Defense Advanced Research Projects Agency (DARPA)
An optical clock is waiting for a factory, not another laboratory demonstration
DARPA’s It’s About Time program moves optical clocks from proving they work in laboratories to proving a factory can build rugged units repeatedly. If that succeeds, systems could keep accurate timing during GPS outages, but the planned production line still has to meet practical limits on size, power, cost and platform integration.
Today, precise timing often depends on GPS. Communications networks, navigation systems and other distributed systems use its radio signals to stay synchronized. But those signals can be disrupted or denied. When that happens, a system needs a local clock that can keep time accurately without constantly listening to a satellite.
The best clocks for this job are difficult to make outside a laboratory. Most quantum sensors, including high-precision timing systems, are assembled in small custom batches by specialist technicians. They do not yet have shared procedures for assembly, calibration and testing. They are also sensitive to vibration, temperature changes, limited power and the demands of maintenance. A clock that works on a laboratory bench is not automatically a clock that can survive on a working platform.
From one-off instruments to production
DARPA announced the It’s About Time program on August 6, 2026. Its aim is to establish a pilot manufacturing pipeline for tactical-grade optical clocks. The work has been awarded to IonQ, using expertise from Vector Atomic, which IonQ acquired.
This changes the question being asked. Earlier work mainly asked whether an optical clock could be built and made to work. The new program asks whether a factory can build the same kind of clock repeatedly, test it in the same way and keep the performance that makes it valuable.
That distinction is easy to see in an ordinary object such as a bicycle. Building one bicycle by hand is different from making many bicycles whose parts fit, whose brakes are checked and whose performance is predictable. Optical clocks are far more complex, but they face the same basic manufacturing problem.
Why the clock is useful
An optical clock uses carefully controlled light and changes in atoms to keep time more accurately than conventional electronic clocks. The earlier ROCkN program took about five years to move from a laboratory breadboard clock to compact prototypes tested at national laboratories and in the field. DARPA says those prototypes showed long-holdover synchronization: they could preserve timing for a long period, with precision many orders of magnitude beyond GPS-grade timing.
The companion OASIC effort developed testbeds for component specifications, measurement methods, packaging, standardization and compatibility with older clocks. These steps matter because the clock is not useful merely for being precise in isolation. Its parts must be built, enclosed, measured and connected in ways that can be repeated.
It’s About Time will integrate optical clocks into Department of War platforms. The demonstrations will test beyond-GPS capabilities using timing precision at the picosecond level. In plain terms, the program is testing whether a very precise local clock can help systems keep coordinating when a continuous satellite signal is unavailable or contested.
What a factory could change
If the pilot pipeline works, military operators could have timing, navigation and communications that depend less on GPS. A distributed system could use highly accurate local timing during an outage instead of losing synchronization immediately. Transport, communications and infrastructure systems could also maintain tighter coordination, provided the clocks become compact, power-efficient and maintainable.
The same manufacturing methods could make other quantum sensors more practical outside specialist laboratories. That possibility depends on the factory, not just the physics. A manufacturing facility is expected to open by mid-2027, with production units available within a year of its completion.
Those dates do not guarantee a finished capability. The planned factory still has to meet requirements for production, size, weight, power, cost and integration with platforms. If it can repeatedly build and qualify rugged clocks, optical-clock timing may become an engineering supply problem rather than a laboratory-only achievement. Until then, the central test is whether the physics can survive being made over and over again.