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Intermediate outcome of the ARCA campaign: 2 junction boxes and 12 detection units operational

6 June 2022 – The first round of activities of the ongoing sea campaign at ARCA has been completed.

In a summary, in the past week-end:

  • we installed two submarine junction boxes, one of which in replacement of the temporary junction box that we have used so far
  • the temporary junction box has been safely recovered
  • we moved all connections of the detection units already installed on the sea bed onto the new junction boxes
  • we installed 4 new detection units (where, by installation, one should understand that each detection unit was lowered to the bottom of the sea, carefully placed on the sea bottom, connected to the junction box and unfurled to reach its nominal, upright configuration)

Each of the steps above comprised dedicated tests, requiring careful coordination of the activities of the onshore and offshore teams.

And… the campaign is not yet finished! The ship is now heading back to Malta to load an additional set of detection units to install.

Stay tuned, as there will be more to report in the next days!

Preparation to deployment of the first detection unit to be installed during the campaign. On the right of it is one of the junction boxes awaiting installation, on the left the temporary junction box recovered from the sea floor.


The first detection unit installed in this campaign gracefully splashes into the water, to start its journey down to 3,500 m depth.


New sea operation started at ARCA

3 June 2022 – A new sea operation was started yesterday aiming at a significant enlargement of the ARCA neutrino telescope.

This is a major step forward for the Collaboration, as this is the first time ever that we launch a 2-weeks campaign. The scope of the operation in fact is twofold: upgrade the submarine network, by installing 2 brand-new junction boxes in replacement of the junction box that we have been operating so far, and to install new detection units (DUs). The operation will therefore take place in two steps: after the first round of activities for installation of the junction boxes and the first 4 DUs, the ship will come back to shore to pick up an additional set of DUs.

Handin Tide, which has already performed the previous sea campaign for KM3NeT ARCA last year, is the ship which will conduct this operation.

The ship left the port of Malta yesterday afternoon.

Remain connected, as we will be posting news about the operation while the action goes on – on our blog and on our social channels.

A set of KM3NeT DUs ready for deployment in the port of Malta earlier this week.


Loading of a KM3NeT DU onto the Handin Tide.

The Handin Tide sailing off from Malta in the afternoon of yesterday, June 2.

A vibrant Collaboration meeting in Athens

27 May 2022 – Last week the KM3NeT Collaboration joined in Athens for an in-person Collaboration meeting. It was a long-awaited achievement, after two years of remote meetings.  Many thanks to our hosts at NCSR Demokritos for an excellent organisation!

The pleasure to be together again gave new impulse to all activities, and vibrant discussions took place about progress in construction of ARCA and ORCA, preparation of deployments campaigns and the latest methods and results of data analysis.

Besides the fact that we were extremely happy to meet in person again, we have also learned from the pandemic and our ZOOM-experience: With an eye on sustainability, family situations or other obligations, we also offered the possibility to join the meeting remotely. Which worked great!

Of course we also discussed about the war in Ukraine: With deep sadness for the horror which has been developing there for months now, the Collaboration decided to formally suspend all relationships with public institutions in Russia, including those institutes which had a status of observer institutes in the Collaboration. This won’t impact, though, on the solidarity and friendship with our colleagues in Russia, many of whom have openly stood up against the war, who will be therefore still welcome to participate in KM3NeT on a private basis.

During the meeting, the University of Georgia, which participates in KM3NeT with a team led by Kakhaber Tavzarashvili, changed its membership status from observer to member institute, and several colleagues from various institutes made their debut.

Finally, the meeting gave a good opportunity to refine the plans for the newly approved projects of KM3NeT Infradev-2, supported by EU, and the French project NEUMED.

What a feeling to take a nice Collaboration picture again!

Welcome, ORCA-10!

22 November 2021 – Four new detection units have been added to ORCA with a 5-day intense and successful sea operation.

The operation has been performed with two ships: the Castor, equipped for deployment and precise installation of the detection units on the sea floor, and Janus, equipped with a remotely operated vehicle used for inspecting and for connecting the new units to the submarine infrastructure.

You can read all details of the operation in the daily reports published in our ORCA-blog.

Data taking with 10 detection units has been started!

One of the new detection units of ORCA outboard of Castor, preparing to its journey to the seafloor, 2,500 m below.

Sea campaign completed: 10 detection units in operation at ORCA

22 November 2021 – Excellent progress today, with the work finalized on the two detection units lately deployed: after a confirmation from the tests that both were ok, the unfurling was started of the two units. The launcher vehicles were safely recovered from the Castor; the ROV inspected both units after unfurling, confirming that both are in nominal configuration. A new functionality test was then performed from the shore station to ensure that both detection units work nominally.

As the sea condition rapidly degraded during the day, it was decided to quit the campaign. The remaining detection units on deck will be saved for next time.

The final outcome of the campaign is: ORCA enlarged from 6 to 10 detection units!

The KM3NeT Collaboration is grateful to the heroic teams who have made such great effort onboard the two ships and in the shore station, as well as to all institutes which contributed to the construction of the detection units. We look forward to the next deployment campaign. Having said that: it’s time to resume data taking with an enlarged ORCA-10 now!

Approaching the ORCA submarine junction box at 2,500 m depth – in the foreground is the connector that the ROV is preparing to plug on it.
The team onboard the Janus – on one of the screens is the sonar image of the ORCA telescope, showing the nodes and the detection units on the sea floor. Note that the operation was performed respecting all applicable rules for protection against COVID-19 – the team got so close together only for the purpose of the picture.
The team onboard the Castor showing the ’10’ sign in front of a recovered launcher vehicle.
The onshore team. The featured instrument is an Optical Spectrum Analyser, showing the signals of the 10 detection units of ORCA. Note that the operation was performed respecting all applicable rules for protection against COVID-19 – the team got so close together only for the purpose of the picture.

News from the ORCA campaign – hard work ongoing, bad weather approaching

21 November 2021 – The weather forecast does not look promising for next days. The main effort today was spent on some tuning of the equipment and preparation to next steps.

The situation at the sea bottom is: two new detection units have been already added to the ORCA detector; a third one, after installation, connection and test, is awaiting unfurling, and a fourth one is also on the sea floor awaiting to be connected – next step will be to connnect this one.

The video shows the overboarding of the ROV from the Janus – this takes place by means of a so-called A-frame (the structure at the stern of the ship which, rotating, reaches outboard).

Two new detection units added to ORCA… and counting

20 November 2021 – It was night and day again. The work continues around the clock when you are at sea. The second detection unit was also deployed, connected and tested last night. After that, unfurling was performed for the two detection units. A final test was then made from the shore to check that the two units are ok even after unfurling, et… voilà:  ORCA is enlarged to 8 detection units.

The campaign is now continuing with deployment of the next detection units; a third one is already on the sea bottom, connected and tested. A fourth one has been deployed in the evening: we will keep going until the deck is empty or the weather changes (the forecast is not ideal for next week): which of the two will happen first?

After unfurling of a detection unit, the launcher vehicle on which the unit is installed for deployment reaches the surface and is recovered for next campaigns.
Inspection of a detection unit, after touchdown on the sea floor (~2,500 m depth). The unit featured here is the fourth one which has been deployed in this campaign.

First day of activity at the ORCA site

19 November 2021 – The first day of activity has gone at the ORCA site. Most efforts today were aimed at getting everything well prepared for the action. The first detection unit was then deployed to the sea bottom, precisely placed on the sea floor and connected to the submarine infrastructure. The tests performed from shore confirm that the dection unit is nicely working, and it now awaits to be “unfurled” to its work configuration. Deployment of the second detection unit has been started in the evening.

Today was also the last day of our joint ANTARES-KM3NeT online Collaboration meeting, which ended with a cheerful activity to enjoy each other’s company even from a distance – you can read more about the meeting here.

The tho ships in action at the ORCA site: Castor (in the foreground) is equipped for deploying and accurately placing the detection units on the sea floor, while the Janus (in the background) is equipped with a ROV for submarine connections.

The movie shows the overboarding of one of the new detection units of ORCA.



Online but happy collaboration meeting

19 November 2021 – Our collaboration met this week for its traditional Fall meeting – the 5th to be organised online. Despite the physical distance, we had lively and interesting exchange over the week. Many new data analyses were presented, and more than 120 participants connected to the sessions. The week ended by fun social events, and the wish to chat face to face, in-person at the next meeting.



We also welcomed new institutes in the Collaboration:

– University of Sharjah, UAE;
– Khalifa University, UAE;
Lebedev Physical Institute, Russia;
UCLouvain, Belgium.

The new institutes will work on various topics ranging from neutrino astronomy to neutrino physics, while contributing to detector construction. Welcome in the collaboration!

Finally, we celebrated 6 months of ARCA data taking with 6 detection units! For the occasion, some of the artists in our collaboration prepared a 6hand piano piece. Enjoy!

New sea installation started for ORCA! Follow it from our blog

18 November 2021 – Right in the middle of the joint ANTARES and KM3NeT Collaboration meeting, which is taking place  – once again – online, a new sea campaign has been started for ORCA. Isn’t it the right way to show that a virus can’t stop science?

Today, November 18th, seven new detection units of KM3NeT, onboard the Castor ship of Foselev Marine, sailed from La Seyne sur Mer in Southern France to the KM3NeT/ORCA deep-sea site, about 40 km from the shore. The aim of the campaign is to deploy as many of them as the weather, which is not ideal in this season, will allow.

As in the past campaigns, two vessels will be used for the operation: the detection units will be deployed and precisely installed on the sea floor from the Castor, while a remotely operated vehicle will be maneuvered from the Janus of Comex.

We will document the activites of next days through our liveblog and over our social media channels.

Remain connected with us for this new, extraordinary challenge from the deep sea!

The deck of the Castor packed with detection units, while preparing to sail.