SPADEX or Space Docking Experiment is a twin spacecraft mission being developed by Indian Space Research Organisation to mature technologies related to orbital rendezvous, docking, formation flying and remote robotic arm operations, with scope of applications in human spaceflight, in-space satellite servicing and other proximity operations. SPADEX campaign would consist of two IMS-2 class (400 kg) satellites, one would be Chaser and other being Target and both would be launched as co-passengers or auxiliary payloads. Both spacecraft would be injected into slightly different orbits.