Watch exclusive interview with Prof. Dipankar Banerjee, Director, IIST. Prof Dipankar Banerjee,decipher the Proba-3 mission. Proba-3 is an In-Orbit Demonstration (IOD) mission of the European Space Agency. The mission goal is to demonstrate precise formation flying. It consists of 2 spacecrafts and it will be launched together in a stacked configuration.