It is an unmanned space mission to study the Earth’s magnetosphere, using four identical satellites flying in a tetrahedral or pyramid formation.
Objectives:
The mission launched in March 2015 aims to map magnetic reconnection, a process that occurs as the sun and Earth’s magnetic fields interact.
Understanding causes of magnetic reconnection is important for understanding phenomena of auroras on Earth, flares on surface of sun, and areas surrounding black holes.
The mission is also designed to gather information about the microphysics of energetic particle acceleration and turbulence, processes that occur in many astrophysical plasmas.
Significance:
When these satellites are closest to Earth, they move at up to 35,405 km/hour, making them the fastest known operational use of a GPS receiver.
These satellites operate in a highly elliptical orbit around Earth and incorporate GPS measurements into their precise tracking systems.
This system which require extremely sensitive position and orbit calculations to guide tight flying formations.