Physical Conditions in Space

Abstract

Increasing needs and interests of the humankind in space exploration and monitoring require to study very seriously the effects of space environment on spacecraft and, in this context, to improve significantly the Space Weather predictions (see Chapters 7–8). It does not admit of doubt that physical conditions in space are determined originally by the current level of solar activity. This level depends on time and reveals the variations in the course of 11-year solar activity cycle. The main constituents of the physical conditions in space are solar wind and interplanetary magnetic fiield (IMF) that govern charged particle motion at large time and spatial scales. Also, such a dynamic phenomenon as shock waves in solar wind plasma cause very significant changes of electromagnetic situation in the interplanetary space. In the nearest environment of the Earth a main factor in the particle behaviour is the geomagnetic field with its spatial and temporal variations.