Development of compact lattice optical clocks towards future space clocks

Within the ELIPS program of ESA, the “Space Optical Clocks” (SOC) project aims to install and to operate an optical lattice clock on the ISS towards the end of this decade. In this project two accurate transportable lattice optical clock demonstrators having relative frequency instability below 1×10
^-15
at 1 s integration time and relative inaccuracy below 5×10
^-17
are under development. Crucial requirements are moderate volume, electrical power consumption and mass, and robustness. Furthermore, a modular concept is favourable.