Rosetta and Philae Go for separation

Credits: ESA/ATG medialab

We are go for separation! Credits: ESA/ATG medialab

Following a night of critical Go/NoGo decisions, Rosetta and Philae are cleared for separation, despite a problem onboard the lander.

During checks on the lander’s health, it was discovered that the active descent system, which provides a thrust to avoid rebound at the moment of touchdown, cannot be activated.

At touchdown, landing gear will absorb the forces of the landing while ice screws in each of the probe’s feet and a harpoon system will lock Philae to the surface. At the same time, the thruster on top of the lander is supposed to push it down to counteract the impulse of the harpoon imparted in the opposite direction.

“The cold gas thruster on top of the lander does not appear to be working so we will have to rely fully on the harpoons at touchdown,”says Stephan Ulamec, Philae Lander Manager at the DLR German Aerospace Center.

“We’ll need some luck not to land on a boulder or a steep slope.”

“There were various problems with the preparation activities overnight but we have decided to ‘go’. Rosetta is lined up for separation,” says Paolo Ferri, ESA’s head of mission operations.

Thus despite the potential problem concerning the moment of touchdown, separation will proceed on the planned timeline.

Separation will occur in space at 08:35 GMT / 09:35 CET, but it will take the radio signals from the transmitter on Rosetta 28 minutes and 20 seconds to reach Earth and be transferred to the Rosetta Mission Control Centre at ESA’s Space Operations Centre in Darmstadt, Germany.

That means we must wait until about 09:03 GMT / 10:03 CET for confirmation the separation has happened correctly.

The Go/No-Go decisions leading up to this milestone began last night at 19:00 GMT / 20:00 CET, with the first confirming that Rosetta is in the correct orbit for delivering Philae to the surface at the required time.

The second Go was given at midnight (GMT), confirming that the commands to control separation and delivery are complete and ready to upload to Rosetta. The Go also confirmed that Rosetta’s overall health is good, and that the orbiter is ready to perform.

At 02:35 GMT / 03:35 CET the third GO was given after a final verification that the lander is ready for touchdown.

The final manoeuvre by Rosetta was conducted at 07:35 GMT / 08:35 CET, which is taking Rosetta to a point about 22.5 km from the comet’s centre for separation.

Labelled trajectory of Rosetta’s orbit, focusing on the manoeuvres on 12 November. Credits: ESA

Rosetta's manoeuvres on 12 November. Credits: ESA

The manoeuvre was followed by the final Go/No-Go decision that verified the two spacecraft, the orbit, the ground stations, the ground systems and the teams are ready for landing.

After separation, we will not hear from Philae for some two hours until the lander establishes a communication link with Rosetta. Philae cannot send its data to Earth directly – only via Rosetta.

The descent to the surface of Comet 67P/Churyumov–Gerasimenko will take around seven hours, so confirmation of a successful touchdown is expected in a one-hour window centred on 17:02 GMT / 18:02 CET.

“We are anxious but excited,” said Jean-Pierre Bibring, lead lander scientist, during this morning’s press briefing. “It is not every day that we try to land on a comet.”

Follow the event live via




  • Jelto Buurman says:

    Good luck!

  • Vincenzo says:

    I think all the times you mentioned are actually shifted by 1h... Manoeuvre took place at 6.30 GMT and touchdown confirmation is expected at roughly 16.00 GMT

  • Cometstalker says:

    With some luck its just a SW bug that blocks the cold gas (He?) valve function. If the valve got stuck it might rattle free at impact.
    Good decision to go on anyway.

    To pray for good luck might help but i will pray that any bad luck is far from the comet. And if landing on cigarett ashes, no worries. How about ashes from cigars? You might light one of those occasional sticks once safely landed and can the experiment with this kind of ash.

  • Johan Zandin says:

    Isn't the touchdown window supposed to start already at 16:02 UTC /17:02 CET?

  • Andreas says:

    All the best for the touchdown. I'm really excited about this mission and will follow the next hours. Today you will make history!

  • Colin Brazier says:

    Good info. How do we find out if pre-delivery manoeuvre is successful?

  • neth says:

    I am watching the live stream. Unfortunately there is no sound!!!!!!!

  • Favio G. Martinez says:

    Felicitaciones a.TODOS!!....Ya el solo hecho de alinear un robot para hacerlo aterrizar encima de in c ometa es una hazaña increible!!! Mucha ..mucha suerte!!! Y para mi en.lo personal ya es un exito la.mision!! Desde uruguay ..como decimos aca... Vamo arriba Carajo!!!!

  • Peter Taylor says:

    From Tasmania: Wishing you all the best luck ! A lot of people watching from Down Under.

  • Scott C says:

    Good luck Rosetta team!!!

  • Carlo Heulens says:

    good luck, we are watching you!
    veel geluk met de landing, hopelijk lukt het. wij volgen het nieuws!

  • Gavin Green says:

    Good luck ESA and Rosetta!

  • mjburgess says:

    lets hope that all goes well for Philae and that its epic leap on a comet is rewarded with a smooth landing and no bounces.

  • mjburgess says:

    lets hope that all goes well for Philae and that its epic leap onto a comet is rewarded with a smooth landing and no bounces.

  • Gerry Griffin says:

    WOW !!!!

  • Serdar Öner says:

    Good luck all crew.

  • mikrus says:

    I hope the thruster will start during the landing moment

  • Madis Rumming says:

    Lets go, where no man has gone before.

  • Tim Hewitt says:

    A very exciting day - hopefully the landing will be smooth, even without the active descent system!

  • sid G. says:

    My wish is an axceptable success for people, who worked years on this project! Good Luck!

  • Good luck for the touchdown, we will be "watching" and wishing you well!

  • Pato says:

    I'm totally sure that every thing will be ok in this amazing mission...good luck!

  • Lorand Lukacs jr says:

    This project has had its troubles from the start, but solutions was found to solve them. It even seemsthat a more interesting comet was chosen and more interesting results will be ashieved.
    Hopefully the cold gas driven engine failure may be solved by warming up the gas or nozzle during the descent. If not, the low velocity and the opposite movement of the two bodies along with the harpoons will not create a big repelling force, and the harpoons will get a good grip into the surface layer.
    If the surface layer is SOFT, it may even be an easier touchdown and holding.

  • Darren Gedye says:

    Good Luck from New Zealand

  • Dinah Spyrou says:


  • Gabor G. Mandy says:

    Very exciting indeed. If the touchdown is successful, this will be the first real step in the defense of the Earth against threats from the unknown space.

  • Moritz Schilling says:

    A very exciting day for space exploration scientists. I wish everyone involved fast thinking and good nerves and structural and functional integrity for philae especially.
    Thanks for the good work!

  • Sarah and Ken, Melbourne, Australia says:

    Hope all goes smoothly for the descent after the team's many years of hard work.

  • Marco says:

    GERONIMO !!!

  • Saglio says:

    Thrilling !

  • Gordon Riley says:

    This is the stuff of childhood dreams, of stories one would write in the English language classroom. After years of preparation and then more years of waiting to have your 'baby' reawaken and now part of it begin to take it's first steps unaided is truly breathtaking. I wish you all the success that this project deserves when it comes to landing and stabalising , then ultimately working with materials from the dawn of time.

  • Joker says:

    Good luck Rosetta!!! After first man on the moon this is another epic moment !!

  • Renato says:

    Go PHILAE, GO!
    Thank you guy, today 100 chiedo at primari schifo heroes in Borgaretto (italy) se following you Rosetta and PHILAE: you are inspiring the next generation of Explorer!

  • Renato says:

    Ugly Auto corrector: i meant "100 childs at primary school in Borgaretto..."

  • Nick James says:

    Reminds me of July 1969! Stunning achievements.

  • Mehmet KARAKAS - Turkey says:

    What a very good luck for all of us to watch history live .

  • Martin Kma says:

    That is great moment, you just need to learn how to engage taxpayers to get more money for your projects. Where is the live video to make it spectacular. Do we still just hear beeps like from Sputnik.

  • Seweryn says:

    Good Luck! Have you give me link to the live transmision?

  • Clayton Green says:

    Good luck little fella!!

  • Howie H says:

    From Canada. Extraordinary achievement! All the best to the crew that made this happen. Go Philae!

  • Kiran says:

    Good luck from India

  • ROMAS says:

    Good luck from Lithuania! Sekmingo ir minksto nusileidimo!!!

  • Harimohan says:

    Good Luck from Bangalore, India for the safe landing. We are watching

  • Derek says:

    Good luck from Ireland!

  • Ratko says:

    Good luck from Croatia!! Go go go! 🙂

  • Flavio says:

    Good luck and many thanks for this exciting space adventure!

  • GEKO says:

    Buona Fortuna!

  • PIPICCA says:

    I don't know if exists a typical expression to wish good luck in these kind of expeditions, but between the sailors we say: IN CULO ALLA BALENA, PHILAE!!!!

  • Gavox says:

    I wish you all the best to you "Philae" and your Great team. I feel that you will touch and smell ash and then stay there.

    Be on Time and Make Europe Happy

  • Patti says:

    Good Luck from Lawrence, Kansas! The heartland of America is watching!

  • Gfunk says:

    Should be sleeping here in Sydney but too excited ... all the best from Australia team!

  • Marco says:

    We all are waiting looking to the sky, full of hope and dreams !
    Thank you all !

  • all the best of luck says:

    Its challenging getting the craft into orbit. Now going to land on a moving object without crashing head on into it. All the best of luck. We await good news and new discoveries since our little step on the moon.

  • Carlos Santoro says:

    Good luck to Philae.

  • ROMAS says:

    Su nekantrumu laukiu foto iš nusileidimo vietos.

  • ROMAS says:

    I'm looking forward to the photo of the landing site (Lithuania)

  • I love your space ship , how can I work with it?

Comments are closed.