NASA | The MMS Mission’s Unique Orbit

Scientist John Dorelli explains the MMS mission’s orbit and why the four spacecraft fly in a tetrahedron formation. This complex arrangement enables scientists to gather data about magnetic reconnection in 3D. On its journey, MMS will observe a little-understood, but universal phenomenon called magnetic reconnection, responsible for dramatic re-shaping of the magnetic environment near Earth, often sending intense amounts of energy and fast-moving particles off in a new direction. Not only is this a fundam