It is designed to be a successor to the Herschel Space Observatory, covering similar wave bands, and to look into chemical evolution in the universe, black hole horizon radiation, and dark energy investigation.
[3] Spacecraft design documentation and prototyping is currently underway and expected to continue until 2023.
Due to budget cuts in 2019, launch is not expected until 2030.
[4][1] The purpose of this mission is to study the universe in millimeter to far infra-red wavelengths.
The instruments are to be cooled with liquid helium to 4.5K for part of the mission, but sun shields will allow it to continue in a degraded mode once the coolant evaporates.