On “new atlas” (see link below) you can find an interesting publication about the Menlo frequency comb developments and their future use. "Our device represents a cornerstone in the development of future space-based precision clocks and meteorology," says Matthias Lezius (Business Unit Leader – Research and Development) . "The optical clock performed the same in space as it had on the ground, showing that our system engineering worked very well."

Link to the article: http://newatlas.com/optical-clock-space-gps/46561/