How we heard from Philae

Saturday, 13 June 2015

22:28 CEST on board Rosetta: The orbiter’s Electrical Support System Processor Unit (ESS) starts receiving radio signals from Philae, approximately 200km beneath Rosetta on the surface of Comet 67P/Churyumov-Gerasimenko.

22:28 CEST on board Rosetta: Spacecraft immediately starts relaying Philae data to Earth via NASA’s 70m deep-space antenna at Goldstone, California. One-way light time is 16.8 minutes, so signals start arriving at about 22:45 CEST on Earth and are immediately relayed to ESOC, Darmstadt, Germany.

Transmitting to the experts back home Credit: ESA

Transmitting to the experts back home Credit: ESA

Just after 22:45 CEST in Planetary Missions Dedicated Control Room, ESOC: Achim Zschaege, the on-duty spacecraft controller watching telemetry downloading from Rosetta, notices some alarms that had been specially set on some Lander ESS parameters. These had been implemented shortly after separation (in November 2014) to ensure any Lander contact would not be missed. After confirming this was, indeed, correct, and that lander telemetry were being received, he consults an ‘Action Sheet’ kept on hand since 15 November 2014 (when Philae entered hibernation on the comet) to determine what to do.

23:00 CEST ESOC: As defined on the ‘Action Sheet’, the Achim telephones the Rosetta on-call spacecraft operations engineer, Jake Urbanek, at his home near Darmstadt. He reports the news.

23:30 CEST at Jake’s home: Jake calls Rosetta Spacecraft Operations Engineer Armelle Hubault at her home to confirm that the Lander had switched on and transmitted telemetry.

23:45 CEST at Armelle’s home: Armelle confirms the news by calling the Lander Team on a pre-agreed phone number. Lander team confirms Lander is back! Armelle also rings Sylvain Lodiot, the Rosetta Spacecraft Operations Manager, who then rings Paolo Ferri, ESA’s Head of Mission Operations. Paolo subsequently relays the information to the rest of the Rosetta science and operations managers.

Armelle reports: “I had just brushed my teeth and was heading to bed when the phone rang. Seeing Jake was calling, I picked up the phone and said: ‘This has to be bad news. We’ve got a safe mode, don’t we?’ ”

“He replied: ‘Well, maybe not. Maybe it’s good news!’ And, yes, it was.”

Editor’s note: After this weekend’s news, the Rosetta Flight Control Team today have switched into high gear, with a great deal of coordination work now being carried out with the flight dynamics experts at ESOC as well as with the Rosetta Science Ground Segment (RSGS/ESAC), the Philae Lander Control Centre team (DLR Cologne) and the lander science operations centre (SONC), at CNES/Toulouse. We’ll post updates here as we get them.

Listen to the audible control room alarm used at ESOC for Rosetta:



  • Margarita says:

    Thanks for the details, Daniel. I really appreciate how you in the public relations team keep us “in the loop”.

  • McKienley says:

    Hi Daniel
    Ty for sharing this story with us.

    Will there be an ESA-Hangout anytime soon ?

    Would be realy nice to see the Team and get some details.

  • Margarita says:

    I’ve just seen a tweet from Philae (17:59 here in Tenerife) that gives a link to DLR.
    I don’t know if hyperlinks are permitted in comments, but here it is
    “The data acquired during the second contact confirms that Philae, which is on the surface of Comet 67P/Churyumov-Gerasimenko, is in good condition and ready for operations. Now, the trajectories of the Rosetta orbiter will need to be adapted to allow longer contact times with Philae.

    There is now sufficient energy and a temperature that is not so low, so Philae is currently receiving at least three hours of sunlight per comet day, which supplies it with energy. Until now, the engineers had been expecting only 1.3 hours of illumination. ”

    I think DLR need input from Daniel, Emily and Claudia 😉 – the title “Nocturnal contact with Philae” is slightly under emphatic! But that doesn’t matter (and I’m joking anyway): the news is superb.

  • André H says:

    And what was the name of the on-duty spacecraft controller? Who actually was at work and not on telephone assistance.

    • Vincent Pinto says:

      That’s right; we’d like to know the name of this person too! This in no way would diminish the joy of the other off-duty controllers, whose name we would have requested instead had Philae said “Hi” during his/her watch 🙂

    • IWG says:

      Yes, I’d wondered that too! 🙂

    • Margarita says:

      Yes! I agree – thanks for thinking if this, André! There if a photo here ( of where the messages are received and a photo – by Daniel I think? – of one of the staff members. But NO names!

      It’s like the ship’s boy being on look out on the Crows’ Nest and espying the long dreamt off land fall! C’mon, you guys, give us a name and a photo… Pretty Please!

      • Margarita says:

        Oops – excuse typos! I’m writing this on a Tablet whilst lying down! Just about to have my siesta….

  • andrew says:

    i am very glad that it has woken up now you will be able to get some pictures of were it is.

  • Gaelle says:

    Thank you for sharing the story ! We look forward to hearing from rosetta & investigation Partner Philae (should I say sleeping beauty)

  • Jean-Pierre Urbain says:

    On a fait ça, nous les humains! Soif de connaître, de comprendre, d’expliquer. Magnifique exemple de ce que l’on peut réalisée par la coopération, cette fois à l’échelle européenne.

  • Pierre says:

    Thanks for taking the time to tell us all this. We really appreciate !!

  • Would it be possible to determine “optimal” signal duration and timing for Philae to send a stream of signals to Rosetta and then compare the absence of some of these signals with the “faces” of the comet being presented to Rosetta. Thus the times of the lander’s absent or weakened signals could be plotted against the portions of the comet that weren’t facing Rosetta. This might allow Philae to be more easily located? As Ever, Orin Keplinger, near Chicago E) 🙂

  • Rod says:

    As Margarita said, “keeping us in the loop”
    outsiders like myself really appreciate you guys sharing with us the little details of this fantastic project .
    For me, I am 65 and am thrilled to witness such a major and wonderful achievement in space exploration

  • James says:

    This is such great and exciting news! Yay! I felt such despair when the lander went into hibernation and was in disbelief but exhilarated when I read this good news in far-off New York! Keep going and congratulations on this most magnificent and ambitious mission! We’re all watching and rooting for you and Philae and Rosetta.

  • Vincent Pinto says:

    Please keep us in the loop, even if you dont plan to do anything for the next few hours for whatever technical reason (as one said it in a different thread on this blog). This is cutting-edge technical delight going on! Recall how our hearts sank into our stomachs in Nov, alongside your own. And now while your joy is increased greatly, please videorecord short comments of the various folks at DLR, ESOC, etc, and post. We love to share in your joy! We’ll wait for the press and public presentations later.

  • Alexandr Krutov says:

    Мои поздравления!
    Вы молодцы!

    • Margarita says:

      Hey! That’s nice, Alexandr. And I’ve learned Russian for “you rock!”;-)
      Alexandr wrote:
      “My congratulations!
      You rock!”

      I agree!

  • Massimo says:

    Would it be possibile to explain in simple words/steps how Philae get “restarted” and what it does first post hybernstion?

  • Romuald says:

    This is just great! Congratulations team, I always believed, that Philae is not lost and will come back like Lazarus 🙂

  • Kamal Lodaya says:

    Daniel: From the next post it looks like Rosetta was at the zenith above Philae when contact occurred. Can we calculate when this happened before 13 June? Then perhaps we can have confirmation that Philae was not awake then.

  • ralph wood says:

    Superb news. Such good work in a sea of bad happenings on earth. Would love to know how the software was written to have survived so many setbacks. The 24 watts is the aproximate max. energy arriving. Why isn’t the battery charging?
    Please, please take care now!
    fingers and toes all crossed…

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