MMS 1-4

NASA's Magnetospheric Multiscale mission put four identical spacecraft into a coordinated formation to study magnetic reconnection - the process by which magnetic field lines break and reconnect, explosively releasing energy and flinging particles to near-light speeds. Flying together, the probes provided the first three-dimensional view of reconnection in progress. Each carried instruments operating at 100 times the sampling rate of any prior spacecraft, fast enough to capture measurements inside the electron diffusion region where the physics of reconnection unfolds.