Two Indian astronauts, Group Captain Shubhanshu Shukla (Prime) and Group Captain Prasanth Balakrishnan Nair (Backup), have completed the initial phase of training for the Axiom-4 mission to the International Space Station (ISS), ISRO announced. The two Gaganyatris began their training in the USA in August 2024, as part of a joint ISRO-NASA effort for the mission.