Skudo is actively working on several ESA ( European Space Agency) projects to expand and bring our encryption technology to space applications. Within the scope of a contract with ESA, we implemented an asymmetric PKI that is compliant with the CCSDS Space Security Data Link protocols /SDLS). We demonstrated the functionalities of our hardware embedded HSM, in combination with the custom ESA PKI, on a strato balloon flying at 20-25Km in the sky, simulating the HAPS (High Altitude Pseudo Satellite) conditions, by demoing an end-to-end asymmetric encryption data link (CCSDS TC/TM) established between the ground and the balloon itself (via the SDLS protocol). The E2E encryption is based on digital certificates and asymmetric cryptography.