The RASAero II Software is FREE!
To get the widest distribution of this software throughout the model rocket, high power rocket, amateur rocket, and alt.space/New Space communities, the RASAero II software is FREE! Download the RASAero II software by clicking on the link below.
New RASAero II software users:
After downloading the software, unzip the zip file, and run RASAero II Setup Version 1.0.2.0 to install the software.
If there is no error message, continue with the installation of the software, and complete the installation of the software.
If the following error message is displayed:
Click "No", and Exit the RASAero II Setup Program. Google "Enable .net 3.5", and follow the directions on enabling the .NET Framework version 3.5 on your computer.
Note that you may not need to Install .net 3.5, it may already be on your computer. You may only need to ENABLE .net 3.5. Scroll down in the instructions and find and try “Enable .net 3.5” before you try to “Install .net 3.5”.
Then re-run RASAero II Setup Version 1.0.2.0 to install the software.
When there are problems installing or running the RASAero II software, the solution is almost always “Enable .net 3.5”.
Current RASAero II software users, upgrading to RASAero II Version 1.0.2.0:
After downloading the software, unzip the zip file, and run RASAero II Setup Version 1.0.2.0 to install the software.
There is no need to uninstall any previous versions of the RASAero II software, just run RASAero II Setup Version 1.0.2.0 to install the new version of the software.
Your CDX1 rocket files can remain in the /My Documents/RASAero II directory.
If you have edited the rasp.eng motor data file to add new motors, rename the old file or save the old file in a separate directory. After installing the RASAero II Version 1.0.2.0 software add your new motors to the rasp.eng file which is located in the /My Documents/RASAero II directory.
The RASAero II Users Manual has been updated for the RASAero II Version 1.0.2.0 software. The RASAero II Users Manual is not included in the software download, and is downloaded separately from the RASAero II Users Manual page.
Note: The RASAero II software is compatible with Windows 11, Windows 10, Windows 8, Windows 7, Windows Vista, and Windows XP.
RASAero II release history:
Version 1.0.2.0 – Release Date May 22, 2019
Corrected errors in the nose cone wave drag models for LV-Haack, parabolic, and elliptical nose cones. There were no errors in the nose cone wave drag models for tangent ogive, Von Karman ogive, conical, and power law nose cones. Nose cone wave drag occurs at transonic, supersonic, and hypersonic Mach numbers.
Added the ability to enter nested upper stages; where the upper stage motor extends beyond the bottom of the upper stage and slides into the front of the booster stage.
Added new protuberance drag models (for missile raceways, camera shrouds, fin brackets, etc.); streamlined no base drag, streamlined with base drag, and inclined flat plate.
Combined protuberance drags; rail guide, launch lug, launch shoe, streamlined no base drag, streamlined with base drag, inclined flat plate; into one combined protuberance drag coefficient (CD) output.
Added option to the existing capability to export tabular output data from the Flight Simulation to an Excel (.CSV) output file, where rather than having the data exported to the file in increments of every 0.01 sec, the user can select every 0.01 sec, 0.10 sec, 0.50 sec, or 1.0 sec. (The Flight Simulation is still run with a time step of 0.01 sec, the data is just exported in larger time steps.)
Note that the Aerodynamic Plots also has the existing capability to export aerodynamic tabular output data to an Excel (.CSV) output file.
Corrected error in the first motion on the launch rail when the initial thrust was lower than weight. Rocket did not slide backwards on the rail, but negative acceleration was built up which had to be unwound into positive acceleration before the rocket would begin to move up the rail.
Made further improvements in the extensions to the power-on base drag model for very large nozzle exit diameters at supersonic and hypersonic Mach numbers, with the nozzle exit area filling a large portion of the rocket base area, for more accurate power-on CD predictions for first and second stages of satellite launch vehicles. No change in the power-on CD for most model, high power, and amateur rockets.
Made mods to the Rogers Modified Barrowman Method nose cone subsonic potential CNAlpha and Center of Pressure (CP) equations for increased accuracy. In the Rogers Modified Barrowman Method the Nose Cone and the body tube which follows the nose cone are treated aerodynamically as a single unit for subsonic potential CNAlpha and CP.
Made mods to the Rogers Modified Barrowman Method expansion section subsonic potential CNAlpha for increased accuracy. No mods were made to the Rogers Modified Barrowman Method expansion section subsonic potential CP.
Corrected error in the Barrowman Method subsonic CP for LV-Haack nose cones.
For rounded and square airfoils with All Turbulent Flow corrected errors in the fin supersonic and hypersonic friction drag.
Modified line-up of print columns in subsonic, transonic, and supersonic and hypersonic print outputs.
Version 1.0.1.0 – Release Date August 5, 2016
Changed the recommended stability margin for subsonic Mach numbers to a stability margin of 1.0 calibers, kept the recommended stability margin for transonic and supersonic Mach numbers at 2.0 calibers, for the marginal stability warning message.
Added extension to power-on base drag model for very large nozzle exit diameters at supersonic and hypersonic Mach numbers, with the nozzle exit area filling a large portion of the rocket base area, for more accurate power-on drag coefficient (CD) predictions for first and second stages of orbital launch vehicles.
Added stability margin (calibers) to the Flight Simulation plots.
Added additional outputs to the Flight Simulation Excel (.CSV) output file.
Version 1.0.0.0 – Release Date September 12, 2015
Initial Release - New and improved models and capabilities compared to the RASAero software:
New and improved supersonic Center of Pressure (CP) models. Rocket supersonic CP typically moved forward approximately 1 caliber compared to previous RASAero models. For supersonic stability should run RASAero II software rather than RASAero software.
New multi-stage capability for aerodynamic predictions and for flight simulations. RASAero II software can run rockets with up to 3 stages.
User-specified booster separation delay and upper stage ignition delay for delayed staging, or coast before ignition of upper stage.
Ability to import RockSim .rkt rocket files directly into RASAero II.
New and improved dynamic stability models.
New and improved transonic CD models.
New and improved supersonic boattail wave drag and base drag models for increased altitude prediction accuracy for rockets with boattails.
For very steep or very short boattails, new flight data-based boattail wave drag and base drag models which eliminate unrealistically high altitude predictions for very steep or very short boattails.
Added power law, LV-Haack, parabolic and elliptical nose cones, including subsonic, supersonic, and hypersonic CD, Cnalpha and CP models for the new nose cones.
Added the capability for 5, 6, 7 and 8 fins, to the existing 3 and 4 fins.
Added improved viscous crossflow models to the Rogers Modified Barrowman Method and the supersonic body CP methods for improved predictions for the forward movement of the rocket CP with angle of attack.
New and improved Rogers Modified Barrowman Method subsonic CP models at low angle of attack.
Added improved, increased accuracy launch shoe subsonic, supersonic, and hypersonic CD models.
Added new and improved square airfoil leading edge wave drag model.
Made corrections to square airfoil and rounded airfoil friction drag models for all turbulent Made corrections to square airfoil and rounded airfoil friction drag models for all turbulent flow.
Rocket reference area changed from base area of the nose cone to the maximum cross-sectional area of the rocket body.
Updated the rasp.eng motor database file with new motor data for TRA/NAR/CAR certified motors.
RASAero release history:
Version 1.0.2.0 - Release Date March 15, 2011
Modifications made for full compatibility with 32-bit and 64-bit versions of Windows 7. Some problems were seen on the prior release version with 64-bit versions of Windows 7.
Version 1.0.1.0 - Release Date January 7, 2009
Updated the rasp.eng motor database file with new motor data for TRA/NAR/CAR certified motors.
Made corrections to fix error where fin leading edge radius was not being saved in the ALX1 file. When entered on the input screen the correct fin leading edge radius would be used. But upon saving the ALX1 file, the fin leading edge radius would be reset to zero, and would have a value of zero for future runs, unless manually entered again every time the rocket was run.
Corrected error where the View Rocket scale rocket drawing would always display the Barrowman Method center of pressure (CP), even when the Rogers Modified Barrowman CP Method was selected. The software Aero Plots, the Aero Plots tabular outputs, and the file outputs were correct, the only error was that the View Rocket drawing would always show the CP symbol in the Barrowman Method CP location.
Made corrections to fix error where on very high altitude flights (above 200,000 ft) extremely low Reynolds numbers would cause unrealistically high drag coefficients. Correction added a low Reynolds number cut-off to avoid very low Reynolds numbers (under 10,000) at high altitude.
Made correction to fix error on View Rocket scale rocket drawing where for some rockets (typically rockets with a short boattail on a fin canister) the base of the rocket would run off the edge of the View Rocket drawing.
On the Flight Simulation changed Engine Selection to Motor Selection.
On the Aero Plots tabular output added units (deg) after Alpha and (in) after CP.
Changed Run Test input screen and file saving options for Windows 7 64-bit compatibility.
Updated Run Test section of Users Manual. Added section on exporting flight simulation tabular output to Excel file to Users Manual. Added updated Comparisons with Altitude Data Table to Users Manual.
Made corrections to solve problems that arose when installed and run on computers using European regional settings.
Version 1.0.0.0 - Release Date September 11, 2008
Made corrections to fix errors in equivalent sand roughness (surface finish) skin friction coefficient calculations for very rough surface finish rockets. Errors caused very rough surface finish rockets to fly higher than same rocket with a smoother (reduced roughness) surface finish.
Made corrections to check that the fin can outer diameter is larger than the body tube diameter.
Corrected two misspelled words on rocket input descriptions.
The E-mail address used to send an e-mail from the RASAero software support page has been corrected. (E-mail had to be forwarded from the old e-mail address.)
Initial Release version.