Contact lost with big satellite

Contact has been lost with the European Space Agency\'s (Esa) flagship Earth observation mission - Envisat. Controllers stopped receiving data from the eight-tonne spacecraft on Sunday, and have not as yet been able to re-establish communications. Envisat was launched in 2002 and is already operating five years beyond its planned mission lifetime. Esa was expecting to turn off the spacecraft in 2014, once the first in a series of follow-ons had been launched. A recovery team, which includes experts from industry, is now working to try to re-establish contact with the platform. It is not uncommon for communications with a satellite to be lost from time to time, and controllers will be encouraged that the spacecraft appears to be in a stable condition as it moves around the globe from pole to pole. Envisat has been at the forefront of European Earth observation endeavours for a decade. It carries 10 sophisticated instruments to monitor the land, the oceans, Earth\'s ice cover and its atmosphere. The mission is due to be replaced by the Sentinel series of satellites. The first of these - Sentinel 1 - is supposed to take over the radar duties of Envisat when it is launched next year. Scientists had hoped to have the pair operating in orbit together for a period of time so they could cross-calibrate their data. Once that was done, it was expected that Envisat, which costs some 40 million euros a year to run, would then be retired.