Radio interferometry using multiple small satellites will enable measurements with high angular resolution for remote sensing and astronomy. The NASA sponsored Auroral Emissions Radio Explorer (AERO) and Vector Interferometry Space Technology using AERO (VISTA) CubeSats will demonstrate orbital interferometry from 0.1 MHz to 15 MHz, frequencies which are largely blocked by the ionosphere. We report on the design and testing of a clock system for radio interferometry between these orbital receivers. We discuss the clock system design up to PCB fabrication, including requirements flow and major hardware trades. The performance of the timing components has been verified using a phase noise test set with a high-quality benchtop crystal. While these results are presented for the AERO-VISTA mission payload, they are more generally applicable to any orbital interferometry platform with multiple satellites
