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The supply of electrical power is one of the most important functions required by the diverse payloads of satellites. A fault in the corresponding subsystem might lead to mission or even vehicle loss. Among the causes of such faults, we highlight the phenomenon of thermal avalanche in batteries. It can be explained as an energetic unbalance where the rate of heat generated in the interior of the system exceeds its capacity to dissipate it. This occurred to the OAO1 of NASA just after its launch on April 8, 1966; and with the CBERS2 of CAST and INPE already in orbit in 2007 and 2009. This work presents a discussion on the causes and effects of thermal avalanches in artificial satellite battery charging and discharging systems.

The increasing development of Unmanned Aerial Vehicle (UAV) technologies has allowed greater use of UAVs as remote sensing platforms to enhance satellite and manned aerial vehicle remote sensing surveillance and environmental management systems. Particularly, the Brazilian National Institute for Space Research - INPE has an Environmental Data Collection System (SCD) since 1993. Recently, the MCTI (Ministry of Science, Technology and Innovation) opened the National Center for Monitoring and Early Warning of Natural Disasters (CEMADEN). Both may need additional resources for their expansions in the near future as offered by UAV technologies. These needs illustrate the potential of UAV technologies as complement to existing or future systems. This paper presents an overview of data transmission used in UAVs for remote sensing surveillance and environmental management systems.

Control systems that can switch between control modes have the advantage of being simpler to design than an equivalent system with a single mode. However, the transition between control modes can introduce steps or overshootings in the state variables, and this can degrade the performance or even damage the system. In this work, we will use integral criteria in an original way, to determine a coefficient on the system which should optimize the trajectory of the control signal, during the switching between two modes. Effectively, each transition will be done by a subsystem specific for it, according to the selected criterion. The simulations will be made in MATRIXx, using as models the system of control of attitude of the Multimission Platform, and a system which keeps the synchrony between two induction motors.