The Engineering Model design of the Optically pumped Space Cs Clock (OSCC) was completed in 2016 and is reported. The design describes a system of 12liters, 10kg, 30W power consumption and 12 years lifetime. It will be partially manufactured in 2017. In parallel, in depth analysis of the clock environment sensitivities was carried out and new laser sources were tested. The short-term stability of an existing Elegant Breadboard Clock was improved to below 2E-12τ1/2 up to 10'000s.