Project CADISS has produced an elegant breadboard of a system for compression (and -if required- decompression) of signals generated by imaging sensors on-board scientific satellites. The performance, specifications and physical characteristics of CADISS are the result of trade-offs on function (algorithms), technology, through-put speed and cost. CADISS is a low-power, (micro) programmable multi-processor prototype system with interfaces to a Remote Terminal Unit (for downloading of software), to image data generating instruments and to the on-board formatter. This report describes the concept of CADISS, its algorithms, its technology and the test results. It should be noted that the design was frozen mid 1983, using technology which was state-of-the-art at that time.