The Gaganyaan project seeks to demonstrate India's human spaceflight capability.
The Gaganyaan Mission, the country's maiden crewed spaceflight program, is expected to be launched by the end of 2026, with the rocket's first uncrewed test flight likely to be held early next year, Indian Space Research Organisation (Isro) Chairman S Somanath said on Monday.
The Gaganyaan project seeks to demonstrate India's human spaceflight capability by launching astronauts to an orbit 400 kilometres above the Earth for a three-day mission. After that, they will be brought back to Earth safely with a landing in Indian sea waters.
If the indigenous space project estimated to cost Rs 90 billion succeeds, India will become only the fourth country to send a human into space after the Soviet Union, the US and China.
Speaking to the media on the sidelines of an event at IIT-Guwahati, Mr Somanath said: "We have been working on the Gaganyaan project for the last four years. Our rocket is completely ready. The (first uncrewed test flight) launch is scheduled for early next year. We wanted to do it in December this year but due to technical difficulties, it is slightly getting extended."
The ISRO Chairman said three other launches will take place before the crewed flight towards the end of 2026. "Under the first launch, we will put a robot named Vyommitra inside. That launch will take place early next year. We will then have two more launches of similar nature. Once all the three launches are successful, we will have the crewed mission. All the astronauts are ready. We aim to launch Gaganyaan by the end of 2026," he said.
In February, Prime Minister Narendra Modi had announced the names of four astronauts, who are undergoing training for the human space flight mission. They are Group Captains Prasanth Balakrishnan Nair, Angad Pratap, Ajit Krishnan, and Wing Commander Shubhanshu Shukla.
Mr Somanath also spoke about Chandrayaan 4, the next giant leap in the Moon mission after the successful landing of Chandrayaan 3 in the lunar south pole in August last year.
"The Union government has already given its approval for Chandrayaan 4. Chandrayaan (4) will again go to the same point, that is the south pole. We will see how we can go there, take some samples and bring them back on earth. It will demonstrate two types of technology - one, bringing back the sample, and two, going to the moon and coming back," Mr Somanath said.
"But unfortunately, we do not have a rocket for that. The mass of the satellite to go to the moon is very high. To go to the moon, we need to do two launches, they (two satellites) will interlock in space," he added.
Mr Somanath also said it is for the first time that India will carry out such a mission. "No one has done anything like this before... So, we hope we will become the first country to do such a complex maneuver," he said.