ho ricevuto questa news, peccato perdere così un satellite utile alla causa

> Oggetto: Goodbye Envisat ... and thank you
> > Dear ESA data users,> > Just weeks after celebrating its tenth year in orbit, communication with the> Envisat satellite was suddenly lost on 8 April. A team of engineers has spent> the last month attempting to regain control of Envisat, investigating possible> reasons for the problem. Despite continuous commands sent from a widespread> network of ground stations, there has been no reaction yet from the satellite.> > The team has been collecting other information to help understand the> satellite's condition. These include images from ground radar and the> French Pleiades satellite. With this information, the team has gradually> elaborated possible failure scenarios. One is the loss of the power regulator,> blocking irreversibly telemetry and telecommands. Another scenario is a short> circuit, triggering a 'safe mode' - a special mode ensuring> Envisat's survival. A subsequent anomaly may have occurred during the> transition to safe mode, leaving the satellite in an intermediate and unknown> condition. The investigation team's assessment is that the chances of> recovering Envisat are extremely low.> > Therefore the end of the Envisat satellite operations is being declared. The> investigation team will nevertheless continue attempts to re-establish contact> while considering failure scenarios for the next two months.> > The outstanding performance of Envisat over the last decade led many to> believe that it would be active for years to come, at least until the launch> of the follow-on Sentinel missions. However, Envisat had already operated for> double its planned lifetime, making it well overdue for retirement. > > With ten sophisticated sensors, Envisat has observed and monitored Earth's> land, atmosphere, oceans and ice caps during its ten-year lifetime, delivering> over a thousand terabytes of data. An estimated 2500 scientific publications> so far have been based on this information, furthering our knowledge of the> planet. Envisat provided crucial Earth observation data not only to> scientists, but also to many environmental services, such as monitoring floods> and oil spills.> > Now with the end of Envisat's mission, the launch of the upcoming GMES> Sentinel satellites has become even more urgent to ensure the continuity of> data to users, improve the management of the environment, understand and> mitigate the effects of climate change and ensure civil security.> > See also Press Release on the ESA Portal at> ESA Portal - ESA declares end of mission for Envisat> > > Kind regards> > EOHelp on behalf of the Envisat Mission Manager> > ************************************************************ *****> The ESA Earth Observation Missions Helpdesk Team> Email: eohelp@esa.int> Web Site: http://earth.esa.int/> Fax: 0039 06 94180-292> Telephone: 0039 06 94180-777> Postal Mail: ESA ESRIN > Via Galileo Galilei, I-00044 Frascati Italy > ************************************************************ *****

in soldoni gli ingegneri addetti al controllo hanno perso il segnale da un mese e hanno stimano possibili scenari di problemi avutisi da far perdere il segnale. comunque è campato il doppio del tempo previsto per cui direi che ci può stare.