The Magnetospheric Multiscale Mission (MMS) is a NASA unmanned space mission to study the Earth's magnetosphere, using four identical spacecraft flying in a tetrahedral formation. The spacecraft were launched on 13 March 2015 at 02:44 UTC. It is designed to gather information about the microphysics of magnetic reconnection, energetic particle acceleration, and turbulence, processes that occur in many astrophysical plasmas.