FORUM (Earth Explorer 9)

FORUM [Airbus Defence and Space]

ESA’s Earth Observation Programme Board has selected FORUM (Far-infrared Outgoing Radiation Understanding and Monitoring) to become the ninth Earth Explorer mission. FORUM will be the first satellite to observe Earth in the far-infrared part of the spectrum, providing unique measurements of the Earth’s outgoing energy to help improve understanding of the climate system.

Measurements from FORUM’s spectrometer will enable scientists to compile a high resolution view of the Earth’s greenhouse effect and the properties of ice clouds and water vapour in the atmosphere. Airbus is mission prime with OHB providing the instrument.

The main instrument on FORUM will be a Fourier Transform Spectrometer operating in the far-infrared. The Sun’s incoming shortwave radiation is absorbed at the Earth’s surface and re-emitted into space, through the atmosphere, at longer infrared wavelengths. FORUM will measure the signature of this outgoing radiation, from which a crucial understanding of water vapour, ice clouds, surface snow and ice, carbon dioxide and other greenhouse gas characteristics can be derived. The satellite will also be equipped with a thermal imager for ground sample validation.

The FORUM satellite will fly in a loose formation ahead of the MetOp-SG A1 satellite for synergistic observations using MetOp-SG A1’s infrared atmospheric sounding interferometer. Using MetOp’s data at shorter infrared wavelengths will complement and further improve FORUM’s own science.

The planned launch date for the FORUM mission is in 2027 on a Vega-C.