There are three applications as sub-projects on the Constellationplatform.
Ascend trajectory simulation and optimizer for space-launcher systems and space-crafts. TrackJack's origin is part of a diploma thesis in Aerospace Engineering at the University of Applied Sciences Bremen.
Contact Andreas Hornig for details.
Trajectory Optimization 101
In the current version TrackJack is able to find an ascent trajectory (flight path) for a launcher rocket into the target orbit.
This is done according to the equations of motion on a 2D plane. The finder algorithm changes the thrust vector, that controlls the steered direction, and finds the best thrust vector angle at any discrete time-step. This is repeated for each time-step until all thrust vector angles are found for the complete flight-time and the controll-function is formed.
The found control-function leads to a continous trajectory between the existing boundary values for start and target conditions and is done in respect to gravity turn condition and aerodynamic drag. This is important to minimize the lost thrust for steering that can't be used for direct translative acceleration, because gravity will bend the rocket's trajectory. By only fulfilling gravity turn condition it would bend the trajectory to tangent into deeper atmosperic regions, so the atmosphere will lead to a high aerodynamic drag that will decellerate the rocket. So the finder algorithm will find a trajectory that is a compromise between these and even more conditions.
Scientific Goal and Future Features
TrackJack's goal is to solve problems during ascent, interplanetary and re-entry trajectories.
The first step will be to validate data analysed for the diploma thesis this app derived from to be sure, that the BOINC-app will lead to correct results.
The next step will be to add new features to TrackJack that will allow new trajectory forms like interplanetary missions and re-entry paths. One of the first added features is thrust-profile finder for the sounding rocket that is designed by DGLR-Group HyEnD - Hybrid Engine Development. The maximum altitude of the sounding rocket is optimized by combinatorical variegating the thrust level at discrete gridpoints near the speed of sound (Ma = 1).
TrackJack is a single-core application using Java JRE (Java Runtime Environment) and 7-Zip compression for app and workunits.