Europe's Rosetta spacecraft is en route to intercept a comet-- and to make history. In 2014, Rosetta will enter orbit around 67P/Churyumov-Gerasimenko and land a probe on it for a front row seat as the comet heads toward the sun. Many thanks to our NASA colleauges for a cool video! 

The listing of our Top Five entries in the Cool Comet campaign!

Image credit: @Axpere via Twitpic - click for full size

Our sincere thanks to all who took part. Judging was very difficult! The complete listing of submisisons is available via TwapperKeeper or here in the blog.

And the Top Five are... 

GRAND PRIZE WINNER! 

@lilla71

Il simbolo di una bellezza tanto stupefacente quanto fugace che vorresti imprigionare nello spazio e nel tempo

Symbols of a beauty as amazing as fleeting, that you would like to capture in space and time

Top Places - 2nd thru 5th

@JPMajor

Why are comets cool? They're cold as ice, dirty as heck and still think tails are fashionable.

@alessandrocumbo

Rosetta dimostra che le distanze risiedono solo nelle menti ottuse degli uomini, il viaggio è cambiare angolo visivo.

Rosetta shows that distances are only limited by the human mind. Journey enables changing your view angle.

@Axpere

Rare Opportunity (to) See Extraterrestrial (&) Truly Tremendous Article. Entrance to dreamworld is #coolcomet http://twitpic.com/55xh4q

@CometsAhoy

Wondrous marvels, lovely sights / Glowing softly in the night / Bearing ancient molecules / Comets really are so cool / #coolcomet

A listing of all #coolcomet Twitter campaign entries ranked by the judges in the 'Honourable mention' and 'Made us chuckle' categories (note 'very rough' EN translation for any entries not in English).

Access details on the campaign via: Take Part in ESA's Cool Comet Campaign 

Bravo and well done to all those listed below!!!

• @kristin_365
• @Jrmluque
• @M__Lopez
• @BuddyWolly
• @magisstra
• @Johnny_Proxy
• @ELDNAstronomy
• @AngusMcLulz
• @diolor
• @EPenguin
• @cifvts
• @LiiveToWiin

Click on Full story to read Tweets... 

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Rosetta entered hibernation at 16:13 CEST today, the moment that ESA & NASA ground stations in Australia lost the probe's radio signal, as planned. Full article in the main ESA website here: http://www.esa.int/SPECIALS/Operations/SEM38RJ4LOG_0.html

Happiness after final command sent!

In the image below, Rosetta Operations Manager Andrea Accomazzo gestures happily in the Rosetta control room at ESOC today, just moments after the final command was sent to Rosetta to trigger a 31-month hibernation until January 2014.

The Rosetta flight control team here at ESOC now plan to issue the hibernation command at 14:47 CEST; confirmation of successful entry would then come approximately 75 minutes later.

Follow @esaoperations on Twitter for all updates. 

The automated start of Rosetta's spin-up manoeuvre took place as scheduled this morning at 10:00 CEST. In this image, ESA's Paolo Ferri and Gerhard Schwehm stand at right while Roberto Porta and Sylvain Lodiot watch the plot coming in from NASA's DSN station at Canberra, Australia. Team are all rather pleased with progress so far! -- Daniel

A nice little update this morning! Our friend and past ESA blog contributor Bertrand Pinel, from France, sent in this screenshot showing the track of the Rosetta radio signal carrier shortly after the GO/NO-GO decision last night and start of the spacecraft's automated hibernation entry sequence (23:47CEST). Bertrand points out that the start of Rosetta's spin up and the switch off today won't be 'visible' to hsi radio equipment because the probe won't be over Europe when it happens (starting in about 30 minutes).

Bertrand is a keen amateur radio astronomer and always amazes us with what he can achieve with home-made equipment! He's contributed to the Mars Express blog in the past (see pictures of Bertrand and some of his equipment here). Merci, Bertrand...and thanks to ESA's Thomas Ormston on the Mars Express team for passing on the details. -- Daniel 

Quick update from the Rosetta dedicated Control Room this AM: Contact via NASA's 70m deep space station at Canberra has been established - you can see signals arriving from Rosetta on screen in the third photo below. Later today, NASA Goldstone and ESA New Norcia will also come on line, so there is plenty of back up available.

Spacecraft Operations Manager Andrea Accomazzo says that the execution of the on-board sequence to prepare the craft for hibernation is on track! Next big milestone comes just after 10:00 CEST today - start of the spin-up manoeuvre. -- Daniel

 
Spacecraft Operations Manager Andrea Accomazzo (standing) with Rosetta engineers Roberto Porta (L) and Sylvain Lodiot (at console) at ESOC, Darmstadt, monitor signals from Rosetta via NASA's Canberra deep space station.

Clock counts down time to next major on-board event: start of spin-up manoeuvre, due at about 10:00 CEST.

Watching signals from Rosetta as the spacecraft conducts an automated switch-over into final pre-hibernation mode.

An update just in tonight from Spacecraft Operations Manager Andrea Accomazzo in the Rosetta Dedicated Control Room at ESOC.

The 'GO' telecommand, which starts the ball rolling on board Rosetta for final automated sequence for hibernation entry, was sent yesterday evening at 21:47 UTC (23:47 CEST). The team at ESOC saw it execute on board the spacecraft about one hour later, at 00:47 CEST, which confirms satellite is on track for hibernation later today.

Basically, the entire sequence to command entering into hibernation is loaded on board and will start automatically, stopping only to wait for the final (manual) command to complete shut-down, due after 13:00 CEST.

Next big event? The spin up manoeuvre at 10:00 CEST today. -- Daniel

View of Canberra 70m (230 ft.) antenna with flags from the three Deep Space Network sites. The Canberra Deep Space Communication Complex, located outside Canberra, Australia, is one of the three complexes which comprise NASA's Deep Space Network. The other complexes are located in Goldstone, California, and Madrid, Spain. Credit: NASA

DSS 43 is scheduled to contact Rosetta starting at 07:20 CEST on Wednesday, 8 June.

One-way signal time is now 1824 seconds. All times subject to change. Mission operations managed from ESA/ESOC, Darmstadt. Most crucial events highlighted in blue. -- Daniel

Notes:

• AoS - Acquisition of signal
• NNO - New Norcia - ESA/ESTRACK 35m deep space station (DSA 1) Australia
• LoS - Loss of signal
• GDS - Goldstone - NASA/DSN 70m deep space station (DSS 14) California
• CAN - Canberra - NASA/DSN 70m deep space station (DSS 43) Australia
• CEB - Cebreros - ESA/ESTRACK 35m deep space station (DSA 2) Spain
• TTC - Telemetry & Telecommands
• FDIR - Failure Detection Isolation and Recovery
• TM - Telemetry
• HGA - High gain antenna

Real-time feed of Twitter updates with the #coolcomet hashtag updates below... view a full archive of all #coolcomet tweets via TwapperKeeper here.

Do you use Twitter? Are you as intrigued by comets as we are? Then tell us 'Why comets are cool' and you might win a trip to ESA's operations centre in Germany on 15 June to celebrate 25 years of comet exploration.

View all entries via TwapperKeeper here. 

Between now and 9 June, you're invited to tell us, via Twitter, why comets are cool. To take part, simply tweet your entry. It must include the "#coolcomet" hashtag, leaving you a mere 130 characters, so brevity is important.

Your tweet may also include a single URL, or weblink, that links to a 'non-text' submission, such as a picture, image, photo, animation, video, audio file or any other sort of digital content. Maybe you can sing a song about comets, and submit a link to a video of you singing in YouTube? (The judges will look unfavourably on any content that takes longer than 3 minutes to view).

We'll review all submissions and our expert judging panel will grade tweets for clarity, wit, humour, scientific accuracy and originality (and, yes, spelling counts).

We'll also publish all submissions in the Rosetta blog. Only one entry will be accepted from each participant; the campaign closes 9 June; the winner will be announced on 10 June. 

And keep an eye on the sky — you never know what fantastic things you’ll see! -- Daniel

Editor's note: A very quick update before we head off to Toulouse to cover ATV docking - all's well that end's well with Rosetta's longer-than-expected manouevre campaign. SOM Andrea Accomazzo confirmed this morning that the final manourvre was indeed completed on 17 February

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I met on 10 February with Rosetta Spacecraft Operations Manager Andrea Accomazzo here at ESOC to catch up on all that's happened with Rosetta since our last update on 18 January.

Click to listen (or download) a full, 8:00-min recording of his explanation below, but to summarize, here is what has been happening:

• Rosetta experienced a safe mode - an automatic reset of the spacecraft - that happened during the thruster burn late in the evening of 18 January
• The safe mode stopped the thruster burn and placed the spacecraft into a basic, safe, Earth-pointing mode, waiting commands
• The teams here at ESOC spent the next few days determining the cause - which seemed to relate to how the thrusters function when in continuous operation
• In part by using a number of advanced tools and techniques developed here by the Advanced Mission Concepts and Technologies Office, the Rosetta team were able to isolate the problem
• The flight control team worked with flight dynamics experts to devise a new mode of operation for the thrusters - basically commanding them to switch rapidly on and off instead of running continuously as before
• The new thruster mode was extensively tested and simulated using software and the Rosetta engineering model, which is kept here at ESOC for just such purposes.
• A new set of manoeuvres were planned and uploaded, and during the last week of January, the spacecraft successfully re-started the manoeuvre campaign
• It has now completed almost 98% of the required change in velocity and is more or less lined up to meet Comet 67P/Churyumov-Gerasimenko in 2014
• The final manoeuvre of this new campaign will be conducted today, starting at 19:38 CET and running for about 43 minutes

Andrea and the rest of the team here at ESOC are just delighted! An initial problem that caused real concern and could have become critical has been investigated, analysed and a fix found - which enables the spacecraft to perform even better than before.

We'll update you again when we have news on the start of Rosetta's long hibernation, scheduled now for the June 2011 timeframe. -- Daniel

If audio does not play, download the original mp3 file here.