The SCIAMACHY Extended Mission

The Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) on-board the European EO platform ENVISAT has successfully achieved its nominal mission lifetime and is now in its first phase of mission extension until 2010. Because of the excellent status of the platform and the majority of instruments a further extension until the year 2013/2014 timeframe is in preparation. This more than doubles the originally specified in-orbit operations phase of SCIAMACHY and provides for a long continuous set of nadir and limb data. The second phase of the extension will be accomplished by modifying the ENVISAT orbit without maintaining fuel consuming inclination manoeuvres. Since SCIAMACHY’s viewing geometries are orbit dependent, reconfiguration of the instrument is required to further maintain the high quality of the acquired data. Additionally instrument subsystems are expected to degrade in orbit. These effects have to be compensated for by changing in-orbit operations and monitoring procedures as well as on-ground retrieval algorithms. We describe the expected instrument status at the start of the second extension phase in 2010 and what can be predicted for the end of the mission in about 2013/2014. Both degradation and orbit modification topics are addressed. It is shown how SCIAMACHY prepares for additional several years in-orbit thus serving the atmospheric science community with a wealth of high quality measurement data