Samudrayaan mission set to explore ocean bed by 2025-end, the earth sciences minister Kiren Rijiju has said.

The minister's announcement soon came after an underwater acoustic telephone, developed by National Institute of Ocean Technology (NIOT) for the submersible project, was successfully tested on March 9 at a depth of about 500 metres in the Bay of Bengal.

The ministry, in a tweet, said, "Underwater acoustic telephone indigenously developed in-house by MSS Group of MOES NIOT for manned submersible has been successfully tested up to 500 meters depth in BoB (Bay of Bengal) on board Sagar Manjusha (research vessel). Deployment preparation, operation and functional testing of underwater acoustic telephone was successfully conducted."

Similar to the Gaganyaan mission in which 2-3 astronauts will be sent to space in 2025, India will send its scientists to study the deep ocean 6,000 metres in its own Samudrayaan by the end of next year. India's deep-ocean submersible, 'Matsya6000', which will take scientists into the depth of the ocean, is "well on course" and could be tested by the "end of this year", Rijiju said in an interview to a news agency. The minister said he has reviewed the project and scientists should be able to carry out the first shallow water testing by 2025-end.

The project was initiated in 2021. The submersible will be equipped with a suite of scientific sensors and tools, and have an operational endurance of 12 hours, which is extendable up to 96 hours in the event of an emergency. So far, countries like the US, Russia, China, France and Japan have carried out successful deep-ocean crewed missions. If the country's deep-ocean mission is successful, it will put India in an elite club of nations that have the technology and vehicles to carry out undersea activities.