N° 18–2025: Media invitation: ACES pre-launch media briefing (online)

Participants will have the opportunity to learn more about this mission and ask their questions by joining an online pre-launch media briefing in English via Webex at 12:00 CEST on Thursday 17 April 2025.

ACES is scheduled to launch on Monday 21 April on SpaceX’s Commercial Resupply Service mission 32 (SpX-32). It will travel to the International Space Station in a Cargo Dragon capsule atop a Falcon 9 rocket. Once docked to the Station, the Canadian Space Agency’s robotic arm will attach ACES to the exterior of ESA’s Columbus laboratory at a later date, currently planned for 25 April.

The briefing will include an introduction, opening remarks and a Q&A with the following experts:

• Simon Weinberg, ACES Project Manager, ESA
• Patrick Crescence, Project Manager, Airbus
• Didier Massonnet, Pharao Project Manager, CNES
• Philippe Laurent, Responsible of PHARAO-ACES Activities, Observatoire de Paris

Media registration

Journalists are requested to register by 17:00 CEST on 16 April at the latest to receive access codes for the ESA WebEx online session. Only those registered will be able to ask questions: https://blogs.esa.int/forms/esa-media-briefing-form/

About ACES

The Atomic Clock Ensemble in Space (ACES) is an ESA-led instrument developed with Airbus to bring ultra-precise timekeeping to the International Space Station. It features two cutting-edge atomic clocks – Pharao (CNES) and the Space Hydrogen Maser (SHM, by Safran Timing Technology in Switzerland) – that will work together to generate the most accurate time signal ever sent from space. By linking the best clocks on Earth with its own, ACES will test Einstein’s theory of general relativity, improve global time synchronisation and advance our understanding of fundamental physics.

More information:

https://www.esa.int/Science_Exploration/Human_and_Robotic_Exploration/ACES_Atomic_Clock_Ensemble_in_Space

Images

https://photolibrary.esa.int/home-page/

Videos

https://www.esa.int/esatv/Videos/2025/03/ACES_Atomic_Clock_Ensemble_in_Space

Social media

X: @esa @esaspaceflight 
BlueSky: @esa @exploration.esa.int
Instagram: @europeanspaceagency 
Facebook: EuropeanSpaceAgency 
YouTube: ESA 
LinkedIn: European Space Agency - ESA 

About the European Space Agency

The European Space Agency (ESA) provides Europe’s gateway to space.

ESA is an intergovernmental organisation, created in 1975, with the mission to shape the development of Europe’s space capability and ensure that investment in space delivers benefits to the citizens of Europe and the world.

ESA has 23 Member States: Austria, Belgium, the Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Luxembourg, the Netherlands, Norway, Poland, Portugal, Romania, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. Latvia, Lithuania and Slovakia are Associate Members.

ESA has established formal cooperation with other four Member States of the EU. Canada takes part in some ESA programmes under a Cooperation Agreement.

By coordinating the financial and intellectual resources of its members, ESA can undertake programmes and activities far beyond the scope of any single European country. It is working in particular with the EU on implementing the Galileo and Copernicus programmes as well as with Eumetsat for the development of meteorological missions.

Learn more about ESA at www.esa.int