New Delhi: Prime Minister Narendra Modi announced on Wednesday that India would send an astronaut into space before or by 2022, challenging India's space agency to pursue its first-ever manned space mission and setting a surprise target date.

The Indian Space Research Organisation (Isro) has developed and tested several critical technology components for a manned space mission for over a decade, but this is the first indication of the government's approval for a manned space flight.

"India has made progress in the space domain," Modi said, delivering his Independence Day speech at Red Fort. "But we have a dream, our space scientists have a dream. We have decided that by 2022, when India completes 75 years of Independence, or before that, a son or daughter of India will go into space with a Tricolour in hand."

Modi said India's Gaganyaanspacecraft would carry an Indian into space, making India the fourth country in the world with manned spaceflight capability. Russia, the US and China have so far sent astronauts into space aboard their own homegrown spacecraft.

Senior Isro officials said the agency had been preparing itself for manned space flight for more than a decade through the development of relevant technologies such as a space capsule, a giant rocket for heavy payloads, operational systems to recover space capsules from low-Earth orbit and a crew escape system.

The space agency has periodically updated the government on its progress towards these technologies.

"The target date (2022) is a surprise for us. But we are confident we can achieve this because we have already developed and tested most of the critical technologies," Kailasavadivoo Sivan, Isro chairman, told The Telegraph on Wednesday over the telephone.

The costs for a manned space flight are still to be worked out but, he said, Isro believes the project will cost less than Rs 10,000 crore. "The actual manned flight of the space capsule will be preceded by two unmanned flights," Sivan said.

The space agency will need to work with other government agencies, including the Defence Research and Development Organisation and the Indian Air Force, to execute the mission, the chairman said.

The Institute for Aviation Medicine, Bangalore, a unit of the IAF, has developed a human centrifuge and other facilities required to train would-be astronauts.

India's space programme, under policies set by its earliest architects, had for decades focused on ground applications of space. Isro rockets and satellites help support weather forecasting, telecommunications, broadcasting, education and telemedicine, and guide fishermen to bountiful catch.

But since the late-1990s, space policy-makers in India have believed the programme has matured to points where India needs to undertake space exploration missions and possibly manned missions. The lunar orbiter launched in 2008 and the Mars orbiter in 2014 were part of this changed policy.

"We've debated for long on the tangible and intangible benefits of manned space missions," said B.N. Suresh, former director of the Vikram Sarabhai Space Centre, Thiruvananthapuram. "Many of us believe manned space missions will help India's long-term interests. Such missions also have huge technology spin-offs and can inspire young people in the country towards science."

Former space officials also believe the capacity for manned space missions will prepare India to collaborate with other countries for future manned space programmes.

"We should engage with Nasa, the European Space Agency and even the Chinese to evolve the purposes of internationally collaborative humans-in-space programmes," said V. Siddhartha, a former senior space official.