Documents the science, the mission, the spacecraft and the instrumentation on a unique NASA mission to study the Earth’s dynamic, dangerous and fascinating Van Allen radiation belts that surround the planet This collection of articles provides broad and detailed information about NASA’s Van Allen Probes (formerly known as the Radiation Belt Storm Probes) twin-spacecraft Earth-orbiting mission. The mission has the objective of achieving predictive understanding of the dynamic, intense, energetic, dangerous, and presently unpredictable belts of energetic particles that are magnetically trapped in Earth’s space environment above the atmosphere. It documents the science of the radiation belts and the societal benefits of achieving predictive understanding. Detailed information is provided about the Van Allen Probes mission design, the spacecraft, the science investigations, and the onboard instrumentation that must all work together to make unprecedented measurements within a most unforgiving environment, the core of Earth’s most intense radiation regions. This volume is aimed at graduate students and researchers active in space science, solar-terrestrial interactions and studies of the upper atmosphere. Originally published in Space Science Reviews, Vol. 179/1-4, 2013.

Since the discovery of geomagnetically trapped radiation by Van Allen in 1958, an impressive amount of experimental information on the earth's particle and field environment has nourished research work for scores of scientists and thesis work for their students. This quest has challenged space-age technology to produce better and more sophisticated instru ments and has challenged the international scientific community and governments to establish more, and more effective, cooperative programs of research and information exchange. As a result, an orderly picture of the principal physical mechanisms governing the earth's radiation environment is beginning to emerge. The interest in this topic has reached far beyond the domain of geo physics. Indeed, we find trapped radiation elsewhere in the universe: Jupiter's radiation belts, particle trapping in sunspot magnetic fields, cosmic rays confined in interstellar fields and, possibly, ultra-high-energy particles trapped in the magnetic fields of rotating neutron stars. There is abundant technical and scientific literature available on Van Allen radiation; comprehensive reviews are published regularly in journals* or have been collected in book form**, and books have been written on the subject***. The aim of this monograph is to complement the existing literature with a concise discussion of the basic dynamical processes that control the earth's radiation belts. It is mainly intended to help a graduate student or a researcher new to this field to understand the underlying physics and to provide him with guidelines for quantita tive, numerical applications of the theory.

The mono graph contains 8 chapters, and their contents cover all principal aspects of the problem: 1. Introduction and brief his tory ofthe radiation problem and background information ofradiation hazard in the near-Earth and interplanetary space. 2. General description of radiation conditions and main sources of charged partic1es in the Earth's environment and interplanetary space, effects of space environment on spacecraft. 3. Basic information about physical conditions in space and main sources of charged particles in the Earth's environment and interplanetary space, in the context of "Space W eather" monitoring and prediction. 4. Trapped radiation belts of the Earth (ERB): theory of their origin, spatial and temporal dynamics, and experimental and statistical models. 5. Galactic cosmic rays (GCR): variations of energetic, temporal and spatial characteristics, long-term modulation, and anomalous cosmic ray (ACR) component, modeling oftheir dynamics. 6. Production of energetic particles (SEPs) at/ne ar the Sun: available databases, acceleration, propagation, and prediction of individual SEP event, statistical models of solar cosmic rays (SCR). 7. Existing empirical techniques of estimating, prediction and modeling of radiation hazard, methodical approaches and constraints, some questions of changes in the Earth's radiation environment due to changes of the solar activity level. 8. Unresolved problems of radiation hazard prediction and spacecraft protection, radiation experiments on board the spacecraft, estimating of radiation conditions during interplanetary missions. Space does not allow us to explain every time the solar-terrestrial and radiation physics nomencIature used in current English-language literature.

The advent of artificial earth satellites in 1957-58 opened a new dimension in the field of geophysical exploration. Discovery of the earth's radiation belts, consisting of energetic electrons and ions (chiefly protons) trapped by the geomagnetic field, followed almost immediately [1,2]' This largely unexpected development spurred a continuing interest in magnetospheric exploration, which so far has led to the launching of several hundred carefully instrumented spacecraft. Since their discovery, the radiation belts have been a subject of intensive theoretical analysis also. Over the years, a semiquantitative understanding of the governing dynamical processes has gradually evol ved. The underlying kinematical framework of radiation-belt theory is given by the adiabatic theory of charged-particle motion [3J, and the interesting dynamical phenomena are associated with the violation of one or more of the kinematical invariants of adiabatic motion. Among the most important of the operative dynamical processes are those that act in a stochastic manner upon the radiation-belt particles. Such stochastic processes lead to the diffusion of particle distributions with respect to the adiabatic invariants. The observational data indicate that some form of particle diffusion plays an essential role in virtually every aspect of the radiation belts.

Magnetosphere refers to that area of space around a planet that is controlled by that planet's magnetic field. It protects the Earth from certain types of radiation from the Sun. The inner magnetosphere is the region of magnetosphere that contains the plasmasphere, ring current, and the radiation belts all co-located within about 6.6 times of the Earth's radius. These belts are highly dynamic, increasing, and decreasing on time scales of minutes to years. A radiation belt refers to the zone of energetic charged particles that generally originates from the solar wind that is captured by and held around a planet by that planet's magnetosphere. Radiation belts are regions of enhanced populations of energetic electrons and protons surrounding the Earth in space. There are two radiation belts of Earth, the inner radiation belt and the outer radiation belt. This book outlines the dynamics of the Earth's radiation belts and inner magnetosphere in detail. It is a resource guide for experts as well as students.