Shortly after celebrating the tenth anniversary of its time in service, engineers have declared the Envisat satellite lost, following numerous attempts to re-establish contact since April 8th.

 Despite continuous commands sent from a widespread network of ground stations, there has been no reaction yet from the satellite. There were no signs of degradation before the loss of contact so the team has been collecting other information from ground radar and the French Pleiades satellite. Given what they know, they outlined possible failure scenarios. One is the loss of the power regulator, blocking telemetry and telecommands.  Another scenario is a short circuit, triggering a ‘safe mode’ – a special mode ensuring Envisat’s survival. A second anomaly may have occurred during the transition to safe mode, leaving the satellite in an intermediate and unknown condition. 

Chances of recovering Envisat are extremely low but the investigation team will continue attempts to re-establish contact for the next two months.


Envisat’s Advanced Synthetic Aperture Radar (ASAR) captured this image on 8 April 2012 at 11:09 GMT. The image was transmitted in X-band to the Santa Maria station in the Azores, Portugal, operated by Edisoft. It shows Spain’s Canary Islands. It is the last Envisat data transmitted via X-band before the communication anomaly.  Credits: ESA/Edisoft

While engineers had been optimistic Envisat might last until the launch of the follow-on Sentinel missions, it has already operated for double its planned lifetime.  Envisat's ten sensors observed and monitored Earth’s land, atmosphere, oceans and ice caps, delivering over a thousand terabytes of data. An estimated 2,500 scientific publications so far have been based on this information.  Together with other satellites, it monitored the global sea-level height and regional variations, as well as global sea-surface temperatures with a precision of a few tenths of a degree. 



 Years of Envisat data have led to a better understanding of ocean currents and chlorophyll concentrations.  In the atmosphere, the satellite observed air pollution increase in Asia and its stability in Europe and North America, and measured carbon dioxide and methane concentrations. Envisat also monitored the Antarctica ozone hole variations. Over land, it mapped the speed of ice streams in Antarctica and Greenland. Its images were used regularly to update the global maps of land use, including the effects of deforestation. 

 Using its imaging radar, Envisat mapped ground displacements triggered by earthquakes and volcanic eruptions, improving understanding of tectonics and volcanic mechanisms and providing Earth observation data not only to scientists, but also to many operational services, such as monitoring floods and oil spills. Its data were used for supporting civil protection authorities in managing natural and man-made disasters. 

Well done, little guy.