Towards the definition of flight operation procedures for the ARIEL Instrument Control Unit

ARIEL, ESA’s M4 mission launching in 2031, aims to chemically characterise about one thousand exoplanet atmospheres through low-resolution transit spectroscopy using the AIRS (ARIEL IR Spectrometer) and the Fine Guidance Sensor (FGS). Within this context, dedicated Flight Operations Procedures (FOPs) are being developed for the Instrument Control Unit (ICU), which controls AIRS and the Telescope Control Unit (TCU). These structured and traceable procedures support instrument operations from integration and verification to in-flight use. Their development builds on the Full Functional Tests (FFTs), a set of TCL scripts used to verify requirements. The methodology identifies atomic scripts as building blocks for the FOPs, later converted into procedure-management formats for the final implementation of the needed services in the ICU Application Software, including those needed for the FDIR (Fault Detection, Isolation and Recovery).