NEW DELHI: After an 18-day stay at the International Space Station (ISS), astronaut Shubhanshu Shukla and three others of the commercial Axiom-4 mission are setting off on a return journey to Earth on Monday.

Shukla, who became the second Indian astronaut to travel to space after Rakesh Sharma's 1984 odyssey, will board the Dragon spacecraft at around 2 pm IST and embark on the return journey two hours later.

"Undocking from the ISS is scheduled for no earlier than 6:05 am CT (4:35 pm IST)," Axiom Space said in a statement.

"After a 22. 5-hour journey back to Earth, the crew is expected to splash down off the coast of California at approximately 4:31 am CT (3:01 pm IST on Tuesday)," it added.

On Sunday, the Expedition's 73 astronauts organised a traditional farewell ceremony for the Axiom-4 crew comprising Shukla, commander Peggy Whitson, and mission specialists Slawosz Uznanski-Wisniewski of Poland and Tibor Kapu of Hungary.

The Axiom-4 mission marked the return to space for India, Poland and Hungary after over four decades.

"Jaldi hi dharti pe mulaqat karte hai (we will meet on earth soon)," Shukla said at the farewell ceremony onboard the ISS on Sunday.

The descent of the Dragon spacecraft from the ISS is designed to be completely autonomous.

After undocking, Dragon will perform a series of engine burns to safely distance itself from the ISS and begin re-entry procedures.

Final preparations include detaching the capsule's trunk and orienting the heat shield ahead of atmospheric entry, which will expose the spacecraft to temperatures nearing 1,600 degrees Celsius.

Parachutes will deploy in two stages -- first stabilising chutes at about 5.7 km altitude, followed by the main parachutes at roughly two km.

Splashdown is expected off the coast of California approximately 22.5 hours after undocking, and the space capsule will be recovered by a specialised ship.

Shukla recalled the time when his icon Rakesh Sharma had travelled to space 41 years ago and described how India looked from there.

"We all are still curious to know how India looks today from above. Aaj ka Bharat mahatvakanshi dikhta hai. Aaj ka Bharat nidar dikhta hai, Aaj ka Bharat confident dikhta hai. Aaj ka Bharat garv se purn dikhta hai.m(Today's India looks full of ambition, fearless, confident and full of pride)," Shukla said.

"It is because of all these reasons, I can say it once again that today's India still looks 'saare jahan se accha'," he said.

A formal farewell ceremony on the ISS on Sunday was marked by brief remarks by the tTAx-4x-4crew, some of whom appeared to have got emotional as they hugged members of the Expedition 73 with whom new friendships were forged during the stay.

"I didn't imagine all of this when I started on the Falcon-9 on June 25. I think it has been incredible because of the people involved.

People standing behind me (the Expedition 73 crew) have made it special for us.

It was an incredible joy to be here and work alongside professionals like you," Shukla said.

The four astronauts are expected to spend seven days in rehabilitation as they adjust back to life on Earth under the influence of gravity, unlike the weightlessness experienced in orbit.

It has been a historic trip for Shukla, who became the first Indian to travel to the ISS and only the second to travel to space after Sharma's pathbreaking spaceflight as part of the then Soviet Union's mission to Salyut-7 space station in 1984.

ISRO paid approximately Rs 550 crore for Shukla's travel to the ISS, an experience that will help the space agency in the planning and execution of its human spaceflight programme, Gaganyaan, set to take to orbit in 2027