Deveopment of a de-orbiting mechanism for a 3-unit satellite

Two cost effective mechanical de-orbiting systems based on aerodynamic drag enhancement principle are developed for a 3-Unit (3U) satellite, TURKSAT-3USAT, in Low Earth Orbit (LEO). The first de-orbiting mechanism of interest uses spiral springs as energy producing mechanism for mechanical deployment as well as thin membranes which are planned to provide orbit decay as aero-brake structures. Membrane storage is provided by a storing unit with storing cylinders when the system is de-active while the deployment of the system till the end of mission life is prevented by a lock mechanism. The second system employs a simpler working principle by just involving a spiral spring mechanism. The deployment is provided through the solar panel spaces by the direct contact between springs and the deployment material. The sizing of deployable structure in both designs depends on the neccssary drag area for de-orbiting while the designs are even expected to be reliable with low mass and small volume requirements. The required drag area is calculated through maximum de-orbiting time of the satellite, which is determined as 25 years by considering the maximum orbital life time suggestion of United Nations Inter-Agency Space Debris Coordination Committee (IADC). De-orbiting time values of each design are calculated in Satellite Tool Kit (STK) by considering J4 perturbation propagator and NRLMSISE 2000 as a high-fidelity atmospheric model, and finally checked whether they satisfy the specified maximum life time criterion. The final design is selected by considering reliability criteria, and is planning to be manufactured and tested in Space Systems Design and Testing Laboratory (SSDTL) of Istanbul Technical University (ITU).