KM3NeT - ORCA

Welcome, ORCA-42!

8 July 2026 – A very successful sea operation took place during last week-end, leading to a new extension of the ORCA submarine telescope off the coast of Toulon, France.

During the operation, four new detection units were installed in the deep sea and connected to the detector in a record time of an average 8.5 hours of operation per unit.

Ancillary actions were also performed, including a deep-sea inspection of some detection units, recovery of one acoustic emitter of the positioning system which requires some maintenance and recovery of biofouling traps installed years ago which will provide new insights on how to preserve the transparency of the glass of the optical modules in the deep sea over very extended periods.

At the end of the operation, the apparatus comprises 42 detection units.

As usual, the operation was performed with two ships: the Castor 02 of Foselev, for deployment of the detection units, and the Janus II of SAAS (formerly Comex), equipped with the Apache deep-sea remotely operated vehicle (ROV), for submarine operations.

Many thanks to the crews offshore as well as to the team who performed the functional tests of the new detection units from the shore station and anyone else involved in making this great step forward possible!

Welcome, ORCA42!

Sonar map of the deep-sea installations at ORCA at the end of the operation, comprising two nodes for submarine connections (marked N1 and N2), a calibration base (CB) connected to an instrumentation unit (IU), and a total of 42 detection units (DUs) – those installed during the latest campaign are marked.


Welcome, ORCA-38!

20 April 2026 – A very successful sea operation took place last week, leading to a new extension of the ORCA submarine telescope off the coast of Toulon, France. Read more


Second node of ORCA installed

13 August 2025 – Last week we installed a second submarine node for the ORCA neutrino telescope. It is an important step in preparation of the next deployments of detection units for ORCA.

Read more



Welcome ARCA33 and ORCA24!

28 October 2024 – The latest sea campaigns at both the KM3NeT’s ARCA and ORCA sites have led to major progress in expanding detector installations and improving calibration systems.

The number of detection units in operation in the deep sea has been increased to 57: 33 in ARCA and 24 in ORCA.

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Three more detection units for KM3NeT/ORCA

1 May 2023 – During a two days sea operation, 27-28 April 2023, three detection units were successfully connected to the ORCA detector of KM3NeT in a record time of just over 24 hours. In addition, an acoustic beacon was recovered for battery replacement. The total number of deployed ORCA units is now 18, as visible in the sonar scan above.

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KM3NeT@neutrino2022

Fifty years ago, in 1972, the first neutrino conference was held in Hungary, because the organisers were not satisfied with the subdued position of neutrino interactions at the international conferences at that time. Nowadays, the neutrino conference is one of the major conferences in neutrino (astro)particle physics. Neutrino2022 took place in virtual Seoul, 30 May-4 June, 2022 and of course KM3NeT was there to show the results of data taking with the first detection units of ARCA and ORCA.

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Welcome, ORCA-10!

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

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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.

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