ISRO is no stranger to being slapped with a deadline and then banding together to meet it. The Mars Orbiter Mission was completed and launched in just 18 months. However, the country's human spaceflight program has been in the works for well over a decade now. The original plan, as decided in 2004, was to develop a two-stage-to-orbit reusable vehicle by 2020. But despite an initial budget of ₹15,000 crores ($2.1 billion), the program did not materialise due to lack of funding from the then-central government.

Since then, ISRO has managed to develop in-house tech over the years that helped shave the budget down to ₹9000 crores ($1.3 billion).

In an interview aired just three days before Prime Minister Modi's address, Chairman Sivan said that much of the tech needed for human spaceflight is already in place.

Several critical program components have already been developed and demonstrated. The Environmental Control and Life Support System (ECLSS) is purportedly ready. The crew module atmospheric reentry and heat shield were successfully tested in 2014, after a launch atop the GSLV Mk III. The Crew Escape System (CES) and its parachutes were tested successfully this July in a Pad Abort Test at Sriharikota. ISRO has also developed a prototype for a spacesuit, in the traditional orange color, though there aren't any details available about the suit yet.

The GSLV Mk III itself has flown twice successfully, once suborbital and once to geostationary orbit. Sivan said human rating the vehicle can be easily achieved, as it is "more reliable, requires less number of components, and is over-designed."

"What is required is infrastructure within ISRO like control centres, launch pad modifications, building the actual vehicle, and creating the module," said Sivan. What ISRO also has seemingly not ventured into yet with solid prototypes or results are crew support systems.

The organisation plans to perform at least two uncrewed tests before sending three people to low-Earth orbit (300 to 400 kilometres), where they would stay for a week. The first of these tests is expected to take place in 2020.