CAPE CANAVERAL (FLORIDA): When India’s Shubhanshu Shukla and his three crewmates lift off aboard the Axiom-4 (Ax-4) mission on June 10, they’ll travel in a previously used SpaceX’s Falcon-9 rocket and a new Dragon spacecraft—the crew will give it a name in the coming days. But the journey from the launch pad to the International Space Station (ISS), where they’ll spend up to a fortnight, is a finely choreographed sequence of events that plays out over 28 hours. TOI explains how:
Ready for liftoff
The process begins at the historic Launch Complex 39A at Nasa’s Kennedy Space Centre in Florida. To refresh your memory, this is the complex from where Neil Armstrong lifted off to land on Moon!Hours before launch, the four Ax-4 astronauts, suited in custom flight gear, are driven to the pad and board the Dragon capsule—right now designated as “C213”. Once inside, they complete a series of pre-launch checks alongside teams from SpaceX and Nasa.Roughly 35 minutes before liftoff, Falcon-9’s fuelling begins post clearance from the Launch Director and once the crew’s emergency escape system is powered on. Rocket is loaded with supercooled liquid oxygen and RP-1, a highly refined rocket-grade kerosene. Dragon switches to internal power at T-5 minutes. By the time the countdown reaches zero, every system must be in perfect alignment.
Launch & ascent
As the clock approaches T-0, Falcon-9’s nine Merlin engines roar to life, lifting the rocket off the pad and into the sky. In just over a minute, it surpasses the speed of sound. At around 57 seconds into flight, it passes the phase known as “Max Q”—the point of maximum aerodynamic pressure on the vehicle. It’s one of the most critical moments where the rocket endures its peak mechanical stress.The climb continues as the rocket steers itself along a precise path to low-Earth orbit (LEO). The crew inside Dragon experience increasing g-forces as Earth’s gravity fights their upward momentum.
First stage separation
Approximately two-and-a-half-minutes after launch, the main engines shut down, and the first stage — the lower part of the rocket — will separate. This stage has done its job and now heads back to Earth. Using cold gas thrusters and grid fins, it manoeuvres for a vertical landing on a floating drone ship stationed in the Atlantic Ocean.Meanwhile, the second stage engine ignites, pushing Dragon even higher and faster. Atop this stage, the capsule remains attached until it reaches a stable orbit.
Entering orbit
About 10 minutes after liftoff, Dragon separates from the second stage. Now in orbit, the spacecraft begins flying on its own. Its nose cone opens to reveal navigation instruments and docking sensors, essential for the next phase: catching up with the space station.Dragon is now travelling at more than 27,000 km/hr, circling Earth roughly once every 90 minutes. But the ISS is not in the same orbit just yet, and getting there requires a series of carefully-timed manoeuvres.
Chasing the space station
The journey to the ISS is not a straight line. It’s more like a gradual orbital ballet. Over the course of the next 20 to 24 hours, Dragon executes a series of engine burns using its onboard thrusters. These raise and adjust its orbit, allowing it to phase into alignment with the space station’s path.These manoeuvres are planned down to the second. Even a slight delay could affect the rendezvous window. Dragon uses GPS data, radar, and its own sensors to continuously track both its position and that of the ISS.
Final approach & docking
Once Dragon is within range, it begins a slow and measured approach. It halts at several pre-set points —called waypoints — starting from 400 metres out and moving progressively closer. At each stage, ground controllers and onboard systems assess whether to proceed.At around 20 metres, Dragon makes its final approach. Using a suite of laser-based sensors and cameras, it aligns precisely with the docking port on the station’s Harmony module. The spacecraft then moves forward at just a few centimetres per second until it makes contact.The first stage is a soft capture, where magnets gently pull the capsule into position. This is followed by a hard capture: mechanical latches and hooks secure the spacecraft, and a pressure-tight seal is formed between Dragon and the ISS.
Welcome aboard
With docking complete, the crew is not immediately allowed to exit their vehicle and enter the station. Engineers on the ground conduct a series of leak checks and confirm that the pressure inside the docking vestibule is stable. Once verified, the hatches between Dragon and the ISS are opened.The Ax-4 astronauts then float into the space station, greeted by its current residents. Over the next two weeks, they will conduct a range of scientific experiments, including biomedical studies that could inform treatments for diseases like diabetes. For Shukla, the mission pilot, it marks not just a personal milestone but a proud moment for India’s expanding role in global space exploration.
