EE-11 candidate mission CAIRT: an overview of the Phase 0 and A System studies

The Changing-Atmosphere Infra-Red Tomography (CAIRT) mission was proposed as ESA’s Earth Explorer 11 candidate to address critical gaps in understanding the middle atmosphere and its role in climate forcing and feedbacks. Using an innovative imaging Fourier Transform Spectrometer, CAIRT combines limb sounding with high-resolution infrared spectroscopy to deliver unprecedented 3D observations of atmospheric composition, temperature, aerosols, and optically thin clouds. These measurements are needed to improve understanding of processes such as gravity wave dynamics, tracer transport, and long-term circulation trends.
This paper provides an overview of the mission’s scientific objectives, the observation concept, and key technical requirements, followed by a detailed account of the system architecture developed during the Phase 0 and Phase A studies.
Two payload concepts were defined and matured, sharing the same measurement technique but differing in implementation details. Extensive pre-development activities were conducted to de-risk critical subsystems including the interferometer, detector assemblies, cryogenic cooling, and pointing mechanisms. ... mehrAt the end of Phase A, the mission was deemed to have reached the required scientific and technical readiness level and demonstrated strong scientific relevance.