The NASA mission Magnetospheric Multiscale (MMS) is to explore the dynamics of the Earth's magnetosphere and its underlying energy transfer processes. Four identically equipped spacecraft are to carry out three-dimensional measurements in the Earth's magnetosphere. The MMS satellites will constitute a further milestone after the very successful ESA mission Cluster, but they are to fly at even closer mutual distances and investigate different regions of near-Earth space in several mission phases.

At the center of the investigations is the so-called magnetic reconnection, a process that converts magnetic energy into kinetic energy of particles, causing magnetic storms and phenomena such as the aurora. MMS is to measure the physics of the reconnection process including the factors that control it, its spatial distribution, and its temporal behavior in great detail. The data from MMS are also expected to provide further insight into the Sun and its influence on the Earth and the solar system.

NASA selected the Southwest Research Institute (SwRI), San Antonio, USA, to lead the mission. At present, the MMS mission is scheduled for launch in 2014. Each payload has the most comprehensive fields and fast plasma suite ever flown. It includes the FIELDS suite for electric and magnetic field measurements with several sensors each, three instrument packages for particle measurements with focus on high temporal resolution, composition, and high energy particles, and finally instruments to control the spacecraft potential.

The lead institutions for the instrument suites and other key elements of the mission are - besides SwRI - the University of New Hampshire, the Goddard Space Flight Center, the Applied Physics Laboratory, and IWF Graz. IWF has taken the lead for the spacecraft potential control of the satellites (ASPOC) and participates in the electron beam instrument (EDI) and the digital fluxgate magnetometer (DFG).

Further information on MMS is found at NASA and SwRI.