Energy flow from the Sun into the Earth's magnetosphere averages 1011 W, and at geomagnetically active times it can assume a value of 5 x 1011 W, a value equivalent to the power-generating capacity of all power stations in the U. S. This power is regulated by the hot, tenuous plasma around the Earth; it is temporarily stored in the form of magnetic fields and then explosively released in the form of particle energy. The magnetospheric accelerator powers the auroras in the ionosphere, may disrupt power distribution at high geographic latitudes , and may interrupt telecommunications due to occasional adverse effects on geostationary satellites.
The process of energy circulation through a plasma is ubiquitous across the cosmos, occurring in solar flares, accretion disks, and laboratory devices as well as in the Earth's magnetosphere. Understanding this circulation presents formidable challenges, however, because, as the most recent magnetospheric missions have demonstrated, small-scale processes are driven by and, in turn, control large-scale dynamics. The vast volume of the magnetospheric plasma cannot be fully understood by sampling one point at a given time; global imaging of its strongly interrelated constituent processes is required as well. Although we currently understand the phenomenology of different magnetotail regions and their gross spatial interrelationship, we are still striving in theory and modeling for a satisfactory description of the localized and time-dependent drivers of the magnetospheric circulation. The above problem can only be resolved by monitoring the system in its entirety, both locally and globally.
The Magnetospheric Constellation mission will deploy tens to hundreds of small, autonomous microsatellites to perform continuous, in-situ measurements of the magnetospheric plasma with sufficient resolution to resolve the spatio-temporal ambiguities associated with the driving microphysical processes. These microsatellites can be thought of as the "pixels" of a synthetic magnetospheric image. They will place the localized drivers in the context of the global circulation by providing synoptic three-dimensional images of the circulation of energy and magnetic flux in the magnetosphere, while acquiring detailed particles-and-fields information in the regions where the important microphysical processes occur. Modeling and theory will play a critical role in integrating the data from the various "pixels" into a coherent picture of the dynamic magnetosphere.
By continuously mapping the electrical currents from the ionospheric regulator into the structured magnetosphere while simultaneously monitoring the electrodynamic coupling of the solar wind energy flow through the intricate magnetopause boundary, the Magnetospheric Constellation mission will open a new era in space physics: an era of global, quantitative evaluation of the solar wind-magnetospheric coupling, along with an unobstructed view of the coherent elemental microphysical processes. Technological developments needed to implement the Magnetospheric Constellation mission include novel ways of data relay and microsatellite control, development of lightweight satellite components, autonomous satellite operation (tracking information processing, timing and position knowledge), a probe deployment device, and solar electric propulsion for microsatellite deployment.