Thorsten
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I'm happy to present the first version of LEO targeting, a C++ tool to analyze orbits and compute orbital maneuvering burn plans.
The tool does numerical solutions of trajectories in J3 gravity with an ellipsoid earth shape, finite duration burns both with given Delta v (PEG-7) or using PEG-4 targeting and constrained optimization (for instance it can do questions like 'What's the most propellant-efficient ignition time for a PEG-4 de-orbiting solution assuming I want a range of 3600 miles from entry interface to landing site from my current eccentric orbit?')
I believe this may not only be of use for my Flightgear Shuttle project but also for the Orbiter community.
To illustrate the things numerical orbital dynamics does - here's a test computing the stability analysis for a Molniya orbit where a 63.4 inclination is stable against the J2 perturbation and has a periodically varying argument of the periapsis whereas changing the inclination to 53.4 degrees gives rise to a drift of the parameter.
There's a manual provided with the code, and I'm in the process of adding tutorials for interesting problems to the website.
The software is licensed under the terms of the GPL 2+.
Download the source code from here
There is no executable provided (I'm working under Linux and can't compile for Windows) - anyone who wants to create a Windows binary is cordially invited to do so, and I'll be happy to host the file on my website. As far as I'm aware there's only standard C++ libs used, so it should compile fine cross-platform.
The tool is not extensively tested, I proceed according to the free software philosophy 'release early' in the hope that more eyes are better in bug-spotting, so feedback (and patches) are welcome.
I plan to develop this further to assist rendezvous computations as well, so there'll be more than just optimized insertion and de-orbit solutions.
The tool does numerical solutions of trajectories in J3 gravity with an ellipsoid earth shape, finite duration burns both with given Delta v (PEG-7) or using PEG-4 targeting and constrained optimization (for instance it can do questions like 'What's the most propellant-efficient ignition time for a PEG-4 de-orbiting solution assuming I want a range of 3600 miles from entry interface to landing site from my current eccentric orbit?')
I believe this may not only be of use for my Flightgear Shuttle project but also for the Orbiter community.
To illustrate the things numerical orbital dynamics does - here's a test computing the stability analysis for a Molniya orbit where a 63.4 inclination is stable against the J2 perturbation and has a periodically varying argument of the periapsis whereas changing the inclination to 53.4 degrees gives rise to a drift of the parameter.
There's a manual provided with the code, and I'm in the process of adding tutorials for interesting problems to the website.
The software is licensed under the terms of the GPL 2+.
Download the source code from here
There is no executable provided (I'm working under Linux and can't compile for Windows) - anyone who wants to create a Windows binary is cordially invited to do so, and I'll be happy to host the file on my website. As far as I'm aware there's only standard C++ libs used, so it should compile fine cross-platform.
The tool is not extensively tested, I proceed according to the free software philosophy 'release early' in the hope that more eyes are better in bug-spotting, so feedback (and patches) are welcome.
I plan to develop this further to assist rendezvous computations as well, so there'll be more than just optimized insertion and de-orbit solutions.