An instrument that monitors and measures energetic heavy ions in space. The Galileo space probe had an HIC that is composed of two Low-Energy Telescopes (LETs), which were solid-state detector telescopes. An HIC uses stacks of silicon wafers to measure the heavy ions that hit the spacecraft, since this can cause changes in the vehicle's electronics. The data can be used to design more resistant electronics for future missions. The Galileo HIC had also been used to monitor and investigate this type of radiation around the planet Jupiter and to observe heavy ions associated with solar flares and cosmic rays.