Threats posed by counterspace capabilities are directed against space systems, their supporting ground infrastructure, and data links between space systems and ground infrastructure. Space countermeasures include direct attack and co-orbital anti-satellite systems, cyber attacks, electronic warfare and directed energy. This is condition, however, of the impossibility of stationary dominance and control exacerbates the need to develop opportunities to influence the enemy's satellites, while at the same time guaranteeing the sustainable operation of one's own space capabilities. This can be accomplished by ground or space-based means. Since outer space is a vacuum and is incommensurable with the Earth's atmosphere, the change in the trajectory of satellites in space is fundamentally different from the change in the trajectory of combat aircraft. The movement of satellites in a vacuum along a certain orbit, due to the distortion of space by the planet Earth, leads to movement at a much higher speed than all aircraft flying in the earth's atmosphere, and the movement in the orbit does not require thrust compared to airplanes. When it is necessary, however, to change the satellite's trajectory, energy is required to be expended by changing the satellite's velocity ΔV. This is usually achieved by burning chemical fuels or expelling accelerated gases through a propulsion system.

In the dynamic world of aerospace engineering, the search for innovative materials has always been at the forefront. The aerospace industry relies heavily on alloys that can withstand extreme conditions, maximize performance, and minimize weight and cost. As we move into the future, several alloys have emerged as the most promising candidates for aerospace applications. Here are a few of the most promising alloys for aerospace applications: composites, nickel-based superalloys, titanium aluminides, high entropy alloys, shape memory alloys, etc. This article provides a brief overview of some of these extraordinary materials that outline a brighter future for the aerospace industry. The article offers a dialogue and cites particular innovations originating from Bulgaria. Future directions for research in this field are explored.

In presented paper, linearized and nonlinear mathematical models of three-dimensional motion of Douglas DC-8-63 transport aircraft are considered. A source code was developed in GNU Octave environment by means of which serial computations were made for impulse deviations of elevator and ailerons. The results obtained from both the linearized and the non-linear model are shown graphically, compared, and commented.

Mardirossian, G. Prirodni bedstvija i ekologichni katastrofi – izuchavane, prevencija, zashtita. Izdatelstvo na BAN „Prof. Marin Drinov”, Sofia, 2024, 359 p. ISBN 978-619-245-452-4 (in Bulgarian).

The exploitation of space has led to the emergence of many medical innovations for earthly use, and the pace of development of science and technology has increased, especially, and it is not for nothing that our time is called the time of scientific and technological progress. Today we know our own planet better than ever. This means that space exploration really improves human life, increases humanity's collective knowledge, and helps build a modern society.

The present study examines the application of two vegetation indices, SAVI and MSAVI, to advance our understanding of the state of beech forest habitats. The research object is Boatin Reserve, located in Central Bulgaria. Landsat eight images were derived, and beech forest habitats were used as the basic territorial unit for the analysis. The main focus was the months of June, July, and August. The results of the study showed certain patterns. Luzulo-Fagetum beech forests (9110), Asperulo-Fagetum beech forests (9130), and Moesian beech forests (91W0) are the beech forest habitats within the study area. MSAVI results were higher than those of SAVI.

The aim of this paper is to summarize the Project Management techniques and methodologies used by NASA during the specified period. The transition from a Predictive perspective to an Adaptive perspective, and software project types are visualized in this picture. This Research Case Study aims to demonstrate the advantages of iterative and adaptive models.

In this paper, we study the physical processes between two nova outbursts of the symbiotic binary star T CrB. We present our theoretical hypothesis on the binary evolution during 80-year period between similar states of the whole cycle. Our hypothesis consists of five consequent stages. We found that during the third stage of the suggested scenario, the accretion disk is reduced, which means a higher accretion intensity. The reduced disk’s radius and the donor star’s orbital contraction are calculated. To support our theoretical hypothesis, we compare the current results of T CrB with our previous results of the recurrent nova RS Oph, which shows a similar model’s behaviour.

This paper examines the Urban Heat Island (UHI) phenomenon across ten regions in Greece, leveraging Google Earth Engine (GEE) to process and analyze remotely sensed data. UHI intensity is assessed by calculating Land Surface Temperature (LST) and the Urban Thermal Field Variance Index (UTFVI), allowing for precise monitoring of thermal variations in urban and peri-urban environments. The selected study areas are characterized by varied population densities and geographic features, providing insights into how urbanization, land use, and climatic conditions influence UHI intensity. Results indicate significant seasonal and spatial variability in UHI patterns, with inland regions experiencing greater thermal stress compared to coastal areas, partly due to the moderating effects of sea breezes. Notably, urban planning and green infrastructure are shown to play a critical role in reducing UHI impact, underscoring the need for sustainable urban planning practices. This research highlights the importance of UHI monitoring to inform mitigation strategies and assess the socio-economic costs associated with heat stress, particularly under conditions of rapid urban expansion and climate change. ).

Fractal analysis is performed on the topography to investigate the terrain of the planet Mars. Several hypsometry layers and areal analysis revealed the diversity of the Northern and Southern hemispheres – the first one dominated by basins, the second by mountains. The calculated fractal dimensions (FD) are a simple measure of the fragmentation of the determined layers. The analysis of the values of those dimensions reveals similarities and differences between the divided hypsometric layers. The results obtained give a possibility to announce a hypothesis of the domination of external factors in the shaping role of marsodynamics in the formation of the terrain, both in the past geological times and in recent times.