C3PO: advanced Concept for laser uplink/ downlink CommuniCation with sPace Objects represents a radical improvement in performance of existing ground to low earth orbit communication systems in terms of weight reduction, on-board power consumption, data rate and communication security & confidentiality. C3PO in figures:- Mass reduction by a factor 14- On-board power consumption reduction by a factor 100- Data rate increase by a factor 2The project's objectives are to- Design a solution to improve actual downlink and uplink communication systems based on a non-space disruptive technology- Improve enabling Space Surveillance & Tracking technologies performances to meet the final system needs- Increase the Multiple Quantum Well Technology Readiness Level from 2 to 4- Improve the overall perfromance of space communication systems- Identify the C3PO system market and Business Model - Increase the system safety (including regulation and governance issues)This is achieved through an operational analysis of the final system, the validation of major system parameters through 2 experiments, the consolidation of the system architecturen the elaboration of the associated development roadmap and the definition of the system Business Model. The Multiple Quantum Well retro-reflector technology, derived from non-space domain, is incorporated into the current state of the art as a high-rate lightweight communication device. Its development in the space sector has a disruptive impact on the satellites and satellite imagery markets, enabling new missions such as CubeSat earth observations.The proposed project serve the Union's Common Security & Defence Policy by increasing the satellite communications security.C3PO mobilises traditional space actors and non-space actors such as TEMATYS (SME) and ACREO (Research).