Accompanied by Kerala Governor Arif Mohammed Khan, Chief Minister Pinarayi Vijayan, and Minister of State for External Affairs V Muraleedharan, PM Modi also assessed the progress of ISRO's Gaganyaan human spaceflight programme.

The inaugurated projects include the Trisonic Wind Tunnel at VSSC, the Semi-Cryogenic Integrated Engine and Stage Test Facility at ISRO's propulsion complex in Mahendragiri, Tamil Nadu, and the PSLV Integration Facility at the Satish Dhawan Space Centre (SHAR) in Sriharikota, Andhra Pradesh.

These projects, developed at a combined cost of approximately Rs 1,800 crore, enhance India's technical capabilities in the space sector and contribute to its growing stature as a spacefaring nation.

The Trisonic Wind Tunnel at VSSC enables the evaluation of aerodynamic characteristics and designs of rockets and aircraft by producing controlled airflow at speeds ranging from subsonic to supersonic, up to four times the speed of sound (Mach number 4.0).

The Semi-Cryogenic Integrated Engine and Stage Test Facility in Mahendragiri is a state-of-the-art facility designed to handle large propellant flows, standing at a height of 51 meters with a flame deflector depth of 30 meters.

The PSLV Integration Facility at Sriharikota includes various infrastructure components such as Integration Building, Service Building, and Rail Track, aimed at increasing launch frequency from the First Launch Pad (FLP).

PM Modi, alongside reviewing progress of Gaganyaan mission, also unveiled the names of four astronauts who are going to be the part of India's maiden human space flight mission.

The four astronauts--Prashanth Balakrishnan Nair, Angad Prathap, Ajit Krishnan, and Shubhanshu Shukla--will be participating in the mission Modi said.

PM Modi bestowed 'astronaut wings' to the four at the Vikram Sarabhai Space Centre (VSSC) at Thumba near Thiruvananthapuram.