cover Artist: Dave Curtis Proofreader: Michelle Mason A P O G E E R O C K E T S I S S U E 1 9 8 - D e c e m b e r 0 4 , 2 0 0 7 Continued from page 2 When inputting the fins, just use the default fins generated by RockSim for now. You'll come back later and resize and locate them to the best position on the rocket. Step 4: Check the static stability of the rocket so far. If the rocket is not stable, start by making the length a bit longer. DON'T add nose weight. That is a technique of the lazy. You're not lazy, are you? If the static stability margin is greater than 2.0, the rocket should be redesigned.* *The exception is super-roc style rockets. These are super-long rockets for a specific NAR contest. While a static stability margin larger than 2.0 is fine for most rockets, it will be harder

FAQs

What is the overall goal of the Dynamic Flight Analysis articles in this issue?

The goal is to adjust rocket design parameters that affect flight behavior and then optimize the design so it can achieve the highest possible altitude across a range of wind conditions.

Why does the newsletter suggest checking static stability during the design process?

It advises checking static stability so far and redesigning if the rocket is not stable. For most rockets, it discusses targeting appropriate static stability margin values for predictable behavior in breezy conditions.

How does the article recommend reducing drag to improve high-altitude performance?

It recommends reducing the drag coefficient by lowering drag sources, such as using only three fins instead of four or more, and removing the launch lug/rail buttons. It also notes that adding items like a boattail or reducer transition requires rechecking static stability.

Oct 12, 2026

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