Fundamental physics with a state-of-the-art optical clock in space

Recent advances in optical atomic clocks and optical time transfer have enabled new possibilities in precision metrology for both tests of fundamental physics and timing applications. Here we describe a space mission concept that would place a state-of-the-art optical atomic clock in an eccentric orbit around Earth. A high stability laser link would connect the relative time, range, and velocity of the orbiting spacecraft to earthbound stations. The primary goal for this mission would be to test the gravitational redshift, a classical test of general relativity, with a sensitivity 30 000 times beyond current limits. Additional science objectives include other tests of relativity, enhanced searches for dark matter and drifts in fundamental constants, and establishing a high accuracy international time/geodesic reference.

Automated summary

Recent advances in optical atomic clocks and optical time transfer have opened up new possibilities for precision metrology in fundamental physics tests and timing applications. A proposed space mission concept would place a cutting-edge optical atomic clock in an eccentric orbit around Earth and establish a high stability laser link with earthbound stations. The primary objective of this mission is to test the gravitational redshift with a sensitivity far beyond current limits, as well as explore other aspects of relativity, search for dark matter, and establish a highly accurate international time/geodesic reference.