Category: Operational news

Envisat will bring to a new lower orbit to ensure an additional 3 years lifespan. During this period of manoeuvres (22 Oct - 2 Nov 2010), the Envisat data flow will be suspended and no data from Envisat will be processed in Duacs in Near Real-Time.

On the 22 October 2010 (at the beginning of the cycle 94), the Envisat altitude will be reduced by 17.4 km in order to free the current orbit for other Earth observation missions. On the other hand in order to reduce the fuel consumption during orbit maintenance and therefore prolong the Envisat life, the satellite inclination control will be stopped which will cause a slow change of inclination.
The consequences for the Duacs Near Real-Time users are the following:

1. The Envisat data flow will be suspended during the period 22 October to 2nd November 2010. Note that ESA could decide to extend this period of unavailablility if necessary.
2. The ground track will change and consequently the repeat cycle will change: 30 days with 431 orbits per cycle instead of 35 days-501 orbits per cycle. The Sea Level Anomalies will now be produced using a MSS, which will slightly degrade the data performances. Note that to limit the degradation of the SLA performances a recent MSS model will be used (CNES_CLS_10 model) to produce the along track Envisat data. As the new orbit will not be strictly repetitive the MSS will certainly be used until the end of the mission for the SLA production.
3. The nomenclature of the products will change: "EN" will be change in "ENN" in the file names.

Further information:

• <link http: envisat.esa.int earth www object _blank external-link-new-window>Envisat on the Esa's website.