Shubhanshu Shukla: After 300+ orbits, 1.3 crore-km travel, Shubhanshu Shukla, Axiom-4 crew undock from ISS; splashdown at 3 pm July 15
BENGALURU: After completing more than 310 orbits covering 1.3-crore-km, 33 times the distance between Earth and Moon, Indian astronaut Shubhanshu Shukla and three other Axiom-4 (Ax-4) mission astronauts successfully undocked from the International Space Station (ISS) on Monday, marking the beginning of the 22.5-hour homeward journey.Monday marked the 20th day since the Ax-4 crew lifted off to space in the Dragon (Grace) capsule aboard the Falcon-9 rocket from the Kennedy Space Center on June 25. The crew docked with the ISS and entered the orbital lab nineteen days ago, on June 26. They would have seen over 300 sunrises and sunsets during their time at the station.By around 2.11 pm Monday, Shukla and mission commander Peggy Whitson were fully suited and in their seats inside Grace, while mission specialists Tibor Kapu and Slawosz Uznanski, also inside the capsule, were yet to suit up, which happened by 2.47 pm. At 2.50 pm the entire hatch closing process, which had started at around 2.38 pm, was complete. Following this, the Nasa and SpaceX teams began procedures for depressurisation of Grace and also conducted leak tests and other checks before the capsule could be given a go-ahead for undocking.By around 4.25 pm, mission control announced a 10-minute delay in undocking, waiting for a final “go, no-go”, which happened at 4.37 pm. Grace got the final undocking command at 4.40 pm and separated from the ISS at 4.45 pm.Following this, Grace — carrying more than 580 tonnes of cargo, including the 60+ experiments — performed the first departure burn at 4.46 pm for 16 seconds. The second departure burn (20 seconds) was carried out at 4.51 pm, following which the four astronauts got out of their space suits and got into “comfortable clothes” for the 22.5-hour journey.Minutes after the undocking, mission commander Peggy Whitson radioed “Godspeed” and hoped for a safe return to Earth. Including the first two, Grace was scheduled to perform four departure burns spread over 90 minutes to get away from the ISS and enter a new orbit. From there, the capsule is expected to maintain the orbit until well past noon on Tuesday. Ground teams are continuously monitoring Grace and will give multiple “go”, “no-go” commands until the de-orbit burn, scheduled for around 2.07 pm on Tuesday (July 15). Among other things, the teams will check for weather conditions to ensure that both the crew and the recovery teams are able to operate safely at the recovery site, off the coast of California.“Key weather parameters that teams will watch out for will be that there’s no rain or lightning at the recovery site. They would also look at the wind speed, which should not be more than 10 miles per hour,” an Axiom representative said.About 50 minutes after the de-orbit burn, Grace will deploy the drogue parachutes, a minute before deploying the main parachutes. As per the current plan, Grace is expected to splashdown off the coast of California at 3 pm on July 15. Upon splashdown, recovery teams will reach the capsule, perform safety checks, and prepare it for lifting onto the ship using a hydraulic cradle. Once this is complete, the first medical checks are completed, following which the crew is transported back to land on a helicopter and taken for further medical evaluations, mission debriefs, and recovery procedures. During their time at the ISS, the Ax-4 crew performed more than 60 experiments from 31 countries, including India, the US, Poland, Hungary, the UAE, among others. Seven of these were led by Isro.