Pin badge of the Infrared Space Observatory (ISO) in blue plastic ESA branded box, by the European Space Agency, 1995-1998

This pin badge depicts the Infrared Space Observatory (ISO), a space telescope designed to study infrared light. It was operated by the European Space Agency, with co-operation from NASA and the Institute of Space and Astronautical Science. Launched in November 1995 in French Guiana from an Ariane 4P rocket, it was operational until May 1998, 10 months longer than expected.

It carried a telescope and an array of four instruments for this study: an Infrared Camera, a photo-polarimeter and Short and Long Wave Spectrometers which allowed for imaging and photometry from 2.5 to 240 micrometres and spectroscopy from 2.5 to 196.8 micrometers.

The Infrared Space Observatory made more than 26000 observations, including detecting Hydrogen fluoride gas for the first time in interstellar gas clouds, detecting the presence of water vapour in numerous places (such as in the vicinity of dying stars), and detecting the earliest stages of stellar formation.