ICON (Ionospheric Connection Explorer)

What is ICON?

The lonospheric Connection Explorer (ICON) is a NASA Small Explorer mission lead by Dr. Thomas Immel at The University of California, Berkeley. UTD is a mission science partner, led by Dr. Rod Heelis and supported by Dr. Russell Stoneback and Dr. Yun-Ju Chen. With support from the UTD Space Sciences engineering staff, UTD provided the ICON Ion Velocity Meter payloads.

Mission Objectives

ICON studies 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 timescales 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. The ICON mission objective is to understand this complicated region of near-Earth space including the drivers of variability in the atmosphere.

Launch and Operation

The ICON satellite launched from NASA’s Kennedy Space Center, carried to orbit by the Northrop Grumman Pegasus XL launch vehicle. Unlike most satellite launches that use a ground-launched rocket to carry the satellite to orbit, the Pegasus XL carries the rocket to high altitude using a special Lockheed L-1011 airplane. After separating from the plane, the rocket engine ignites and carries the satellite to orbit.

ICON successfully reached orbit and began operation on October 11, 2019 at an initial altitude of 575 km and an orbit inclination of 27°. Mission operations are carried out at the U.C. Berkeley Space Sciences Laboratory Mission Operation Center.

The ICON Payloads

FUV

(Far Ultra Violet Imaging Spectrograph)
Developed by UC Berkeley, CA During the daytime, the FUV imager determines the upper atmospheric composition.
At nighttime, it measures altitude profiles of ion density.

EUV

(Extreme Ultraviolent Spectrograph)
Developed by UC Berkeley, CA The EUV spectrograph measures the density of ionized gases during the daytime.

IVM A & B

(lan Velocity Meter)
Developed by UT Dallas, TX
The IVM measures the motion, temperature, and total ion number density of ionized gases at the location of the spacecraft.

MIGHTI A & B

(Michelson Interferometer for Global High-resolution Thermospheric Imaging)
Developed by Naval Research Lab DC The MIGHTI interferometer determines the altitude profiles of atmospheric wind and temperature in the Earth’s apper atmosphere.

On-Orbit Observations

The ICON observations combine measurements of the local plasma and the remote neutral atmosphere to retrieve all properties of the system that influences the coupling between the ionosphere and the atmosphere. IVM meaurements at the satellite location map along magnetic field lines to the remote viewing point of the EUV, FUV and MIGHTI instruments, yielding a unique characterization of the behavior of the thermosphere.