Two small satellites that taught India to dock: what the Space Docking Experiment proved

Background

SPADEX stands for Space Docking Experiment. It was launched aboard the PSLV-C60 launch vehicle with two satellites, SPADEX-A and SPADEX-B, into a 470 km circular orbit. The mission demonstrated critical autonomous rendezvous and low-impact docking technologies. Both spacecraft completed their core objectives, which included vertical and radial docking, composite control, power transfer, undocking and payload operations, and circumnavigation was also demonstrated. The two satellites later re-entered the atmosphere after their fuel was exhausted, with orbital decay accelerated by two moderate geomagnetic storms; SPADEX-A came down over the South Pacific Ocean and SPADEX-B over the North Atlantic Ocean.