Cosmic Background Explorer
In the early 1980s there were only upper limits available for the CIB. The real observations of the CIB began after the era of astronomical satellites working in the infrared, started by the Infrared Astronomy Satellite (IRAS), and followed by the Cosmic Background Explorer (COBE), the Infrared Space Observatory (ISO) and by the Spitzer Space Telescope. Exploration of the CIB was continued by the Herschel Space Observatory, launched in 2009.