Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Fundamental Physics with a State-of-the-Art Optical Clock in Space



Andrei Derevianko, Kurt Gibble, Leo Hollberg, Nathan R. Newbury, Chris Oates, Marianna Safranova, Laura Sinclair


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.
Quantum Science and Technology


optical clock, relativity, time tranfser


Derevianko, A. , Gibble, K. , Hollberg, L. , Newbury, N. , Oates, C. , Safranova, M. and Sinclair, L. (2022), Fundamental Physics with a State-of-the-Art Optical Clock in Space, Quantum Science and Technology, [online], (Accessed July 15, 2024)


If you have any questions about this publication or are having problems accessing it, please contact

Created July 21, 2022, Updated March 17, 2023