ACES on its way to orbit: Ultra-precise European atomic clocks now in space

ACES lifted off on a SpaceX Falcon 9 from Launch Complex 39A at NASA’s Kennedy Space Center in Florida, United States, as part of the 32^nd SpaceX commercial resupply services mission to the International Space Station.

“The launch of ACES marks a major milestone for European science and international cooperation in space. With this mission, we are placing the most precise timepiece ever sent to orbit aboard the International Space Station — opening new frontiers in fundamental physics, time transfer, and global synchronization. ACES is a shining example of what Europe can achieve when we unite cutting-edge technology, scientific ambition, and strong partnerships”, says Daniel Neuenschwander, Director of Human & Robotic Exploration at ESA.

ACES is a fully European mission led by ESA, with Airbus as a prime contractor. Its two clocks, PHARAO and the Space Hydrogen Maser (SHM), were built by the French space agency CNES and Safran Timing Technologies in Switzerland. Together, these ultra-precise clocks will generate a time signal so precise that ACES would lose just one second in 300 million years. The time transfer system is built by TimeTech in Germany and will use microwave and laser links to synchronise time between space and Earth with an accuracy far beyond today’s systems. The mission will be operated from CADMOS (France) and the Columbus Control Centre (Germany).

Later this week, currently scheduled for 25 April, the Station’s robotic arm will install ACES on the External Payload Facility of ESA’s Columbus module, in the nadir (Earth-facing) position. Over its 30-month mission, ACES aims to conduct at least ten extended measurement sessions, each lasting 25 days, as it orbits Earth 16 times daily.

More information:

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

https://blogs.esa.int/exploration/the-clocks-of-aces/

https://esamultimedia.esa.int/docs/ACES_Factsheet.pdf

https://blogs.esa.int/exploration/7-things-you-didnt-know-about-aces

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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.

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

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