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On January 17, 2022, the Jason-3 mission celebrates its 6th anniversary in orbit.

Initially designed to operate between three and five years, the satellite exceeds its specified lifetime by one year, with all its redundancies still available. It has made more than 27,000 revolutions around our blue planet, and recorded measurements of unprecedented accuracy using 180 million radar pulses.

The ocean altimetry technique used by Jason-3 is still the most efficient to measure ocean circulation and its variations, as well as the rise of the mean sea level. However, next April, Jason-3 will hand over to Sentinel-6MF, a Copernicus mission designed on the specifications of the Jason system in order to extend the long series of continuous measurements that began in 1993 with TOPEX/POSEIDON. Jason-3, following Jason-2, remained the world reference mission for ocean altimetry measurements for five years: after a validation phase of the quality of Sentinel-6 products in which CNES actively participated, it was deemed sufficient for Sentinel-6 to take over. Next April, Jason-3 will be re-orbited for a new purpose.

Like its predecessors, Jason-3 has enabled many researchers around the world to study and understand ocean phenomena, which play a fundamental role in the evolution of our planet's climate. For example, it has helped to prove and quantify a rise in the average level of the oceans of 3.51 millimeters per year: a measurement that today is no longer in doubt, and which is crucial for the assessment and management of climate change, whose impact is proving to be catastrophic in certain coastal areas or island systems.

In addition, its ability to deliver data in a very short time (typically less than three hours) allows CNES' European (EUMETSAT) and American (NOAA) meteorological partners to interpret its measurements and incorporate them into their climate forecasting models, especially for hurricanes.

Next April, Jason-3 will remain at its initial altitude but will take an opposite orbital position to Sentinel-6, so as to interweave its measurement grid with the reference, and thus double the global measurement capacity. In a few years, when deemed necessary, Jason-3 will return in formation with Sentinel-6, in order to calibrate very precisely the drifts of the instruments. Given the long duration (more than 30 years) of the sea level series, this verification is indeed crucial.

Thanks to the extreme accuracy of its altimetry, radiometry and orbitography instruments (for example DORIS, a CNES instrument whose accuracy of location of a few millimeters is essential to the system's performance), the JASON family (of which Sentinal-6 is a part) fully justifies the renewal of ocean altimetry solutions, and proudly paves the way for future, highly innovative missions in this field, such as SWOT in 2023.