The mission builds upon the successes of the ESACluster Mission, but will surpass it in spatial resolution and in temporal resolution, allowing for the first time measurements of the critical electron diffusion region, the site where magnetic reconnection occurs. Its orbit is optimized to spend extended periods in locations where reconnection is known to occur: at the dayside magnetopause—the place where the pressure from the solar wind and the planets' magnetic field are equal—and in the magnetotail—which is formed by pressure from the solar wind on a planet's magnetosphere and which can extend great distances away from its originating planet.
Magnetic reconnection in Earth's magnetosphere is one of the mechanisms responsible for the aurora, and it is important to the science of controlled nuclear fusion because it is one mechanism preventing magnetic confinement of the fusion fuel. The study of turbulence in outer space involves the measurement of motions of matter in stellar atmospheres, like that of the Sun, and magnetic reconnection is a phenomenon in which energy is efficiently transferred from a magnetic field to charged particles.
The principal investigator is James L. Burch of Southwest Research Institute, assisted by an international team of investigators, both instrument leads and theory and modeling experts. The Project Scientist is Thomas E. Moore of Goddard Space Flight Center. Education and public outreach is a key aspect of the mission, with student activities, data sonification, and planetarium shows being developed.
In order to collect the desired science data, the four satellite MMS constellation must maintain a tetrahedral formation through a defined region of interest in a highly elliptical orbit. The formation will be maintained through the use of a next generation space rated GPS receiver, Navigator, to provide orbit knowledge, and regular formation maintenance maneuvers.
Sharma, A. Surjalal; Curtis, Steven A. (2005). "Magnetospheric Multiscale Mission". Nonequilibrium Phenomena in Plasmas. Astrophysics and Space Science Library 321. Springer Netherlands. pp. 179–195. doi:10.1007/1-4020-3109-2_8. ISBN978-1-4020-3108-3.
National Research Council (2003). The Sun to the Earth - And Beyond. National Academies Press. ISBN978-0-309-08972-2.