General Atomics

ACES docked with ISS

Following its Falcon 9 launch from Kennedy Space Center, the Airbus-built ACES (Atomic Clock Ensemble in Space) has now docked with the International Space Station (ISS).



Above: ACES Production in Friedrichshafen.
Copyright Airbus


ACES is an ESA-led payload developed by Airbus to bring ultra-precise timekeeping to the ISS. It features two cutting-edge atomic clocks 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.

In March, the ACES instrument left the Airbus site in Friedrichshafen, Germany, where it was built and tested, for Florida, from where it has been launched.

The two atomic clocks in ACES’ payload are a laser-cooled Cesium atom clock (PHARAO, made by CNES in France) and an active Space Hydrogen Maser  (SHM, made by Safran Timing Technologies in Switzerland). The combined extremely precise (theoretical time deviation of one second in 300 million years) clock signal is sent to the ground via a microwave link.

Eight ground terminals are distributed worldwide allowing ground clock comparison with the payload. The first communication links are expected to occur in only a few days’ time.

The last step now remaining before the start of the mission will require the Canadian Space Agency’s robotic arm to attach ACES to the exterior of ESA’s Columbus laboratory, currently planned for 25th April.

Related

Bristow Group acquires Berry Aviation as it shifts further into government services
Bristow Group helicopter in flight
Bristow Group acquires Berry Aviation as it shifts further into government services
Bristow Group’s $105 million acquisition of Berry Aviation will add defence, ISR, mission support and unmanned systems capabilities to its Government Services business.
Airbus Belfast delivers 500th A220-300 wingset after becoming fully integrated
Belfast 500th A220300 wings
Airbus Belfast delivers 500th A220-300 wingset after becoming fully integrated
Airbus Belfast has completed its 500th A220-300 wingset, just months after the former Spirit AeroSystems facility came under Airbus ownership.
Aerospace

3 Jul 2026

Skybus managing director leaves with immediate effect
Jonathan Hinkles, a highly experienced airline executive with over 30 years in the industry, who has stepped down from Skybus
Skybus managing director leaves with immediate effect
The unexpected departure comes just months after the airline was at the centre of the high-profile collapse of Cornwall's subsidised London Gatwick air service.
Aerospace

2 Jul 2026

Rolls-Royce Submarines breaks ground on major Derby expansion to support AUKUS
AUKUS submarine
Rolls-Royce Submarines breaks ground on major Derby expansion to support AUKUS
Rolls-Royce Submarines has broken ground on a major expansion of its Raynesway site in Derby, doubling manufacturing capacity.
Defence

3 Jul 2026

Bristow Group acquires Berry Aviation as it shifts further into government services
Bristow Group helicopter in flight
Bristow Group acquires Berry Aviation as it shifts further into government services
Bristow Group’s $105 million acquisition of Berry Aviation will add defence, ISR, mission support and unmanned systems capabilities to its Government Services business.
BAE Systems offers a sneak peek into near-complete GCAP Tempest demonstrator
BAE Systems GCAP Tempest demonstrator over London
BAE Systems offers a sneak peek into near-complete GCAP Tempest demonstrator
Why Tempest/GCAP 75% complete milestone shapes it up to be the world's primary export-oriented 6th-generation fighter jet.
Defence Most Read

3 Jul 2026

BAE Systems’ Endura demos radiation-hardened capability for space missions
BAE Systems’ Endura demos radiation-hardened capability for space missions
BAE Systems has successfully demonstrated the ability of its Endura system-on-chip (Soc) space processor…
Space

29 Jun 2026

BAE Systems to build high-res imagery satellites for Vantor
BAE Systems to build high-res imagery satellites for Vantor
BAE Systems has entered into an agreement to build high-resolution imaging satellite buses for Vantor, a provider of unified spatial intelligence from space to ground.
Space

25 Jun 2026

ADS appoints Matthew Reynolds as CIO
ADS appoints Matthew Reynolds as CIO
ADS Group - parent organisation of trade association ADS and Farnborough International - has appointed Matthew Reynolds as its Chief Information Officer (CIO).
Aerospace Defence Events Security ...

19 Jun 2026

Smiths Detection completes transition to CVC Capital Partners
Smiths Detection completes transition to CVC Capital Partners
Smiths Detection completes transition to CVC Capital Partners
Smiths Detection has completed its transition from Smiths Group to CVC Capital Partners (CVC), a private markets investment firm.
Aerospace Security

1 Jul 2026

Serbus acquires Westica
Serbus acquires Westica
Serbus acquires Westica
Provider of secure Critical National Infrastructure (CNI) networking and communication solutions, Serbus, has acquired Westica Communications Limited (Westica), for an undisclosed sum.
Defence Security

30 Jun 2026

CAA warns of risks posed by incorrectly packed batteries
Pack right. Safe Flight. CAA
CAA warns of risks posed by incorrectly packed batteries
Ahead of the big summer getaway where over 60 million people are expected to…
Aerospace Security

26 Jun 2026