A superconducting microwave oscillator clock for use on the Space Station

The International Space Station provides an ideal platform for high precision frequency measurements, both as applied to scientific experiments and as regards basic time metrology. Consequently, a variety of clocks are being developed for flight on the Space Station, a majority of which are atomic clocks with very good stability for time periods in excess of 1,000 seconds. We plan to significantly augment the scope and capability of the ensemble of space clocks by adding to it SUperconducting Microwave Oscillator, SUMO. SUMO is a space version of the superconducting cavity stabilized oscillator, SCSO; the most precise clock developed to date for the interval range of around 100seconds. Short descriptions are given of the SUMO project and the SCSO technology and the principal disturbances causing frequency fluctuations are outlined. The planned improvements to the SCSO and preliminary results of the development work for SUMO are also highlighted.