DARPA Is Building a Portable Atomic Clock With Trillionth of a Second Accuracy

The machines could be strapped to aircraft and even satellites.

DARPA

U.S. government agency DARPA announced the Robust Optical Clock Network (ROCkN) program, which aims to build a super-accurate optical atomic clock compact enough to fit inside a military aircraft or field vehicle, a report from New Atlas reveals.

In military operations, nanosecond-level accuracy is required for military craft to fire weapons at high speed and at extreme ranges. Even an error of a billionth of a second could cause a missile to miss its target. To this end, the modern military is heavily reliant on GPS, but the technology isn't always available and it can even be jammed by adversaries. 

Atomic clocks could provide a solution by allowing field units to tell the time with ultra-precise accuracy, without the need to connect to GPS. The technology uses a beam of microwaves to measure the frequency of atoms as they change energy state. The most accurate type of atomic clock is the optical atomic clock, which replaces the microwaves with a beam of light, boosting the accuracy by a factor of 100. Optical atomic clocks are so accurate, in fact, that they wouldn't have lost a second over the universe's entire existence of more than 13 billion years.

Portable atomic clocks

Typically, optical atomic clocks are large cumbersome machines, but DARPA's ROCKn program aims to make them smaller and lighter so they can be fitted into military vehicles, and even satellites. 

"The goal is to transition optical atomic clocks from elaborate laboratory configurations to small and robust versions that can operate outside the lab," Tatjana Curcic, program manager in DARPA's Defense Sciences Office, said in a statement. "If we're successful, these optical clocks would provide a 100x increase in precision, or decrease in timing error, over existing microwave atomic clocks, and demonstrate improved holdover of nanosecond timing precision from a few hours to a month. This program could create many of the critical technologies, components, and demonstrations leading to a potential future networked clock architecture."

The technology could have applications for space exploration too. In 2019, NASA activated its Deep Space Atomic Clock, which is crucial for enabling accurate space navigation in the future. Much in the same fashion as military operations, space navigation requires incredibly precise reading over the enormous distances traveled. Portable optical atomic clocks, therefore, have the potential to allow future spacecraft to navigate the cosmos with greater ease.

Source: https://interestingengineering.com/darpa-is-building-a-portable-atomic-clock-with-trillionth-of-a-second-accuracy