In current CubeSat observation satellites, the main design constraint is the available space. Standards dictating the unit dimensions of the payload severely restrict the maximum aperture and focal length of the optical instrument. In this paper, the authors present the results of work to produce a novel DeploScope optical system for a CubeSat-type observation satellite with a segmented aperture of the primary mirror deployed in space. The telescope is designed for Earth observation and is expected to find its application in the military, precision agriculture or environmental disaster prevention. The work includes a detailed analysis of the segment aperture effect on image repeatability for different numbers of main mirror segments. Based on it, the optimal configuration of the optical model of the telescope with an aperture of 188.5 mm and a focal length of 1100 mm was selected. Based on this analysis, a so-called laboratory version of the telescope was built, providing the possibility of free correction of each segment of the primary mirror while maintaining a solid stable base for other components of the module. Imaging tests were carried out on the laboratory version of the instrument and the system was optimized for a version suitable for implementation in the payload structure of the microsatellite.
Jedna z metod określania orientacji przestrzennej małych satelitów orbitujących wokół Ziemi polega na jej odtwarzaniu poprzez porównywanie pomiarów pola magnetycznego oraz kierunku położenia słońca z odpowiednimi modelami. By było możliwe wykonywanie tego zadania w czasie rzeczywistym, modele takie muszą być wystarczająco dokładne, a jednocześnie nie mogą być zbyt kosztowne obliczeniowo. Niniejszy artykuł przedstawia sposób tworzenia dedykowanego modelu pola magnetycznego Ziemi, powstały przez redukcję bardziej złożonego jego odwzorowania. Rozwiązanie to zapewnia możliwość elastycznego dostosowania wymaganej dokładności przy jednoczesnej redukcji kosztu obliczeniowego.
EN
One of the methods of determining orientation of a small satellite orbiting Earth is based on recreating spacecraft's orientation from comparison of measured magnetic field vector and Sun position with their respective models. To achieve this in real-time regime it is necessary that those models have sufficient precision and are relatively easy to compute. In this paper a methodology of creating Earth magnetic field model will be proposed. It will be shown that by reducing more complex model and optimizing its parameters it is possible to achieve adjustable precision with simultaneous reduction of computational cost.
Cube Satellites are miniaturized satellites used for space research with a mass of not more than 1.33 kg per unit. They are widely used in space applications because of its low cost of manufacturing and flexibility of applications. Since, they use commercial off-the-shelf components, thermal consideration of internal components of 1-unit cube satellites becomes a necessity. In this paper, transient thermal analysis of a 1-unit cube satellite is conducted to analyze its behavior during the first 29 seconds of orbit insertion from the launch vehicle. Transient thermal analysis yielded a temperature range that exceeded the optimum limit. As a result, to reduce heat dissipation, two main types of thermal management systems for satellites: active control and passive control systems are included. To maintain critical components at their operating temperature, a passive thermal control is implemented. Thermal strap and multi-layer insulation are used to analyze internal components of 1-unit cube satellite. Using graphite fiber thermal strap and aerogel multi-layer insulation for internal components, the 1-unit modular cube satellite is found to be more suitable under low earth orbit conditions.
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The current work focuses on vibration and modal analysis of KufaSat structure using ANSYS 16 program. Three types of Aluminum alloys (5052-H32, 6061-T6 and 7075-T6) were selected for investigation of the structure under design loads. Finite element analysis (FEA) in design static load of 51 g was performed. The natural frequencies for five modes were estimated using modal analysis. In order to ensure that KufaSat could withstand with various conditions during launch, the Margin of safety was calculated. The results of deformation and Von Mises stress for linear buckling analysis were also performed. The comparison of data was done to select the optimum material for KufaSat structures.
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Since the advent of the CubeSat nanosatellite standard it has been embraced by many universities as an affordable means of conducting space science, with the backbone of any such mission being the supply of electrical power to the spacecraft’s payloads. This paper details the design of a photovoltaic-battery based power supply utilising peak power trackers for solar array regulation and battery charging. Uniquely, the peak power tracking is executed by an active search algorithm, Perturb & Observe, in both analogue and digital form as a measure of redundancy.
PL
W artykule opisano projekt baterii fotowoltaicznych wykorzystujący układ śledzenia maksymalnej mocy do sterowania procesem wytwarzania energii i ładowania baterii. Wykorzystano algorytm Perturb & Observe.
One of the most critical systems of any satellite is the Electrical Power System (EPS) and without any available energy, the satellite would simply stop to function. Therefore, the presented research within this paper investigates the areas relating to the satellite EPS with the main focus towards the CubeSat platform. In this paper, an appropriate EPS architecture with the suitable control policy for CubeSat missions is proposed. The suggested control strategy combines two methods, the Maximum Power Point Tracking (MPPT) and the Battery Charge Regulation (BCR), in one power converter circuit, in order to extract the maximum power of the Photovoltaic (PV) system and regulate the battery voltage from overcharging. This proposed combined control technique is using a Fuzzy Logic Control (FLC) strategy serving two main purposes, the MPPT and BCR. Without an additional battery charger circuit and without switching technique between the two controllers, there are no switching losses and the efficiency of the charging characteristic can be increased by selecting this proposed combined FLC. By testing a space-based PV model with the proposed EPS architecture, some simulation results are compared to demonstrate the superiority of the proposed control strategy over the conventional strategies such as Perturb and Observe (P&O) and FLC with a Proportional Integral Derivative (PID) controller.
Artykuł przedstawia znaczenie stacji naziemnych w zapewnianiu skutecznej komunikacji z satelitami CubeSat, które stały się coraz bardziej powszechne w przestrzeni kosmicznej. Stacje naziemne pełnią kluczową rolę w ułatwianiu przesyłania danych, kontrolowania i monitorowania tych niewielkich satelitów, które często operują na niskich orbitach okołoziemskich. Artykuł podkreśla również znaczenie ciągłego rozwoju stacji naziemnych, aby sprostać dynamicznym potrzebom współczesnych misji kosmicznych wykorzystujących satelity Cube-Sat.
EN
The paper discusses the importance of ground stations in ensuring effective communication with Cube-Sat satellites, which have become increasingly common in space. Ground stations play a crucial role in facilitating data transmission, controlling, and monitoring these small satellites, which often operate in low Earth orbits. The article also emphasizes the significance of the continuous development of ground stations to meet the dynamic needs of contemporary CubeSat-based space missions.