Undocking successful, Shubhanshu Shukla, Ax-4 crew begin 22-hr journey back home
The SpaceX Dragon C-213 spacecraft undocked from the International Space Station’s (ISS) Harmony module on Monday, marking the end of the 18-day Axiom Mission 4 (Ax-4) — the fourth private astronaut mission to the orbiting lab.
Group Captain Shubhanshu Shukla, who served as the mission pilot, made history as the first Indian to visit the ISS.
Also aboard the returning spacecraft are Ax-4 astronauts Peggy Whitson, Sławosz Uznański-Wiśniewski and Tibor Kapu. The crew had launched aboard Dragon atop a Falcon 9 rocket from NASA’s Kennedy Space Centre in Florida on June 25. The return journey to Earth will take approximately 22.5 hours.
“The spacecraft will return the crew and its cargo safely to Earth, targeting a splashdown off the coast of California on Tuesday, July 15,” NASA said in a statement.
The Dragon capsule is also carrying over 580 pounds of cargo, including NASA hardware and data from more than 60 experiments conducted during the mission.
During his time aboard the ISS, Shukla carried out several scientific experiments and outreach activities. The findings will be shared with Indian scientific institutions and applied to ISRO’s human spaceflight programme, Gaganyaan.
“Gaganyatri Shubhanshu Shukla successfully completed all seven planned microgravity experiments and other mission activities — a significant milestone,” ISRO said in a statement. “These included experiments on an Indian strain of tardigrades, myogenesis, sprouting of methi and moong seeds, cyanobacteria, microalgae, crop seeds and the voyager display.”
When the SpaceX Dragon spacecraft re-enters Earth’s atmosphere, the Ax-4 crew will experience intense g-forces, as well as thermal and physical stress — a phase they’ve been trained for at NASA’s Johnson Space Centre to help them transition from microgravity back to Earth’s gravity.
Re-entry will begin at an altitude of around 180 km, with the spacecraft’s exterior heating up to nearly 2,000°C due to atmospheric friction. Dragon’s heat shield, made from PICA-X — a carbon-based material — is designed to protect both the spacecraft and its crew from the extreme conditions during descent.
At about 5.5 km (18,000 ft), two drogue parachutes will deploy to stabilise and slow the spacecraft. These will be followed by four main parachutes around 6,000 ft, which will reduce the descent speed to 24 km/h (6-7 m per second), enabling a safe splashdown in the Pacific Ocean off the coast of California. Splashdown is expected around 3 pm IST on July 15.
A SpaceX recovery ship will be stationed near the splashdown zone. Small boats carrying specially trained technicians will approach the capsule first to conduct safety checks, inspecting for damage, radiation exposure, or contamination.
Once cleared, the Dragon capsule will be hoisted onto the recovery vessel. The crew will then disembark and recovery teams will secure the scientific cargo and equipment.
Initial medical evaluations and health checks will be conducted onboard. The astronauts will then be ferried ashore and transported to a secure NASA facility, where a comprehensive post-mission recovery process will take place.
This will include assessments of physical fitness (balance, reflexes, cardiovascular and immune function), psychological evaluations to gauge mental wellbeing and readjustment to Earth’s gravity and targeted rehabilitation exercises to restore strength and coordination.
India