This paper presents the results of numerical modeling and vibration testing of a nanosatellite’s optical payload, aimed at assessing its mechanical stability under the mechanical impacts of launch. The purpose of the study is to compare finite element modeling (FEM) data with experimental testing to refine the computational model and improve the reliability of mechanical stability predictions. The methodology included an FEM analysis with an average damping coefficient, an adapter blank test, a resonance study with a low-level sinusoidal run, random vibration tests, and a sinusoidal pulse test. The FEM results showed an average yield margin of safety MoS = 2.5 with a minimum MoS = 1.8 in the primary mirror mount area. The adapter blank test confirmed the absence of natural resonances in the operating range. The resonance study revealed modes in the 300–1340 Hz range, with the most pronounced peaks in the secondary mirror bracket (520–600 Hz) and the electronics unit (1030–1100 Hz). A comparison of the root mean square (RMS) acceleration values between calculations and tests revealed discrepancies due to the heterogeneous nature of the damping. The values of ζ determined by the half-power method varied from 0.9% to 4.8%, which confirms the dependence of the damping properties on the frequency and localization of the modes. The obtained results confirmed the structural integrity of the payload, allowed for the localization of structural elements, and substantiated the need to consider actual damping coefficients in FEM models. The presented data can be used to optimize the design and improve mechanical stability during payload integration into the satellite platform.

The object of this study is the process of deorbiting the KazEOSat-1 spacecraft, which has completed its active service life in low Earth orbit. The main problem is the lack of an effective technique to deorbit KazEOSat-1, taking into account its technical characteristics, orbital parameters, and the need to minimize risks to the environment and other objects in orbit. As part of the work, a software model was built that takes into account the initial orbital parameters of the device, which are essential for planning and performing deorbiting maneuvers. The model is designed to accurately calculate the descent trajectory, taking into account the laws of celestial mechanics and the influence of atmospheric conditions. The optimal deorbiting strategy was selected based on an analysis of various methods for calculating orbital maneuvers aimed at reducing fuel consumption and minimizing environmental risks. This included a comparative analysis of existing approaches and the selection of the most suitable ones under the given mission parameters. The results of the simulation using precise modeling methods in the MATLAB software environment allowed us to determine the main deorbiting parameters, such as the altitude at which the maneuvers begin, the required velocity impulses, the total fuel consumption, and the expected time before entering the dense layers of the atmosphere. Based on the obtained data, practical recommendations were formulated for the KazEOSat-1 deorbit. The first stage, the active controlled deorbit, is carried out by operating the low-thrust engine and braking by the Earth’s atmosphere, allowing the spacecraft to descend from 758 km to 444 km in 2.5 days. The second stage, the passive uncontrolled deorbit, continues the descent to 103 km in 969 days, using only atmospheric braking. The third stage, the uncontrolled drop, begins after reaching 103 km and ends with a drop to the Earth in 834 seconds

This paper presents the design and numerical assessment of a compact short-wave infrared (SWIR) optical payload for a CubeSat nanosatellite platform. The proposed payload is intended to provide sequential imaging in selected SWIR bands using a revolver filter wheel while accommodating a long-focal-length optical system within a limited 3U volume. The optical layout is based on a modified Maksutov configuration with an effective focal length of approximately 550 mm and an aperture of 84 mm. The system is designed to achieve a ground sampling distance (GSD) of ≤15 m at an orbital altitude of 500–550 km. For sequential imaging in different regions of the SWIR range, filters with central wavelengths of 1.24, 1.6, 1.9, and 2.1 μm are used together with an additional broadband window. The optical performance was evaluated using spot diagrams and modulation transfer function (MTF) analysis for the selected spectral bands. A preliminary thermo-optical sensitivity assessment was also performed over the temperature range from −20 °C to +40 °C by considering temperature-induced changes in axial distances between optical elements and surface curvatures caused by material expansion. The results indicate that the MTF at the detector Nyquist frequency of 33 lp/mm remains above the selected threshold of 0.1 for the considered spectral bands and uniform temperature states. The proposed configuration demonstrates the feasibility of implementing a compact long-focal-length SWIR payload with filter-wheel-based band selection for CubeSat missions, while maintaining the required calculated image quality within the considered design-stage assumptions.