Physical modeling of electromagnetic interferences in the unmanned aerial vehicle in the case of high-voltage transmission line impact

A technique has been developed for studying the interference resistance of electronic systems for unmanned aerial vehicles based on physical modeling The paper proposes mathematical models, a scheme of a test stand and examples of parameter calculation for physical modeling of electromagnetic interferences in communication links of the unmanned aerial vehicle in the case of electromagnetic fields of high-voltage transmission lines interference. Examples demonstrating successful implementation of physical modeling for similar tasks ascertain the feasibility of this approach.     

Old-Aged Primary Distance Indicators

Old-aged stellar distance indicators are present in all Galactic structures (halo, bulge, disk) and in galaxies of all Hubble types and, thus, are immensely powerful tools for understanding our Universe. Here we present a comprehensive review for three primary standard candles from Population II: (i) RR Lyrae type variables (RRL), (ii) type II Cepheid variables (T2C), and (iii) the tip of the red giant branch (TRGB). The discovery and use of these distance indicators is placed in historical context before describing their theoretical foundations and demonstrating their observational applications across multiple wavelengths. The methods used to establish the absolute scale for each standard candle is described with a discussion of the observational systematics. We conclude by looking forward to the suite of new observational facilities anticipated over the next decade; these have both a broader wavelength coverage and larger apertures than current facilities. We anticipate future advancements in our theoretical understanding and observational application of these stellar populations as they apply to the Galactic and extragalactic distance scale.     

The OSIRIS-REx Visible and InfraRed Spectrometer (OVIRS): Spectral Maps of the Asteroid Bennu

The OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) is a point spectrometer covering the spectral range of 0.4 to 4.3 microns (25,000–2300 cm^?1). Its primary purpose is to map the surface composition of the asteroid Bennu, the target asteroid of the OSIRIS-REx asteroid sample return mission. The information it returns will help guide the selection of the sample site. It will also provide global context for the sample and high spatial resolution spectra that can be related to spatially unresolved terrestrial observations of asteroids. It is a compact, low-mass (17.8 kg), power efficient (8.8 W average), and robust instrument with the sensitivity needed to detect a 5% spectral absorption feature on a very dark surface (3% reflectance) in the inner solar system (0.89–1.35 AU). It, in combination with the other instruments on the OSIRIS-REx Mission, will provide an unprecedented view of an asteroid’s surface.     

Low Altitude Cusp–Cleft Region Signatures of Strong Geomagnetic Disturbances

The polar cusp being a region of the free access of the solar wind into the inner magnetosphere is also the site of turbulent plasma flow. The cusp area at low altitudes acts like a focus of a variety type of instability and disturbances from different regions of the Earth. Daily f ₀ F2 frequencies are discussed regarding the cusp position. The high time resolution wave measurements together with electron and ion energetic spectra measurements registered on the board the Freja satellite and Magion-3 and the electron density at the peak of f ₀ F2 layers collected from ground-based ionosonde measurements were used to study the response of ionospheric plasma within the cusp–cleft region to the strong geomagnetic storm. In this paper we present the response of the ionospheric plasma to the disturbed conditions seen in the topside wave measurements and in the ionospheric characteristics maps obtained from the ground-based VI network. The need of the cusp feature model for radio communication purposes is advocated.     

Effect of Variable Selection on Multidisciplinary Design Optimization： a Flight Vehicle Example

Different multidisciplinary design optimization (MDO) problems are formulated and compared. Two MDO formulations are applied to a sounding rocket in order to optimize the performance of the rocket. In the MDO of the referred vehicle, three disciplines have been considered,which are trajectory, propulsion and aerodynamics. A special design structure matrix is developed to assist data exchange between disciplines. This design process uses response surface method (RSM) for multidisciplinary optimization of the rocket. The RSM is applied to the design in two categories: the propulsion model and the system level. In the propulsion model, RSM deter-mines an approximate mathematical model of the engine output parameters as a function of design variables. In the system level, RSM fits a surface of objective function versus design variables. In the first MDO problem formulation, two design variables are selected to form propulsion discipline. In the second one, three new design variables from geometry are added and finally, an optimization method is applied to the response surface in the system level in order to find the best result. Application of the first developed multidisciplinary design optimization procedure increased accessible altitude (performance index) of the referred sounding rocket by twenty five percents and the second one twenty nine.     

Fine structure of the interplanetary shock front according to measurements of the ion flux of the solar wind with high time resolution

According to the data of the BMSW/SPEKTR-R instrument, which measured the density and velocity of solar wind plasma with a record time resolution, up to ~3 ×10^–2 s, the structure of the front of interplanetary shocks has been investigated. The results of these first investigations were compared with the results of studying the structure of the bow shocks obtained in previous years. A comparison has shown that the quasi-stationary (averaged over the rapid oscillations) distribution of plasma behind the interplanetary shock front was significantly more inhomogeneous than that behind the bow-shock front, i.e., in the magnetosheath. It has also been shown that, to determine the size of internal structures of the fronts of quasi-perpendicular (θ_BN > 45°) shocks, one could use the magnetic field magnitude, the proton density, and the proton flux of the solar wind on almost equal terms. A comparison of low Mach (М _А < 2), low beta (β₁ < 1) fronts of interplanetary and bow shocks has shown that the dispersion of oblique magnetosonic waves plays an essential role in their formation.     

A Theoretic Interpretation of Movement of the Cusp Equatorward Boundary

A preliminary model is proposed to describe quantitatively the position and movement of cusp equatorward boundary. This integrated model, consisting of an empirical model of the magnetopause and a compressed dipolar model of Open/Closed field line, connects quantitatively the solar wind conditions, subsolar magnetopause and cusp equatorward boundary. It is shown that the increasing solar wind dynamic pressure and the increasing southward Interplanetary Magnetic Field (IMF) component drive the magnetopause to move inward and the cusp equatorward. This model is adopted to interpret quantitatively the cusp movement of August 14, 2001 observed by Cluster. The results show that the subsolar magnetopause moved earthward from 10.7 He to 9.0 Re during the period of 002300-002800 UT, and correspondingly the cusp equatorward boundary shifted equatorward. The observations of Cluster C1 and C4 show the cusp equatorward boundary that Cluster Cl and C4 were crossing during same interval moved equatorward by 4.6°. The cusp equatorward boundary velocity computed in the theoretical model (10.7km/s) is in good agreement with the observed value (9.4km/s) calculated from the data of CIS of Cluster C4 and C1.     

Space flight experiment on Chinese silkworm on board the Russian 10th Biosatellite.

Space flight experiments on Chinese silkworm (Bombyx mori L.) were conducted on board the Russian 10th Biosatellite for 12 days. The samples included silkworm eggs, larvae, cocoons, pupae and moths. The processes of spinning, cocooning, mating, oviposition, larval hatching, pupation and moth emergence all completed well in space. The following effects of space flight on silkworm development were observed: The times of hatching and oviposition in the flight group were 2 to 3 days earlier than in the control group; the hatching rate of diapause eggs during space flight seemed higher than that of the control group; the life span of 2 of the 7 varieties flown was shortened; genetical variations appeared in 3 varieties. The results showed that the embryonic stage was probably the period most sensitive to the space flight environment.     

Critical Issues on Magnetic Reconnection in Space Plasmas

The idea of expedient energy transformation by magnetic reconnection (MR) has generated much enthusiasm in the space plasma community. The early concept of MR, which was envisioned for the solar flare phenomenon in a simple two-dimensional (2D) steady-state situation, is in dire need for extension to encompass three-dimensional (3D) non-steady-state phenomena prevalent in space plasmas in nature like in the magnetosphere. A workshop was organized to address this and related critical issues on MR. The essential outcome of this workshop is summarized in this review. After a brief evaluation on the pros and cons of existing definitions of MR, we propose essentially a working definition that can be used to identify MR in transient and spatially localized phenomena. The word “essentially” reflects a slight diversity in the opinion on how transient and localized 3D MR process might be defined. MR is defined here as a process with the following characteristics: (1) there is a plasma bulk flow across a boundary separating regions with topologically different magnetic field lines if projected on the plane of MR, thereby converting magnetic energy into kinetic particle energy, (2) there can be an out-of-the-plane magnetic field component (the so-called guide field) present such that the reconnected magnetic flux tubes are twisted to form flux ropes, and (3) the region exhibiting non-ideal MHD conditions should be localized to a scale comparable to the ion inertial length in the direction of the plasma inflow velocity. This definition captures the most important 3D aspects and preserves many essential characteristics of the 2D case. It may be considered as the first step in the generalization of the traditional 2D concept. As a demonstration on the utility of this definition, we apply it to identify MR associated with plasma phenomena in the dayside magnetopause and nightside magnetotail of the Earth’s magnetosphere. How MR may be distinguished from other competing mechanisms for these magnetospheric phenomena are then discussed.This revised version was published online in July 2005 with a corrected cover date.