ACES

ACES is a new generation of atomic clock that takes advantage of the microgravity environment of the ISS. The ACES payload will distribute a stable and accurate time base that will be used as a reference for comparisons of several ground clocks with ACES as a relay. The direct comparison of ultra-precise atomic clocks is crucial for exploiting the potential of ACES in various fields of research: fundamental physics (General Relativity and String Theory tests), Time/Frequency metrology, but also geodesy and gravimetry, precise orbit determination, Earth tracking, very long baseline interferometry, global positioning and navigation.