NASA’s Deep Space Atomic Clock, which launched on a satellite in June 2019, outperformed all other clocks in space during its first year in orbit around Earth.
Space navigation
To navigate the solar system today, space probes listen for signals from antennas on Earth and then bounce those signals back.
Ultraprecise, refrigerator-sized atomic clocks on the ground measure that round trip time — which can take hours — to pinpoint a spacecraft’s location.
DSAC
The Deep Space Atomic Clock (DSAC) is a miniaturized, ultra-precise mercury-ion atomic clock for precise radio navigation in deep space.
DSAC could simply measure how long it takes a signal from Earth to arrive and calculate its own position.
The Deep Space Atomic Clock (DSAC) is as stable as a ground clock.
DSAC is so stable because it keeps time using electrically charged atoms, or ions, rather than neutral atoms.
It is expected that a DSAC would incur no more than 1 microsecond of error in 10 years of operations.
It is expected to improve the precision of deep space navigation, and enable more efficient use of tracking networks. The project is managed by NASA's Jet Propulsion Laboratory.