News

As previously reported (see our <link http: www.aviso.oceanobs.com en news-storage _top external-link-new-window>news), the Jason-2 spacecraft entered again in safe mode on 30 March 2013 at approximately 22:31:56z.  

Jason-2 went to safe hold mode outside a CDAS/USG fly-by, outside South Atlantic Anomaly and the failure caused an automatic switch to the redundant payload module (PM-B). Then Jason-2 converged to nominal 'BBQ' mode. As for the previous occurrence no on board alarms can be seen in the telemetry.

On Tuesday April 2nd, CNES and Thales Alenia Space (TAS) experts discussed several options for the anomaly; this exercice is very difficult because we face a lack of information and we are unable to identify clearly a root cause. Due to the experience on Jason-1 (a lot of memory troubles due to the aging on this agressive orbit), the most probable scenario (not yet confirmed) is an anomaly in the memory detected by the on board software and causing the reconfiguration. An action plan is currently defined with TAS and a progress status is expected by the next REVEX.

To date other diagnostics of the spacecraft did not detect any trouble in the sub-systems. Even if the current  failure appeared again on PM-A, it remains usable as platform redundancy. Nevertheless, for the mission, it has been decided this time to resume it on platform module B. This is the only change wrt the previous recovery done last week and we hope it will be successful.

 The requested platform recovery operations for resuming the nominal mission have started Tuesday April 2nd and are now well underway with gyros, star trackers and reaction wheels switched ON. DORIS instrument is also operational since 17:27z. The OPS teams from CNES and NOAA are working closely to conduct operations and to monitor the spacecraft carefully.

The recovery procedure has been optimized and the current schedule foresee to turn on the Jason-2 payload core science instruments (POSEIDON3, AMR, GPSP) on Friday, 5 April, and full science operations will resume later that day. Jason-2 passengers (LPT, CARMEN2, T2L2) will be turned on on Monday, 8 April. 

Of course this schedule is optimistic… there is no margin and it does not take into account any unexpected event! 

Cycles 174 and Cycle 175 (which begun on 02 April at 09:03z) will be impacted. 

We'll keep you informed on the status in the next days,

Thierry Guinle
on behalf EUMETSAT-NOAA-CNES-JPL Project Managers

See related previous events:

• 2013/04/02 [Jason-2]<link http: www.aviso.oceanobs.com en news-storage _top external-link-new-window> new Safe Hold Mode
• 2013/03/29 [Jason-2] <link http: www.aviso.oceanobs.com en news-storage _top external-link-new-window>Restart of core mission
• 2013/03/28 [Jason-2] <link http: www.aviso.oceanobs.com en news-storage _top external-link-new-window>Start of recovery
• 2013/03/26 [Jason-2] <link http: www.aviso.oceanobs.com en news-storage _top external-link-new-window>Jason-2 in Safe Hold Mode since March 25th 03:30 UTC