New Delhi | Shubhanshu Shukla and three other astronauts of the Axiom-4 entered the Dragon Grace spacecraft on Monday and were suited up to begin their journey back to Earth after an 18-day stay at the International Space Station.

Shukla, the mission pilot, commander Peggy Whitson, and mission specialists Slawosz Uznanski-Wisniewski of Poland and Tibor Kapu of Hungary entered the Dragon Grace spacecraft and donned their space suits for the 22.5-hour journey to Earth.

The hatch of the Dragon Grace spacecraft that connected it to the International Space Station was closed at 2:37 PM IST and the crew members were performing final checks before undocking from the orbital laboratory at 4:35 PM IST.

The departure procedures were streamed live from the space station by NASA.

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.

The splashdown is expected to take place off the coast of California at 3:01 pm IST on Tuesday.

The Axiom-4 mission began their space odyssey on June 25 when the Falcon-9 rocket carrying the Dragon space capsule blasted off from Florida towards the ISS.