Air Force chooses radiation-hardened atomic clock from Frequency Electronics

U.S. Air Force positioning, navigation, and timing (PNT) experts needed cyber- and radiation-hardened atomic clock technology for space satellites like the global positioning system (GPS) that require a high degree of synchronization. They found their solution from Frequency Electronics Inc. in Uniondale, N.Y.

Officials of the Air Force Research Labora­tory’s Space Vehicles Directorate at Kirtland Air Force Base, N.M., announced a $19.4 million seven-year contract to Frequency Electronics in April for the Space Qualified Atomic Clocks program. Frequency Electronics engineers will build and demonstrate a space-qualified atomic frequency standard (AFS) system for satellites that require a high degree of synchronization. Enabling technologies from this project will lend themselves to timing applications in Air Force space systems, and lead ultimately to demonstration of a space-qualified clock aboard a spacecraft flight experiment.

The AFS must be able to survive and operate through harsh-launch environments including high g-loads, vibration, and pyro-shock events in addition to severe on-orbit thermal cycling. The AFS also will be initially space radiation hardened sufficiently to survive a two-year lifetime at middle earth orbit (MEO). The traceable PDR design is envisioned as fully radiation hardened and survivable up to a 10-year lifetime at MEO. The AFS traceable preliminary design review (PDR) design should be fully radiation hardened and survivable to a 10-year lifetime at MEO.

This radiation-hardened space-based atomic clock is for demonstration aboard the future Navigation Technology Satellite (NTS)-3 space experiment. Air Force researchers expect that one heritage Rubidium Atomic Frequency Standard (RAFS) and two AFS clocks plus thermal control will fit into a hosted payload port of an evolved expendable launch vehicle (EELV) secondary payload adapter (ESPA) ring.

The AFS will support the standard 13.40134393 MHz Sinewave output, but also may need to support faster rates as necessary for other experiments with the future On-Orbit Reprogrammable Digital Waveform Generator (ORDWG). Company engineers also will develop the AFS to be impervious to cyber attacks — or cyber-hard by design for key mission-critical functions. They also will conduct a manufacturing readiness assessment for system manufacturability and affordability.

Frequency Electronics will do the work in Uniondale, N.Y., and should be finished by September 2025. For more information, visit Frequency Electronics online at www.freqelec.com.