While it might seem surprising that returning from just 400 kilometers above Earth takes nearly a full day, the extended duration is a result of complex orbital mechanics, safety protocols, and precise landing requirements.
When Indian astronaut Shubhanshu Shukla and his Axiom-4 crewmates undocked from the International Space Station (ISS) on July 14, 2025, they began a carefully planned 22.5-hour journey back to Earth.
While it might seem surprising that returning from just 400 kilometers above Earth takes nearly a full day, the extended duration is a result of complex orbital mechanics, safety protocols, and precise landing requirements.
Unlike simply descending straight down, the Dragon spacecraft must first perform a series of engine burns to safely distance itself from the ISS and enter a slightly different orbit. This manoeuvre prevents any risk of collision with the station and initiates what engineers call “free flight,” during which the spacecraft orbits Earth independently for several hours before re-entry begins.
The timing of the deorbit burn, the critical engine firing that slows the capsule enough to begin atmospheric re-entry, is carefully calculated to align with the rotation of Earth and the position of the designated splashdown zone off the coast of California.
Since the ISS orbits Earth at roughly 28,000 km/h, the spacecraft must wait for the right orbital position to ensure a safe and accurate landing.
During re-entry, the Dragon capsule faces extreme heat, with temperatures nearing 1,600 degrees Celsius. To protect the crew and spacecraft, the descent is gradual and carefully controlled.
Parachutes deploy in two stages—first stabilising chutes at about 5.7 km altitude, then main parachutes at around 2 km—to slow the descent for a safe ocean splashdown.
Weather conditions and recovery ship availability also influence the timing. If conditions at the primary landing site are unfavourable, the spacecraft may remain in orbit longer before initiating re-entry.
