Explained: How SpaceX's Crew Dragon will bring Shubhanshu Shukla and crew back to Earth

The Print

2 days ago

As part of the Axiom-4 mission, a private human spaceflight led by the US space company, Axiom Space, Indian Air Force group captain Shukla reached the ISS on 26 June, becoming the first Indian to set foot in the facility.
'After performing a series of departure burns to move away from the space station, Dragon will conduct multiple orbit-lowering manoeuvres, jettison the trunk, and re-enter Earth's atmosphere for splashdown off the coast of California 22.5 hours later,' SpaceX said in a statement Monday.
New Delhi: After a stay of nearly 20 days in the International Space Station (ISS), the Axiom-4 crew, including India's Shubhanshu Shukla, is set to return to Earth Tuesday. After undocking from the ISS, SpaceX's Grace—its latest Crew Dragon capsule—will begin a nearly 23-hour journey back to Earth, making a splashdown off the California coast.
While the initial plan was a 14-day stay, the return of the Ax-4 crew was rescheduled last week for 14 June. During his stay at the ISS, Shukla led seven experiments developed by Indian research institutions, while also participating in over 60 scientific experiments in microgravity conditions.
ThePrint explains Grace's journey and splashdown.
The return
SpaceX's Dragon, which was christened 'Grace' by mission commander Whitson just minutes after Ax-4 launch on 25 June, is scheduled to make a splashdown around 3.01 pm (IST) on Tuesday.
Axiom Space spokespersons explained that during its return, Grace will attain an orbital speed of about 2,816 kmph (17,500 mph). On its way, a series of parachutes will be deployed to slow it down, first to about 480 kmph and then to about 25 kmph, before it makes a controlled splashdown.
On Monday, after a round of system checks, the capsule was prepared for an autonomous undocking. After this initial process was completed, the Crew Dragon separated from the ISS, beginning a series of thruster burns to separate from the space station, with each burn the craft will move further away from the station before entering an orbit for reaching Earth.
Between Monday evening and Tuesday, SpaceX's capsule will be conducting different phases of the orbital phasing manoeuvres.
Closer to making a re-entry, Crew Dragon will jettison its trunk section and prepare to carry out the most critical manoeuvre—the deorbit burn.
During a deorbit burn, a spacecraft fires its engines to slow it down and initiate a descent from its orbit into the Earth's atmosphere. The controlled deceleration of the spacecraft is a crucial step in ensuring a safe atmospheric re-entry.
Once Dragon begins the process of entering the Earth's atmosphere, it will experience intense friction, which is expected to heat up the exterior of the craft to about 2000 degrees Celsius. The exterior of the capsule is coated with alloys that can withstand such high temperatures, keeping the crew inside safe.
After attaining peak heating, Dragon will progressively slow down. At a distance of about 5,000 metres from the splashdown site, the capsule will deploy two drogue parachutes, which will help stabilise it. Finally, four more parachutes will be deployed to bring down the descent speed to a safe range.
The module will then splash down in the waters, from where it will be recovered.
After being safely removed from the capsule, Shukla and his crewmates will have to undergo medical checkups and acclimatisation of at least 10 days.
Since SpaceX's Crew Dragon uses the latest technology, nearly all of the descent process will be automated. However, in case a system fails and manual intervention is required, Shukla will have to step in to take control as the designated mission pilot.
(Edited by Viny Mishra)
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