Philae status report: “Time is running out”

This text is based on the report published today by the German Aerospace Center, DLR.

Rosetta’s lander Philae has remained silent since 9 July 2015. With every passing day, Comet 67P/Churyumov-Gerasimenko is getting further and further away from the Sun, and as such, temperatures are falling on the comet's surface. Things are getting critical for Philae: conditions are predicted to be “lander-hostile” – too cold – by the end of January.

But the lander team are going to try another method to trigger a reponse from Philae: on 10 January they will send a command, via Rosetta, to attempt to make Philae’s momentum wheel switch on.

"Time is running out, so we want to explore all possibilities," says Stephan Ulamec, Philae lander manager at DLR.

Philae’s momentum wheel ensured that it was stable during its descent from the orbiter on 12 November, 2014.

If the command is successfully received and executed, the hope is that it might shift the lander’s position.

"At best, the spacecraft might shake dust from its solar panels and better align itself with the Sun," explains Philae technical manager Koen Geurts at DLR’s lander control centre.

But it is also possible that the lander may not be able to respond to the command. It remains unclear as to what state Philae is in since it last sent data about its health in July, but the DLR team believes that one of the lander’s two transmitters and one of the two receivers have failed. The second transmitter and receiver apparently no longer function smoothly, either.

The team continues to hope that Philae has not tilted over or become covered with too much dust. On an active comet, which is ejecting gas and dust into space, the lander is not in a particularly safe location.

"Unfortunately, Philae's silence does not bode well," says Stephan.

In the night of 21-22 December, 2015, the receiver on Rosetta was triggered, but analysis showed that this was not a transmission from the lander.

By the end of January, 67P/Churyumov-Gerasimenko will be more than 300 million kilometres from the Sun, resulting in an operating temperature of less than -51ºC on Philae such that the lander will no longer be able to turn on.

The command to activate the spin wheel will, therefore, be one of the last attempts to obtain a response from the lander.

"There is a small chance," says Philae operations manager Cinzia Fantinati from DLR’s control team. "We want to leave no stone unturned."

The communication unit on Rosetta will still remain switched on and continue listening for Philae beyond January.

Rosetta’s mission will continue until the end of September 2016.

Rosetta is an ESA mission with contributions from its Member States and NASA. Rosetta's Philae lander is contributed by a consortium under the leadership of DLR, MPS, CNES and ASI.




  • Marcin says:

    I imagine it must be really frustrating for the instrument teams. So close yet so far. I know I would be really annoyed. Wish you best luck guys!

  • Paul Badertscher says:

    Thank you for the update. Good luck! Do you know what triggered the receiver on Rosetta in December?

    • Pep de Rooij says:

      I was wondering the same thing.

      I hope you guys manage to make contact with Philae!

  • Thomas canning says:

    Will Rosetta try any nearer fly-bys before the end of January to try and locate Philae accurately as well as try communication from a closer distance?

  • Me says:

    The comet has extremly low gravity, right? So, if they find out where Philae is, could they Land Rosetta there? I mean, the engine and fuel will probably be fine, sinc there is such a low gravity.

    And if this is genrerally possible, why don't give Phillae a "little bump"? Just a little, so nothing brakes...

    • Harvey says:

      I'm afraid that's impractical.
      Firstly Rosetta would certainly be destroyed; and we need Rosetta to relay Philae's signals, it cannot communicate with earth directly. No way would one sacrifice the rest of the data from Rosetta.
      Secondly we don't know where Philae is with sufficiet accuracy, and could not 'land' Rosetta accurately enough to hit it even if we knew.
      So I'm afraid its a non-strarter.

  • logan says:

    Could be set a way of spin and brake?

  • Sam says:

    Is it possible that Philae has been ejected from the comets surface?

  • Frans van Muijen says:

    I hope philae will get shaken up! Good luck to you all team!

  • Fokeyjojo says:

    Hi.. It's such a shame that the lander hasn't had as much success as it should have. I was thinking that if you get to do it again, maybe it's worth having some mechanism to shine light onto the dark areas? Like one of the solar panels can flip around to be a mirror. Even if it wasn't enough to give the lander energy to start its systems, at least you might have been able to find it and see what its situation was.

  • Guili says:

    I think it's nice to attempt this but in my opinion it's too late and should have been done a long time ago.
    It seems that the team was conservative in its approach and basically hoped that things would solve by thermselves at perihelion.
    I would have taken the risk to move the lander last year, when the receiver and transmitter electronics were not broken by the cold or just after there were proofs that they were failing.

  • Today is 11/1/2016 and I can't find any reports on the outcome of the 10/1/2016 attempt to trigger the lander. Does anyone know the results from the test?

  • emily says:

    Here's an update from the lander team, via @DLR_en:

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