The European Space Agency (ESA) has declared a spacecraft emergency as it is trying to establish why its Envisat satellite has suddenly stopped sending data to Earth after 10 years of service.
Envisat was launched on 1 March 2002. Since then, it has orbited the Earth more than 50,000 times to deliver thousands of images and data to study planet Earth, based on its space observations.
The eight-tonne satellite carries optical and radar sensors that have provided information about our land, oceans, ice and atmosphere, as well as precise measurements on climate change.
The ESA says its mission control is working to re-establish contact with the satellite. The space agency said the first signs that there was a problem with Envisat happened on 8 April, when contact with Envisat became lost unexpectedly, preventing the reception of any data as the satellite passed over the Kiruna ground station in Sweden.
Terming it a spacecraft emergency, the ESA called for support from additional ESA tracking stations around the world.
Operations and flight dynamics specialists and engineers have been since trying to re-connect with the satellite.
An anomaly review board is investigating the cause for the break in communications.
"While it is known that Envisat remains in a stable orbit around Earth, efforts to resume contact with the satellite have, so far, not been successful," said the ESA in an official statement.
The MERIS instrument on Envisat monitored phytoplankton, the base of the marine food chain that plays a huge role in the removal of carbon dioxide from the atmosphere and the production of oxygen in the oceans. Different types and quantities of phytoplankton exhibit different colours. Image by ESA
Envisat itself has been in orbit for 10 years, twice as long as had been intended, but the space agency had been hoping to keep the satellite in service until the launch of its Sentinel missions, starting from next year.
It said more than 4,000 projects in more than 70 countries have been supported with Envisat data to date.
"The interruption of the Envisat service shows that the launch of the GMES Sentinel satellites, which are planned to replace Envisat, becomes urgent," said Volker Liebig, ESA’s director of Earth Observation Programmes.
The first of the new series of Sentinel missions for Europe’s Global Monitoring for Environment and Security programme is planned to launch next year.