Thrust Curve Tool

Update: v1.06 (Nov. 1, 2006)

Click here to download

        Runs on Windows, Macintosh, and Linux

        New features:

1.       Improved curve fitting when using data smoothing.

2.       Inserts new info into ENG file comments.

3.       Locates ejection mark and calculates ejection delay.

(click on graphic for full sized view) .

Thrust Curve Tool was designed to analyze rocket motor thrust data and to produce standard ‘.eng’ files for use with flight simulators such as wRASP and Rocksim™. The program makes it easy to visualize the thrust curve, determine the motor’s specifications, plot the data, and produce an optimal ‘.eng’ file. It’s now possible to go from motor test firing to rocket simulation in just a few minutes!


This software tool is useful for both amateur/experimental rocket motor builders and model rocketeers. If you have a test stand and a data acquisition system, you may load the raw output data into Thrust Curve Tool in a variety of formats. It will compute the total impulse, peak thrust, average thrust, specific impulse, burn time, and standard NAR/TRA motor designation. You have the options of filtering the data and choosing the number of points for the “.eng” output while interactively generating a “best fit” compact thrust curve.


The “Auto Optimize” feature further automates the curve-fitting process. By selecting this option, the program finds the least number of points needed to reproduce the thrust curve shape while maintaining the original total impulse. In most cases, a simulation program will produce the same flight profile with this minimized ‘.eng’ file as it would with the raw data points. If you wish to override the results, Thrust Curve Tool lets you increase the number of points while automatically reshaping the optimized curve and adjusting the total impulse.


The program also reads in existing ‘.eng’ files. This feature is useful if you wish to visualize and plot a rocket motor’s thrust curve, or verify any manual modifications you may have made to an ‘eng’ file. For example, a delay at the beginning of the thrust curve is useful when simulating a cluster with air-started motors.


The interactive display allows you to resize the plot while automatically scaling and labeling the axes. A JPEG image of the graph may be saved to a file or copied to the clipboard and pasted into other programs.


PRICE: Free download !

An optional $10 shareware donation is requested.




Rocksim™ is a trademark of Apogee Components