Sentinel-6 Michael Freilich becomes the new Reference Altimetry Mission for the worldwide altimetry satellites constellation, Jason-3 will start its repositioning maneuvers tomorrow, Thursday, April 7th

As indicated during the last OSTST meeting, and in coherence with the OSTST recommendation and the CEOS OST-VC declaration on March 24th, 2022, stating that Sentinel-6 Michael Freilich becomes the new Reference Altimetry Mission for the worldwide altimetry satellites constellation, Jason-3 will start its repositioning maneuvers tomorrow, Thursday, April 7th, at the very beginning of cycle 227.

First, the Poseidon core instrument will be commanded to WAIT mode at 13:36z, stopping the scientific telemetry availability until the repositioning maneuvers are complete.

Two 5km SMA increasing maneuvers will then be executed at 19:42z and 22:30z. They will be followed by two additional positive thrusts on April 11th, and a drift period until April 17th, when lowering maneuvers will start.

The objective of these maneuvers is to reach on April 25th an orbit enabling an interlaced grid with the S6-MF reference, and a separation of approximately 5 days with S6-MF for the measurements, thus doubling the measurement capacity on the reference orbit.

Once those maneuvers are achieved, Poseidon will be restarted, and the mission will be fully operational, with a cycle number reset to 300.

Due to the uncertainties on the maneuvers, the exact date and time of the restart is still unknown, and should happen at the beginning of the week of April 25th. We will of course keep you updated on the exact time and date of the restart as soon as they are known.

Jason-3 remains available for a future tandem phase with Sentinel-6 MF, in order to monitor the potential drifts, and wishes to S6-MF a long and successful life as the Reference Altimetric Mission.

Christophe Marechal / CNES JASON-3 project manager, on behalf 4P project managers, at EUMETSAT, NOAA, and JPL.