[9] ICON was equipped with four instruments: a Michelson interferometer, built by the United States Naval Research Laboratory (NRL) to measure the winds and temperatures in the thermosphere; an ion drift meter, built by University of Texas at Dallas to measure the motion of charged particles in the ionosphere; and two ultraviolet imagers built at University of California, Berkeley to observe the airglow layers in the upper atmosphere in order to determine both ionospheric and thermospheric density and composition.

Many low-Earth orbiting satellites, including the International Space Station (ISS), fly through the ionosphere and can be affected by its changing electric and magnetic fields.

The ionosphere is where space weather manifests, creating unexpected conditions; electric currents can cause electrical charging of satellites, changing density can affect satellite orbits, and shifting magnetic fields can induce current in power systems, causing strain, disrupting communications and navigation or even triggering blackouts.

ICON carried four scientific instruments designed to image even the faintest plasma or airglow to build up a picture of the ionosphere's density, composition and structure.

[18] The velocity measurements were gathered by observing the Doppler shift in the red and green lines of atomic oxygen.

[19] IVM collected in situ data about ions in the local environment around the spacecraft, whereas EUV and FUV were spectrographic imagers.

EUV was a 1-dimension limb imager designed to observe height and density of the daytime ionosphere by detecting the glow of oxygen ions and other species at wavelengths between 55 and 85 nm.

FUV was a 2-dimension imager that observes the limb and below at 135 and 155 nm, where bright emissions of atomic oxygen and molecular nitrogen are found.

A fail-safe system, designed to reset the spacecraft computer after 8 days with no receipt of commands from the ground, failed to restore communications after it elapsed on 5 December 2022.