November 15, 2014
Rosetta’s lander has completed its primary science mission after nearly 57 hours on Comet 67P/Churyumov–Gerasimenko.
After being out of communication visibility with the lander since 09:58 GMT / 10:58 CET on Friday, Rosetta regained contact with Philae at 22:19 GMT /23:19 CET last night. The signal was initially intermittent, but quickly stabilised and remained very good until 00:36 GMT / 01:36 CET this morning.
In that time, the lander returned all of its housekeeping data, as well as science data from the targeted instruments, including ROLIS, COSAC, Ptolemy, SD2 and CONSERT. This completed the measurements planned for the final block of experiments on the surface.Philae’s first bounce as seen by Rosetta.
In addition, the lander’s body was lifted by about 4 cm and rotated about 35° in an attempt to receive more solar energy. But as the last science data fed back to Earth, Philae’s power rapidly depleted.
“It has been a huge success, the whole team is delighted,” said Stephan Ulamec, lander manager at the DLR German Aerospace Agency, who monitored Philae’s progress from ESA’s Space Operations Centre in Darmstadt, Germany, this week.
“Despite the unplanned series of three touchdowns, all of our instruments could be operated and now it’s time to see what we’ve got.”
Against the odds – with no downwards thruster and with the automated harpoon system not having worked – Philae bounced twice after its first touchdown on the comet, coming to rest in the shadow of a cliff on Wednesday 12 November at 17:32 GMT (comet time – it takes over 28 minutes for the signal to reach Earth, via Rosetta).