MMS: Mission Implementation (I)

Regions of Scientific Interest

Magnetic reconnection occurs in two main regions of Earth's magnetosphere: (1) the dayside magnetopause and (2) the nightside magnetotail. MMS will employ a two-phase orbit strategy to explore each of these regions in turn.

In Phase 1, MMS will probe reconnection sites at the mid-latitude dayside magnetopause. Here the interplanetary magnetic field (IMF) merges with the geomagnetic field, transferring mass, momentum, and energy to the magnetosphere. The solar wind flow transports the merged IMF/geomagnetic field lines toward the nightside, causing a build up of magnetic flux in the magnetotail. In Phase 2, the MMS constellation will investigate reconnection sites in the nightside magnetotail, where reconnection releases the magnetic energy stored in the tail in explosive events known as magnetospheric substorms and allows the magnetic flux stripped away from the dayside magnetopause by the solar wind/magnetosphere interaction to return to the dayside.

Orbit Design