OpenRocket

Rocketry is a fascinating subject and anyone who grew up with toy soldiers would want to build a scale model and launch it. Building a model rocket that would actually fly involves countless calculations, trial and error runs and, as Krafft A. Ehricke said, you should always follow a simple rule in rocketry: always assume that it will explode. Before you start building anything, you should carefully design your rocket, to make sure that it won't take a nose dive into the ground when you launch it. OpenRocket can help you design rockets from scratch and it can make all the necessary calculations for you, based on the used components, materials, weight distribution and so on. It allows you to build your rocket step by step and make a wide range of configurations for individual components.

OpenRocket is a free and open source project, in which anyone can get involved. The application is based on Java, so you can run it on any operating system that supports this language. Besides that, you can run the application immediately, without going through an installation process.

Using the application's controls is not rocket science, but you would still need to understand a few thins about rockets, specifically how they behave in mid air or when they are launched. If you are familiar with these aspects, you should not have any difficulties designing a rocket. Instead of relying on a 3D environment and complex options that would slow you down, the main user interface has a simple and comfortable layout.

You can add components to your rocket by clicking their icons on the upper half of the interface. A sketch of your rocket is displayed on the lower half, so you can preview its design. When you add a component, a tabbed configurations window will show up, on which you can make all sorts of modification to the new component. Added components will appear in the preview area instantly and their shapes and sizes will change in real time, according to your modifications.

OpenRocket places all the components you need at your disposal. Besides the rocket's nose cone, transition section, body tube and fins, you can also add inner components, like tubes, couplers, bulkheads or engine blocks, as well as mass objects, shock cords or parachutes. You can also designate a component as the motor mount, which can be configured in various ways. Furthermore, the software allows you to choose from a vast range of predefined motor types, which come with all sorts of statistics.

The best part is that OpenRocket keeps track of all tedious details, like a component's weight, thickness, length, diameter and so on. You can find a wide range of specifications, on the rocket's sketch, such as mass, maximum acceleration and velocity, apogee, stability and others. These statistics are calculated automatically, according to how you modify the rocket's components. The application also displays the rocket's center of gravity and it will move it accordingly as you modify a component. Another clear advantage is the fact that OpenRocket allows you to prepare and run simulations, which could give you a general idea on how your rocket will fly, for how long and how high.