[meteorite-list] Philae Lander Fails to Respond to Last-Ditch Efforts to Wake It

[Ron Baalke]

https://www.newscientist.com/article/dn28752-philae-lander-fails-to-respond-to-last-ditch-efforts-to-wake-it/

Philae lander fails to respond to last-ditch efforts to wake it
New Scientist
By Jacob Aron
11 January 2016

Farewell, Philae. The space lander that touched down on comet 67P/Churyumov-Gerasimenko 
(and in our hearts) in November 2014 has not responded to a last-ditch 
attempt to wake it, and it now looks almost certain that the lander is 
permanently sleeping.

Comet 67P is moving away from the sun, and in just a few weeks will become 
too cold and dim for the lander to survive. It has not been heard from 
since July 2015. Last night, mission managers at the German Aerospace 
Center in Cologne sent a signal to Philae commanding it to spin its internal 
flywheel, a risky and unpredictable manoeuvre that could dislodge it from 
its shady landing spot in the hope of getting more sunlight on its solar 
panels. It didn't work.

"We did not hear anything," says lander manager Stephan Ulamec. In the 
best-case scenario, Philae may have received the command and moved, but 
be unable to respond due to a damaged transmitter. It is more likely that 
the signal was not received.

In mourning

The team will try a few more commands, but it looks like Philae has officially 
gone. "We have to face reality, and chances get less and less every day 
as we are getting farther and farther away from the sun," says Ulamec. 
'At some point we have to accept we will not get signals from Philae anymore."

Philae's orbiting companion Rosetta has scanned the landing zone with 
its camera. Ulamec's team will scour the images for any sign of a dust 
cloud thrown up by the lander moving, but Rosetta is far away from the 
comet and Philae is too small to be seen directly.

Besides mourning the loss of the most famous space probe of recent times, 
the team is also disappointed that Philae may have more data about 67P 
stored in its memory that will now be lost. 'It's certainly a bit sad 
that we could not retrieve more data after the wake-up in June," says 
Ulamec. 'We have to live with the data that we got in November 2014."

There remains one small hope. As Rosetta comes to the end of its mission 
in September this year, mission managers are planning to bring it down 
into a very low orbit of the comet, eventually touching down on the surface 
itself. Rosetta should be able to capture close-ups of Philae's final 
resting spot, giving us one last look at the probe. "You should clearly 
see the lander, and this will help us interpret the data we received in 
November," says Ulamec.