Farewell, Silent Philae

Artist’s impression of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko. Image Credit:  ESA–J. Huart, 2013

Artist’s impression of the Rosetta orbiter deploying the Philae lander to comet 67P/Churyumov–Gerasimenko.
Image Credit: ESA–J. Huart, 2013

August 3, 2016 – Communication between the Rosetta spacecraft and the Philae Lander was terminated on July 27, 2016. Switching off the Electrical Support System Processor (ESS) is part of the preparation for Rosetta’s end of mission.

The spacecraft is some 520 million km from the Sun and suffering a significant loss of power – about 4W per day. In order to continue scientific operations over the next two months and to maximise their return, it is necessary to start reducing the power consumed by non-essential payload components on board.

No signal has been received by Rosetta from Philae since July 9, 2015, and earlier this year the lander was considered to be in a state of eternal hibernation. In spite of this, the ESS was kept on until now in the unlikely chance that Philae would re-gain contact. Although Rosetta has reached altitudes well below 10 km over the surface of Comet 67P/Churyumov-Gerasimenko, no additional signal from the lander was received.

The decision to turn off the ESS was made by the mission manager and implemented by the Rosetta Mission Operations Center, in coordination with the DLR Lander Control Center and the Rosetta Science Ground Segment.

Rosetta is set to complete its mission in a controlled descent to the surface of Comet 67P/Churyumov-Gerasimenko on September 30. The final hours of descent will enable Rosetta to make many once-in-a-lifetime measurements, including very-high-resolution imaging, boosting Rosetta’s science return with precious close-up data achievable only through such a unique conclusion.