OpenRocket is an application for virtually building and launching model rockets. This software was developed by Sampo Niskanen, who was a student at the Helsinki University of Technology when he developed OpenRocket as the focus of his graduate studies on open source software. OpenRocket is fun and easy to use. The online guide, Getting Started with OpenRocket. advises basing your rocket designs on existing products, so I chose to virtually create and launch an Estes Hi-Flier (kit number 2178) as shown in the image below.
OpenRocket launches with a pop-up window asking the user to provide rudimentary information about the rocket he or she plans to design (design name, designer and a field for comments). If desired, this window can be readily closed so that the user can begin working with the application.
The OpenRocket interface is very straightforward. A simple menu bar is at the top of the window, allowing users to perform common tasks (Open, Save, Undo, etc.). Below this are two tabs, Rocket design and Flight simulation. The Rocket design tab employs a kind of switchboard interface that allows users to select which model rocket components they would like to add to their build. The only three options available at start up are Nose cone, Body tube and Transition (a coupler that is tapered at one end). To the left of this switchboard is a window displaying a text-based tree-structure outline of your rocket. The lower half of the screen is the canvas upon which your design appears. The default is Side view, but users can toggle between this are Rear view. This canvas is flanked on top and to the left by rulers measuring centimeters. At the top of the OpenRocket window is a simple menu.
When a new component is added to your rocket, the Component configuration window opens providing information about the component’s shape, composition and mass, as well as offering options to modify the component. Additional tabs are available for configuring such categories as mass override, figure (illustration) style and a field for notes about the model. This feature can also be accessed by clicking on a component and choosing Edit from the switchboard menu just to the right of the outline window. Components in the outline area can be expanded to reveal sub-components or collapsed to hide them. Components can also be moved here by clicking on a component and dragging it to a desired location in the tree-structure. Furthermore, components can be modified using the switchboard immediately to the right of this window. Two really neat features included under the Analyze menu include Component analysis and Rocket optimization. These allow you to tweak your rocket’s performance.
Once you’ve added an engine, the fun begins, as the guide Getting Started with OpenRocket states, as you’re ready to enter into the simulation portion of the application. OpenRocket is well integrated with the model rocket industry in regards to measurements and sizes of various components. For example, when you are ready to select a motor, if you have properly configured your engine mount, only motors that will fit the engine mount will be listed. Once you have selected your engine (or engines), we’re ready to run a simulation. Click on the Flight simulations tab. The Flight simulations window has five buttons at the top of the screen allowing users to create, run and modify simulations. Below this is a pane in which are listed user-created simulations. Below this is the canvas showing the user’s rocket.
Clicking on New simulation opens the Edit simulation window. Under the Launch conditions tab, you can customize the simulation in terms of engine configuration, wind speed, atmospheric conditions and other launch conditions. When the launch is configured as desired, click the Run simulation button. A window with simulation information will flash on the screen. Click on the Plot/export button and this will open the Edit Simulation window. In this window, users can adjust various criteria relating to the simulation, such as launch conditions, simulation options and what types of data will be plotted. Once this information has been set, simply click the Plot flight button in the lower right corner and a window presenting a graphic representation of the rocket’s flight will open. What’s really fun is to tweak various rocket components and launch conditions to see how they affect a rocket’s trajectory.
So, what are the benefits to using OpenRocket? It provides a wonderful opportunity to build and test model rockets prior to launch. What this means to model rocket enthusiasts is that they will have a better opportunity to determine their rockets’ trajectories and, therefore, have a better chance at recovery. Plus, it’s a fun way to experiment with model rockets. Isn’t that really what it’s all about?
OpenRocket is available for Linux, Apple MacOS, Microsoft Windows and Android.
Niskanen, S. (2009). Development of an open source model rocket simulation software. Helsinki: Helsinki University of Technology. Retrieved from: http://openrocket.sourceforge.net/thesis.pdf
Pummill, J. et al. (n.d.). Getting started with OpenRocket. TRF Community. Retrieved from: http://comp.uark.edu/~jpummil/OR-Start.pdf