Aerotecnica Missili & Spazio最新文献

The reduction of components and the development of more powerful satellites with smaller dimensions have allowed an increasing number of users, including universities, research centers, and space agencies in developing countries, to have access to technologies and/or equipment that would have been impossible a few decades ago, paving the way for the development of low-cost space missions. However, the space drive in developing countries includes not only the acquisition of small satellite components, or the construction of CubeSats, but also the creation of spaceports, from which agencies could launch their own delivery vehicles. The rapid worldwide increase of CubeSats, and the long waiting periods between launches of the main payloads, prompted the present investigation, where the main factors to consider in the selection of a spaceport location were stipulated. Therefore, to meet the objective of studying the various factors, a series of points to be analyzed were established: low latitudes, azimuth limitations, natural factors, political and social considerations, airspace, accessibility, and political stability. After analyzing the factors, we proceeded to the analysis of various locations in Venezuela for small space vector missions, where starting from three possible locations and after analyzing each one, we obtained as a result “El Pao”, a location in the Venezuelan plains, far from urban centers, with good communication routes, latitude of only 9° and few azimuth limitations. However, the factors analyzed in this research are not exclusively framed in the Venezuelan space effort as they are common to any country wishing to establish a spaceport in its territory.

Ferrofluid-based systems provide an opportunity for increasing the durability and reliability of systems, where mechanical parts are prone to wear and tear. Conventional reaction control systems are based on mechanically mounted rotating disks. Due to inherent friction, they suffer from degradation, which may eventually lead to failure. This problem is further intensified due to the limited possibility for repair and maintenance. Ferrofluid-based systems aim to replace mechanical components by exploiting ferrofluidic suspended motion. Ferrofluids consist of magnetic nanoparticles suspended in a carrier fluid and can be manipulated by external magnetic fields. This paper describes the working principle, design, and integration of a working prototype of a ferrofluid-based attitude control system (ACS), called Ferrowheel. It is based on a stator of a brushless DC motor in combination with a rotor on a ferrofluidic bearing. The prototype will be verified in a microgravity environment on the International Space Station, as part of the Überflieger 2 student competition of the German Aerospace Center. First ground tests deliver positive results and confirm the practicability of such a system.

Spacecraft fragmentation due to collisions with space debris is a major concern for space agencies and commercial entities, since in the next years the production of collisional fragments is expected to become the major source of space debris. Experimental studies have shown that the fragmentation process is highly complex and influenced by various factors, such as the satellite design, the material properties, the velocity and angle of the debris impact, and the point of collision (e.g., central, glancing, on spacecraft appendages). This paper summarizes the current state of research in spacecraft fragmentation, including the methods and techniques used to simulate debris impacts, the characterization of fragment properties and the analysis of the resulting debris cloud. It provides an overview of the main experiments performed, underlining the most critical issues observed. Moreover, it presents a set of experiments performed at the University of Padova and proposes some future directions for this research.

This study reports on the development of a new Blowdown-Induction Facility driven by two different Oxygen-Fueled Guns. The facility has been conceived and realized to simulate different flow conditions in the context of hypersonic sustained flight. Here the underlying principles are illustrated critically, along with a focused description of the various facility subsystems, their interconnections and the procedures specifically conceived to overcome some of the technical complexities on which this facility relies. Its performances are finally presented in relation to some prototype applications, together with an indication of the related limits, advantages and possible directions for future improvements.

Unmanned flying-test bed aircraft are fundamental to experimentally prove and validate next-generation high-speed technologies, such as aeroshapes design, thermal protection materials, flight mechanics, and guidance–navigation–control in real flight conditions. During the test, the aircraft will encounter realistic operative conditions to assess the accuracy of new design choices and solutions. In this framework, the paper focuses on the longitudinal aerodynamic analysis of an experimental aircraft, with a spatuled forebody aeroshape, from subsonic up to hypersonic speeds. Computational flowfield analyses are carried out at several angles of attack ranging from 0 to 15º and for Mach numbers from 0.1 to 7. Results are reported in detail and discussed in the paper.

In this study, an on-working structural health monitoring system for impact detection on remote piloted vehicle (RPV) airplane is proposed. The approach is based on the propagation of Lamb waves in metallic structures on which Pb[Zr_xTi_1−x]O₃ (PZT) sensors are bonded for receiving vibrational signals due to impact events. The proposed method can be used to detect impacts in aerospace structures, i.e. skin fuselage and/or wing panels. After the detection, machine learning (ML) algorithms (polynomial regression and neural networks) are applied for processing the acquired ultrasounds waves in order to characterise the impacts, in terms of time of flight (ToF) and relative location. Several test cases are studied: the ML models are tested both without external noise (in laboratory) and introducing external RC engine vibration (on-working conditions). Furthermore, this work presents the implementation of a mini-equipment for acquisition and data processing based on Raspberry Pi. A good agreement between laboratory and in-flight results is achieved, in terms of distance between the actual and calculated impact location.