The Swedish PRISMA IRIDES experiment (Iterative Reduction of Inspection Distance with Embedded Safety) encompassed the transfer of the PRISMA MANGO spacecraft to the non-operational and un-prepared CNES PICARD spacecraft with close range rendezvous and inspection. The rendezvous and inspection phases were intended to be performed by on-ground calculated deltaV manoeuvers based on the available relative-navigation data. The intention of IRIDES was to support by in-orbit experiment the development of technology and strategies for space debris monitoring, remediation and on-orbit servicing.
Given this context, the objective of the ESA GSP study with OHB-SE, the operator of the PRISMA MANGO spacecraft, has been to perform guidance, navigation and control (GNC) analysis of the optimal phasing, far range rendezvous and the proximity maneuvers and to perform an operations assessment for the PRISMA IRIDES experiment in preparation for actual implementation and execution of the IRIDES experiment in the timeframe from August till November 2014. Study objectives included the assessment of AOCS sensor utilization, GNC mode selection, upgrade of image processing algorithms, assessment of collision risk, preparation of escape strategies for collision avoidance, and the overall analysis and plan-ning of the step-by-step maneuver sequence, leading to a safe fly-around down to 10m min-imum distance, only relying on the available resources on-board MANGO and on ground.