OpenRocket not recognizing intermediate stage after export from RockSim.


Well-Known Member
Oct 29, 2018
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Hi everyone! Long-time lurker, first-time poster. I'm intentionally reposting this here and deleting the old thread, because on reflection it doesn't quite fit in "Rocketry Electronics and Software." No replies over there to miss, either.

I'm exploring high-altitude darts, and conversations with a friend of mine with a large amount of HPR experience has led to some design exchanges. Unfortunately, we both use different sim software - he uses RockSim, and I use OpenRocket.

This has led to what i think is a compatibility issue or just plain bug. When I try to simulate the vehicle that he sent me in OR, I wind up lowballing the altitude by missing the intermediate stage (between the powered-dart and the booster). I've been puzzling over it for a few hours, and I appear to have the same issue with RAS, so I suspect that something has gone wrong when converting the .rkt file to a .ork and back again.

Has anyone else had this issue? I know it's an open issue on OR's GitHub:, but I haven't been able to find an adequate solution, and other forum postings are too open-ended to be of much use. It seems like it might be fixed in the next release, though.

I've attached the OR file in question. Don't mind the slight roughness around the edges (though feedback is appreciated), this interrupted a work in progress.


  • SpaceDartv1.ork
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