On Monday, April 21st, the ACES/PHARAO (Atomic Clock Ensemble in Space) space mission was launched from Cape Canaveral to the International Space Station (ISS). After docking at the ISS, the robotic arm moved the ACES/PHARAO payload to its final location, outside the Columbus module. In-flight validation tests have now begun and will go on for several weeks.

PHARAO will be the first primary frequency standard in space. It exploits laser atom cooling techniques which, combined with the zero-g enviroment, will enable very low atomic velocities and, consequently, ultimate performance in terms of frequency accuracy; the objective is to reach 1.1×10^-16 in relative value.

The main purpose of the ACES mission is to carry out experiments in fundamental physics, and in particular to test Albert Einstein’s theory of general relativity. Some physicists believe that a ‘small’ deviation from general relativity is necessary to ensure its compatibility with quantum physics. Because this effect is so small, a space instrument with unprecedented accuracy is needed to measure it. With the ACES ensemble: PHARAO, hydrogen maser and time transfer modules, on board the ISS, and clocks on the ground, scattered around the globe and equipped with time transfer stations, this measurement becomes possible.

Ph.Laurent (PHARAO Scientific coordinator)

The LightBox project is based on an educational kit designed by the Atouts Sciences association (Laboratoire de Physique des Lasers – CNRS/USPN), enabling students to discover some remarkable properties of light through experimentation. The kit is used as the basis for scientific outreach activities, workshops and training courses. Over and above the dissemination of scientific culture, the aim of this project is to structure a national network of scientific referents, fostering the development of lasting links between teachers, organizers, young people and the world of research.

The LightBox kit is available free of charge to teachers, trainers, organizers, associations, museums and student clubs. Each project is led locally by a project manager (teacher, organizer, trainer, student, etc.) who is supported by a scientific advisor (a researcher, teacher-researcher, engineer or doctoral student) involved in the research. The project leader turns to the scientific advisor for all questions relating to his or her project, as well as for training, guidance and advice on how to use the equipment and carry out the experiments. In consultation with the project manager, the scientific advisor may be called upon to intervene directly with the project group (pupils, children) to run a workshop or give a talk. The scientific advisor can also host the project group for an event in its professional environment (laboratory, university, company, etc.). 70 projects have already been initiated in France, West Africa, Madagascar, Reunion Island and Peru (see Google Map: https://urlz.fr/oO4K)…

The kit is mainly supported by Labex First-TF, the Laboratoire de Physique des Lasers, Sorbonne Paris Nord University, the Société Française d’Optique, and has been recognized by UNESCO for the International Day of Light and by CNRS for the Year of Physics 2023/2024.

To join the project, click here: https://www.sfoptique.org/pages/sfo/lightbox.html