Context

• 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.

https://www.sciencenews.org/article/atomic-clock-deep-space-travel-nasa-passed-first-test

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