Solar modulation model with reentrant particles

We developed a one dimensional model of particle transport in the heliosphere. As opposite to widely used models, we apply a method where a quasi-particle is traced back in time. The model gives us the possibility to work on the possible existence of reentrant particles in the heliosphere that can be hardly solved by the traditional forward tracking method. Particles escape from the heliosphere and may reenter back. We estimate how these particles affect the modulation process in the heliosphere. Presented here are the results for different values of particles mean free path in the interstellar space and for different interstellar magnetic field values.     

Innovation and change? The evolution of Europe's small satellite manufacturers

Since the 1980s a trend has emerged to contain the cost of space missions, which has favored trials in the construction and launch of small satellites. This effort has considerably reduced the cost of the satellites because the construction process uses both traditional components and important technological innovations. There have also been market openings for small satellites, both within the telecommunication sector and for scientific missions and those related to Earth observation. This paper contains the results of a survey of the largest manufacturers of small satellites in Europe and investigates how far (if at all) they have changed the structure of the European space industry. It finds that, through the acquisition of small satellite manufacturers, traditional large companies operating in the field of space in Europe have secured for themselves important technological innovations and market opportunities, while maintaining their oligopolistic position.     

Discovering the basic strategic orientation of big space agencies

The aim of this paper is to identify the basic strategic orientations of some of the world's main space agencies. This study focuses on the Brazilian, French, European, Japanese, Indian and Russian agencies. Basic strategic orientations indicate the real space exploration objectives of large countries. This is useful because there are some ambiguous areas in the formal strategic documents published by these agencies. The results highlight the common objectives of the agencies studied, which is to have an important role in international political leadership even considering the specific objectives related to the economic and social contexts of the individual countries.     

Effects of solar modulation on the cosmic ray positron fraction

We implemented a 2D Monte Carlo model to simulate the solar modulation of galactic cosmic rays. The model is based on the Parker’s transport equation which contains diffusion, convection, particle drift and energy loss. Following the evolution in time of the solar activity, we are able to modulate a local interstellar spectrum (LIS), that we assumed isotropic beyond the termination shock, down to the Earth position inside the heliosphere. In this work we focused our attention to the cosmic ray positron fraction at energy below ∼10 GeV, showing how the particle drift processes could explain different results for AMS-01 and PAMELA. We compare our modulated spectra with observations at Earth, and then make a prediction of the cosmic ray positron fraction for the AMS-02 experiment.     

Space technology transfer policies: Learning from scientific satellite case studies

The paper reports research into the transfer of technology typically used in the construction of scientific satellites. Four case studies are analyzed to clarify some basic mechanisms of the transfer of space technology to the industrial system. The paper finds that the technologies analyzed in the construction of satellites for the most part stem from the integration of technical processes already known in various industrial sectors; the use of these processes in space involves their substantial strengthening and upgrading in terms of performance; and this upgrading permits them to return to industrial sectors that use the technological advances acquired for coping with complex problems in the space sector. This research has helped validate some of the determinants of technology transfer already noted in the literature, while increasing the number and content of these. Useful indications emerge for policy makers and agents involved in technology transfer programs.     

Experimental Investigation to Evaluate LiFePO4 Batteries Anode and Cathode Elastic Properties under Cyclic Temperature Loading Conditions

Experimental investigations and associated methods are provided to characterize the mechanical properties of a lithium-ion battery accounting for operating temperature variation and thermal effects. Material properties for LiFeP04 cathode and anode samples taken from an off-the-shelf battery are evaluated in new and fatigued （subjec- ted to charging and discharging cycles） conditions.     

Thin Film Lithium-Ionbatteries Crack Initiation Due to Thermal and Electric Effects

The transient and thermo-electric finite element analysis （FEA） of a 2D lithium-on （Li-ion） battery is presented. The process of recharging and discharging of thin film lithium-ion （LiFePO4） battery in the presence of a transversal crack is numerically investigated. During this process significant temperature load influences the be- havior of the battery and thermal fields can affect the way crack propagates into the thin film media. The simula- tions infer about relationship between temperature and electric field and their effect on crack propagation. A Li-ion battery model suitable for this investigation is implemented in the multi-physics software package by COMSOL Inc. , and it is extended to include the thermal and electrical effects. Results and discussion are accompanied with pertinent conclusions.     

Fluxes and nuclear abundances of cosmic rays inside the magnetosphere using a transmission function approach

At 1 AU and outside the Earth’s magnetosphere, the relative abundances to protons for He (He/p), C (C/p) and Fe (Fe/p) nuclei were calculated using the observation data of AMS-01 (for p and He) and HEAO-3 (for C and Fe) above 0.8 GeV/nucleon. In addition, the transmission function (TF) for the GCR propagation inside the magnetosphere was evaluated using the IGRF and T96 (introduced by Tsyganenko and Stern) models to obtain permitted and forbidden trajectories inside the magnetosphere. The TF allowed one to derive the primary He-nuclei fluxes in the same geomagnetic regions of AMS-01 observations. These fluxes were found in good agreement with the observation data. Furthermore inside the magnetosphere in addition to the flux of helium, it allowed one to obtain those of the primary p, C, and Fe nuclei and the relative abundances of He, C and Fe nuclei to protons from the same observation data of AMS-01 and HEAO-3 above ≈0.8 GeV/nucleon. Up to a geomagnetic latitude of ≈45.84°, the relative isotopic abundances were found to depend on the mass number I_isot and, on average, range from a factor ≈2.31 up to ≈3.35 larger than those outside the magnetosphere at 1 AU. Thus, the magnetospheric isotopic/nuclear relative abundances differ from those inside the solar cavity and those in the interstellar space. The usage of the TF approach can allow one to determine the nuclear abundances in the magnetosphere at any geomagnetic latitude and, thus, any orbit, provided that the CR spectra are determined at 1 AU.     

Guided propagation of HF radio waves in the ionosphere

A review is given of the work done in the field of ionospheric guided propagation of HF radio signals from artificial satellites. The possible theoretical approaches to the problem are summarized with more details on the analysis in terms of ray-tracing based on a geometric-optics treatment.A survey is done of the experimental observations performed through satellite transmissions, with particular emphasis on the results obtained through three ad hoc developed experiments: Orbis, S. Marco and OV 4.