ESA has adopted Ariel (Atmospheric Remote-sensing Infrared Exoplanet Large-survey), the 4th medium-class space mission of its Cosmic Vision program. Ariel is expected to be launched in 2029 by Ariane 6 from the Guiana Space Centre in Kourou.

On May 18th 2020, ESO formally closed the preliminary design review of the ELT/METIS thermal infrared instrument.