About the ICON mission from the NASA press release:

The Ionospheric Connection Explorer, or ICON, will study the frontier of space: the dynamic region high in our atmosphere where terrestrial weather from below meets space weather from above. Here, the tenuous gases that fill Earth’s upper atmosphere—a mix of neutral and charged particles—are anything but quiet, as vast, high-altitude winds redistribute them throughout the edge of space. These winds can change on a wide variety of time-scales due to factors including Earth’s seasons, the day’s heating and cooling, and incoming bursts of radiation from the Sun.

This region of space, called the ionosphere, and its constant changes have practical repercussions, given our ever-increasing reliance on technology: This is the area through which radio communications and GPS signals travel. Variations here can result in distortions or even complete disruption of such signals. In order to understand this complicated region of near-Earth space, NASA has developed the ICON mission. Understanding what drives variability in the ionosphere requires a careful look at a complex system driven both by terrestrial and space weather.

ICON is a NASA Explorer mission. The Explorers Program Office at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, provides management of the multiple scientific exploration missions within this program. Explorer-class missions are principal investigator- led, relatively moderate cost, small- to medium-sized missions that are capable of being built, tested and launched in a short time interval compared to large observatories.

ICON will help determine the physics of our space environment and pave the way for mitigating its effects on our technology, communications systems and society.