by Federico Ronchetti – ALICE Run Coordinator . Published: 24 March 2015

I am deeply struck by the reaction of people when they visit CERN. Although most of the visitors come with vague expectations, nothing can replace the unmediated view of the most complex machines ever built by mankind. CERN is the home of the Large Hadron Collider – the biggest and most powerful accelerator in the world: if the LHC ring, with its 27-km long circumference, was on the earth surface, it would be, together with the Great Wall, one of the human artifacts visible from the space vehicles spinning around the planet on lower orbits. The drawback of such magnitude is that one cannot really embrace the LHC in a single view from the ground. It’s just too big.

So, the breath-taking experience really comes from the opportunity to descend into the caverns hosting the giant detectors operating on the LHC itself. Hence, the long shutdown of the accelerator after its first operation phase was a unique chance to see the underground installations. In fact more than 70.000 people visited CERN during the Open Days in 2013 and about 4.000 came to visit ALICE. Before guiding the visitors down to the cavern, we usually show introductory slides describing the scientific mission and the complexity of the ALICE detector, and we inform the audience about its many highlights. Axonometric drawings are shown and physical dimensions are quoted: 16 m high, 25 m long, 10.000 tons of weight and so on. However, those numbers don’t really stick in people’s mind until they are able to see with their own eyes the cyclopic iron doors of the solenoid magnet, the multiple layers of detector sensitive elements packed together and densely instrumented with electronics boards, the intricate networks of data and power cables, the cooling pipes, the support structures.

Unfortunately, not everyone can come to CERN and visit LHC and our detectors. Moreover, the maintenance period is finished and for more than three years the underground areas will be inaccessible to the general public. This fact gave me the feeling that many would miss a unique opportunity. When I found out that my colleague at INFN Francesco Sborzacchi together with Benedikt Langhans had operated a drone for the LHCb evacuation exercise, I kindly asked them if they would be willing to fly their drone in ALICE, as shooting an aerial video sequence seemed a unique opportunity to convey to those who could not personally visit the experimental installations a true “CERN experience”.

First of all, a short test flight was done to verify the stability of the drone operation in the cavern since the electronic pickup of the remote control and the lack of GPS stabilization usually available in open spaces could make the drive difficult. As the test appeared to be successful, Francesco, Benedickt, and myself spent few hours, on a mid-summer afternoon, flying the drone over the ALICE site, all the way down to the shaft, in front of the ALICE solenoid, over the beam pipe and finally we hovered it on the central barrel and all the way up to the muon spectrometer. As a result, we got several hundred GB of video and photographic material, which constitute the base for the making of what we called the  “ALICE drone flight” footage. The concept for the video was very precise: a three-minutes clip, with dynamic scene changes, no voice-over but short captions with simple yet informative content.  We wanted the viewer to fly from the space over ALICE site, peek into our new state-of-the art control room, jump into the shaft and “inspect” the detector as close as possible, at times “sticking the nose inside it”. The sequences with the time-lapse of the magnet door closure and the collision event examples were added to explain the readiness status and the ALICE scientific mission, respectively.

Having a sequence in mind and having a finished video product are two different things, so an in-house, pre-production footage was kindly realized by Daniele de Gruttola, following my requests.

Being able to show a pilot video turned out extremely useful once we passed the material to the CERN media service, where James Pym recreated the sequence from scratch but following closely Daniele’s timeline. James also developed the initial and final animations. Afterwards came the captions, in many different versions, which were refined with the help of Stefania Bufalino while we were in the ALICE Run Control Centre for the detector commissioning work in November 2014.

The result of all this cooperative work, with the help of Julie Hadre, became the “Flying over ALICE” footage, which was published on the CERN and ALICE social media channels such as Twitter and Facebook. Major US news web sites as NBC News, Discovery News and CNET instantly picked up the footage. After few days, bookkeeping the list of sites which linked the ALICE video became too hard as it basically hit all over the world being re-launched in the UK by the BBCClick Twitter account (2.4 M followers) and several nation-wide news sites in Germany, Italy, the Netherlands, Spain, Portugal, Singapore, Africa (Sierra Leone) and South Africa, and probably others.


As of today the overall score of the original “Flying over ALICE“ video on YouTube has reached almost 35.000 hits and its still being viewed. It should be mentioned that many news sites (as NBC for instance) did provide their own streaming which means that the number of effective viewers is much larger than the YouTube count.

We are also very happy to see that we inspired others since recently more CERN experiments are releasing drone videos: as someone once said  “imitation is the sincerest form of flattery”.