About the Facility

Precision timekeeping is vital to spacecraft positioning and accuracy. APL’s Time and Frequency Lab atomic clocks keep time to less than one billionth of a second to provide support to a variety of NASA and APL space missions of our solar system and beyond. Our engineering support for spacecraft includes providing precise time and frequency to the building and testing of spacecraft parts, evaluating the accuracy of the timekeeping systems, tracking and communicating with the spacecraft, and time-stamping data packets. APL’s Time and Frequency Lab was first established in 1959 under the Lab’s Transit program, the forerunner to the Global Positioning System (GPS) we rely on today for accurate timekeeping and position determination.