### Using the flywheel engines system in implementing the spacecraft solar orientation mode

**Published:**18.10.2022

**Authors:** Ignatov A.I., Ivanov G.A., Kolomiets E.S., Martynenkova E.V.

**Published in issue: **#10(130)/2022

**DOI: **10.18698/2308-6033-2022-10-2219

**Category:** Aviation and Rocket-Space Engineering | **Chapter:** Aircraft Dynamics, Ballistics, Motion Control

The study is devoted to maintaining the solar orientation mode of the gyrostat spacecraft in the low earth orbit through a long period. The device shape is close to a cylinder with two fixed solar panels installed along the cylinder longitudinal axis symmetrically relative to it. In the solar orientation mode, the normal to the device solar arrays plane is invariably directed towards the Sun and the longitudinal axis oscillates relative to the orbit plane. To implement the specified spacecraft motion mode, a system of four flywheel engines is used, which rotation axes are directed in parallel to the side edges of the quadrangular pyramid. Position of the pyramid side edges relative to the coordinate system rigidly connected to the device is determined by two angles, which are the parameters of the flywheel engine system. The law of the gyrostatic moment control is considered ensuring attenuation of the perturbed spacecraft motion in the vicinity of its solar orientation and limiting accumulation of its intrinsic kinetic moment of the flywheel engines by controlling the device rotation angle around the normal to the light-sensitive side of the solar arrays. It is demonstrated that selection of certain parameters of the flywheel engines coordinate system would assist in implementing the solar orientation mode without unloading the gyrostatic moment during the entire flight time. Results of numerical simulation of the complete system of the spacecraft motion equations in its solar orientation mode are presented taking into account the influence of gravitational and aerodynamic moments, which confirms correctness of the selected parameter values.

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