The 23rd July 2012 was an historical day for the EPS as well as for the town of Chamonix in the Haute Savoie of France. Seven astronauts from the Endeavour Space Shuttle mission STS-134 arrived in Chamonix to be part of the 100 years celebration of the confirmation by Nobel prize-winner Viktor Hess of the extra-terrestrial origin of cosmic rays. Chamonix subsequently played a significant role at the Laboratoire des Cosmiques, among the glaciers high above the town of Chamonix. The EPS Historic Sites committee had prepared a plaque to mark the event, with a citation which reads as follows.
In 1943, during the war, here at 3613 m above sea level, the French CNRS-National Centre for Scientific Research established a high altitude laboratory under the aegis of Louis Leprince-Ringuet to study the cosmic rays and their applications in nuclear physics. In 1946, the laboratory was inaugurated in the presence of Irène Joliot-Curie and continued to be operated until 1955. High voltage lines suspended above the glaciers supplied the necessary electric power. "This is how up there – in the words of Leprince-Ringuet – in really sporty conditions, with an electric cable, a local electricity power source, some electron counters, a small Wilson apparatus, we managed to study particles from cosmic radiation."
What linked the astronauts to Chamonix? The answer lies in the Alpha Magnetic Spectrometer (AMS-02) payload which the shuttle mission flew up to the International Space Station on 16 May 2011, on its last flight. The AMS is the latest in a long line of spectrometers to study cosmic rays, taking progressive advantage of the reduced attenuation in the upper atmosphere, from short balloon flights, through high altitude installations and finally to the multi-decade programme of the orbital AMS. The spectrometer in the Refuge des Cosmiques was one of the first terrestrial high-altitude installations. A Wilson chamber was combined with a magnet requiring a 55kW DC supply. The research post had been constructed in the most severe conditions, often requiring back-breaking transport of tons of material over the glacier. Many decades later, the AMS-02 itself had been partly constructed at CERN, thereby creating the synergy of this event between AMS, CERN and Chamonix as well as the EPS.
The day began early on an exceptionally glorious morning, gathering the astronauts, some of their family (the singular is appropriate since it was obvious that this was one big extended family) at the foot of the Téléphérique des Aiguilles du Midi to equip the astronauts for the rigours of these altitudes. The group took up the EPS commemorative plaque, shown in the photo with the citation. It was accompanied up to the summit by Jo Lister, representing the Executive Committee. Three of the astronauts braved the exposure of the Arrête des Cosmiques and descended to the Refuge des Cosmiques which is a very short distance from the abandoned hut housing the original cosmic spectrometer. The remainder of the party took a spectacular ride across the glaciers to Heilbronn and back.
STS-134 astronauts (left to right) Mark Kelly, Roberto Vittori and Gregory Johnson holding the EPS commemorative plaque at the 'Refuge des Cosmiques'
There had been an impressive media coverage preceding the event and a public lecture took place in Chamonix in the afternoon, to celebrate the visit by the astronauts and the inauguration of the EPS plaque. A packed auditorium heard an inspiring scientific presentation by Prof. Maurice Bourquin of the University of Geneva, explaining the history and importance of cosmic ray research. A film of life on the International Space Station followed, underlining that it is impossible to become bored with the amazing images of and taken from the ISS. A long question and answer session, in which the astronauts had agreed to field all sorts of questions from the audience, exposed both the interest and the scientific culture of the local attendees.
The EPS warmly recognises the Commune of Chamonix, the Compagnie des Guides de Chamonix and the Compagnie du Mont-Blanc, Chamonix for their contributions to the success of this exceptional day, and above all recognises the overall organisation of the event under CERN hospitality.