OpenRocket 24.12 (2025-07-27)

These release notes cover the entire 24.12 release. Changes since 24.12.RC.01 are listed at the end. Notable features and fixes shown in bold.

RELEASE HIGHLIGHTS

Enhanced Simulation tab UI: This is the beginning of a multi-release effort to make it easier to manage simulations and interpret their results. Please let us know what you think so far.
Multi-level wind input: Configure different wind settings at different altitudes (in the simulation configuration dialog).
New Component Analysis Parameter Sweep Tool: Plot and export Component Analysis parameter sweeps in the new Component Analysis Plot/Export tab. For instance, you can plot the rocket CD as a function of Mach number.
SVG Fin Export: Export fin shapes directly to SVG for laser cutting or importing into CAD tools.
Window Ghosting Eliminated on Windows OS (!)
Extensive Improvements to error handling: There should be far fewer instances of ORK files encountering errors or exceptions while loading.
Expanded Platform Support: We now offer installers for x86_64 and Arm64 on Windows, Mac, and Linux.
Project documentation moved to Sphinx: See it at https://openrocket.readthedocs.io/.

Simulation

Overhauled Sim table GUI (fixes #2456)
Multi-level Wind Feature
Enter wind speed and direction at arbitrary set of altitudes for simulation (fixes #922, #2060, #2558)
CSV Wind Data Import: Import detailed wind profiles directly from CSV files.
Add "Wind Direction" flight data type
Plotting
Organize axis plot types selector into categories and add search function (fixes #2338)
Increase size of legend color patches for improved color visibility (fixes #2836)
Add air density as plottable variable (fixes #2462)
Show stage name in sim plot tooltips (fixes #2521)
Keep edit sim dialog open after plotting/exporting (fixes #2531)
Add Flight Warning events to plots
Warnings
Standardize Warning format (fixes #2669)
Add SIM_ABORT flight event type, instead of throwing exceptions
Improve how warnings are saved to and reloaded from ORK file (fixes #2694)
Don't warn about large angle of attack when we start to tumble
Don't set open airframe warning on booster stages if either they're about to deploy a recovery device or they're unstable (and improve wording)
Clarify "Open airframe" warnings when due to separated booster stage
Don't generate spurious warning when using a single tube fin (fixes #2663)
Other
Add "Altitude above Sea Level" as new flight data type
Include side boosters in thrust calculation (fixes #2639)
Allow for configurable maximum simulation time
Sync wind speed, deviation, and turbulence widgets together in sim settings (fixes #2388)
Add South/West units for latitude and longitude of launch site (fixes #2178)
Abort sim when recovery deployment occurs under thrust
Allow sustainer to tumble before apogee; if under thrust, abort sim
Fire outdated sim on stage rename (fixes #2532)
Added "aborted" status mark to simulations
Don't show vertical acceleration as negative before liftoff

Motor Configurations

Separate motor nominal vs. actual diameter (fixes #2569): This allows Loki 76mm motors to pass the 75mm motor filter.
Add 6mm (MicroMaxx) motor diameter to filter table
Add "Save as default" option to motor config name (fixes #2537)

Multi-stage Rockets

Add stage separation options for deployable payloads and a deployable payload example (fixes #852, #2519): We had many requests for this from various competition participants.
Don't add motor delay time to upper stage motor ignition time (fixes #2450)

Calculations

Correctly calculate CG on zero-length components (fixes #2626)
Improve handling of very small fins (fixes #2633)
Include enabled stages in calculations even if parent stage is disabled (fixes #2657)
Correctly handle "auto" mass object size when parent component is filled (fixes #2660)
Fix CP calculation error with tail cones (fixes #2751)
Clamp compressibility factor to avoid singularity at Mach 1 (fixes #2543)

Component Analysis

Plot and export component analysis parameter sweeps (fixes #2525): See the new Plot/Export tab.
Highlight component selected in Component Analysis in the rocket figure display
Add per-instance Cd column to Component Analysis Dialog (fixes #2019)
Select components for plot/export
Fix export of Component Analysis data (fixes #2697)

Import/Export

Export fins to SVG file: See button at bottom of config window
Improve OBJ export using Delaunay triangulation (fixes #2444)
Correct conical nose cone/transition OBJ exporting (fixes #2609)
Add option to export only one instance of component to OBJ
Support booster export and import with Rocksim, other bug fixes (fixes #2437, #2377, #2435)
Correct launch rod length when exporting to RASAero
Correctly handle periods in file path when exporting (fixes #2701)

Materials

Add material groups with search: Check this out in any config window.
Add "document materials" that can be reused within a document (i.e. ORK file)
Easier to add custom materials
Set balsa as default fin material

Preset Library

Fix parachute length resizing when using preset parachute: Lots of folks reported this one.
Fix transition and nose cone component presets defaulting to a filled shape (fixes #2480 and #2614)
Correct diameter of Spherachutes to match Cd (fixes #2517)
Fix sorting problems in preset library (fixes #2576)

User Interface

Window Ghosting Eliminated on Windows OS: @SiboVG finally squashed this vexing problem (fixes #1667)
Change look-and-feel engine to FlatLaf for all UI themes: after plenty of tweaking we think it's looking pretty good
Add UI Customization: You can now tweak the UI to your liking. Added "UI Scale", "Font Size", and "Character Spacing". See the "UI" tab in app preferences.
Rotate 2D views by click-dragging (fixes #2093)
Show Flight Config in Design View: This should make it easier to get all necessary information when screenshotting just the rocket figure display (fixes #2735)
Improvements to Rotation Control in 2D Views: You can now lock the angle so you don't accidentally rotate it with a click-drag; you can also enter the desired angle directly
Allow components to be hidden from view (fixes #2485): Use the edit menu or contextual menu to show/hide selected components
Constrain angles in freeform fin editor (fixes #427): Hold down shift or control-shift while dragging a point.
Add hex color input field in appearance panel (fixes #2224)
Include number of assembly copies in motor count display (fixes #2725)
Better positioning of modal dialogs (fixes #2652)
Correctly track when files have changed (fixes #2679)
Allow 3 digits of precision in "shape" parameter (fixes #2409)
Fix Mass Object radial rotation in 3D view (fixes #2550)

Developer stuff

Move project documentation to Sphinx
Switched build system from Ant to Gradle
Added Arm64 support for Windows and Linux
Adopted Java Platform Module System
Renamed `net.sf.openrocket` package to `info.openrocket.core` and `info.openrocket.swing`.
Add compatibility with plugins using the old `net.sf.openrocket` package instead of the new `info.openrocket.core` and `info.openrocket.swing`. The old plugins are copied and migrated to the new package structure with a `-migrated` suffix. (fixes #2676)
Clean up the "CSV Save" example simulation extension (fixes #2696)
Improve core startup for using OR in external Java app
Add clone helper methods to WorldCoordinate, Quaternion, and SimulationStatus
Choose user-defined component preset locations (fixes #1081)
Suppress preset and motor loading at startup (fixes #1579)

Misc

Re-introduced motor ignition delay optimization to Rocket Optimization (fixes #2345)
Support more and larger page sizes for printing (fixes #2483)
Improve manufacturer search in Component preset library (fixes #2479)
Fix shoulder scaling (fixes #2463)
Fix exception when changing the opacity setting in the appearance panel (fixes #2644)
Improvements to the software updater (fixes #2648)
Update "modified data" file metadata when saving
Add additional file properties (fixes #2664)
Honor Cd override when reading from a file (fixes #2745)
Add Piotr Tendera Rocket Motors (TSP) and Raketenmodelbau Klima (Klima) motor manufacturers to motor database
Enhancements and fixes to motor length and diameter filters

Notable Changes since 24.12.RC.01

Multi-level winds feature
Correct wind direction visualization
Remove 10 m/s max wind speed and 11 km altitude limit for wind levels (fixes #2767)
Allow for comments (starting with "#") and blank lines in multi-level wind CSV import
Major improvements to error handling (fixes to #2777, #2785, #2800, #2804)
Miscellaneous
Reduce size of simulation edit and Component Analysis dialogs for low-res screens
Make lateral angle and lateral orientation use north 0 (fixes #2811)
Example design updates: Rename TARC example to ARC, rurn example sims without errors
Include super-parent angles in instance rotation to ensure correct display in rocket figure display (fixes #2776)
Save latitude and longitude in degrees
Save and restore launchintowind element in ORK file (fixes #2802)
Developer features
Improve core startup for using OR in external apps
Add clone helper methods to WorldCoordinate, Quaternion, and SimulationStatus

...and countless additional fixes and tweaks.