We experimentally analyze collective dynamics of a population of 20 electronic Wien-bridge limit-cycle oscillators with a nonlinear phase-shifting unit in the global feedback loop. With an increase in the coupling strength we first observe formation and then destruction of a synchronous cluster, so that the dependence of the order parameter on the coupling strength is not monotonic. After destruction of the cluster the ensemble remains nevertheless coherent, i.e., it exhibits an oscillatory collective mode (mean field). We show that the system is now in a self-organized quasiperiodic state, predicted in Rosenblum and Pikovsky [ Phys. Rev. Lett. 98, 064101 (2007)]. In this state, frequencies of all oscillators are smaller than the frequency of the mean field, so that the oscillators are not locked to the mean field they create and their dynamics is quasiperiodic. Without a nonlinear phase-shifting unit, the system exhibits a standard Kuramoto-like transition to a fully synchronous state. We demonstrate a good correspondence between the experiment and previously developed theory. We also propose a simple measure which characterizes the macroscopic incoherence-coherence transition in a finite-size ensemble.

We perform experiments with 72 electronic limit-cycle oscillators, globally coupled via a linear or nonlinear feedback loop. While in the linear case we observe a standard Kuramoto-like synchronization transition, in the nonlinear case, with increase of the coupling strength, we first observe a transition to full synchrony and then a desynchronization transition to a quasiperiodic state. However, in this state the ensemble remains coherent so that the amplitude of the mean field is nonzero, but the frequency of the mean field is larger than frequencies of all oscillators. Next, we analyze effects of common periodic forcing of the linearly or nonlinearly coupled ensemble and demonstrate regimes when the mean field is entrained by the force whereas the oscillators are not.

In this study, a new spiral dual-band antenna integrated with an optical system for a small CubeSat spacecraft was proposed. It is challenging to design an antenna with a limited space on a CubeSat platform. To improve the space utilization, an antenna was designed based on the concept of not occupying the sides of the CubeSat. A feature of the proposed antenna system is its compactness, dual-band operation in the L- and S-bands, and possibility of integration with spacecraft cameras. As a result of the study, reflection coefficients of −18 dB and −23 dB and gain of 6.8 dBi and 7.4 dBi, respectively, were achieved at resonant frequencies of 1.7 GHz and 2.45 GHz. The conical shape of the spiral antenna allows the optical system to increase the coverage area, and a simple deployment system with feedback ensures the mission safety. These properties make the proposed antenna suitable for CubeSat systems.

The integrated configuration provides the fastest response time and orientation of the camera with minimal amplitudes, and also results in the lowest power consumption.

CubeSats have become a dominant platform for conducting cost-effective space missions in recent years. This study presents a comprehensive statistical analysis of 2806 CubeSat-class missions launched between 1998 and 2024. The missions are classified into five primary categories – communication, Earth observation, science, education, and technology demonstration-based on their payload functions. Each satellite was further evaluated by form factor and operational status to determine mission success rates. The results show that Earth observation accounts for 39% of all CubeSat missions, with the 3U form factor being the most commonly used and most successful in this domain. Educational missions are significantly underrepresented in launch frequency. Scientific missions, though more frequent, remain below Earth observation and communication in terms of mission volume. A matrix linking mission types, payload categories, form factors, and success outcomes is presented to guide future CubeSat design strategies. A detailed case study of Automatic Dependent Surveillance – Broadcast (ADS-B) payloads was conducted, revealing a 96.9% success rate across over 90 missions. Most of these satellites maintained operations for more than 1000 days, highlighting the reliability and efficiency of ADS-B as a cross-functional payload applicable to communication, Earth observation, and technology demonstration. The findings in this paper provide actionable insights for satellite developers, researchers, and mission planners. By correlating payload types with form factor performance and mission outcomes, this work offers a data-driven framework for optimizing CubeSat mission design and payload integration.

One of the future challenges of increasing the harnessed solar power is efficiency using of CubeSat sides. One of the approaches is using integrated antenna systems with solar panels or payloads. This study proposes a new approach to the use of integrated antenna systems in remote sensing missions. In this approach, due to the integration of antenna system with payload (in our case, with camera), it is possible to achieve a significant increase in the power generation. Calculations are carried out for cases when the antenna system are integrated with the optical system (α = 0°), which implies that they use one plane, in the second case they are spaced at an angle of α = 90° and in the third case when they are directed to opposite sides (α =180°). In the case of α = 0°, where the camera and antenna module are aligned co-axially, there is no energy expenditure for CubeSat orientation. However, in the other two cases, energy is required for rotation and maintenance of the specified orientation throughout the entire duration of the satellite's flight over the ground station, amounting to 111.99 mW when α = 90° and 44.33 mW when α = 180°.