Shubhanshu shukla axiom-4: India’s Group Captain Shubhanshu Shukla has started a historic journey of space on 25 June 2025 under the Akiom Mission-4 (AX-4). He has left for the International Space Station (ISS). The mission was launched from NASA’s Kennedy Space Center in Florida, USA through Falcon 9 rocket and dragon spacecraft.
But one question is that when ISS is just 400 km from Earth, then why does it take 28 hours to reach there? Let us understand the easy answer.
Why is the process of meeting ISS in space complicated?
ISS makes a round of the Earth every 90 minutes in “Low Earth Orbit”, about 400 km above the surface of the Earth, that is, it is moving at a speed of 28,000 kilometers per hour.
Instead of transporting the dragon vehicle directly to ISS, first it has to be adjusted slowly to his class so that it can match the direction, height and speed of ISS. This process is called Phaasing Manoeuvres, in which the vehicles of the vehicle are repeatedly burnt so that the orbit can be gradually changed.
SpaceX’s dragon vehicle uses 16 “DRACO thrusters” during this period, which produce 90 pounds in space.
Docking and security check takes extra time
When the dragon reaches ISS, its speed becomes very slow so that it can connect to the station safely. This docking process is very accurate because even a little lapse can cause an accident.
After docking, the equality and leakage of pressure between spacecraft and ISS is examined for about 1 to 2 hours. Only then can the passengers inside the vehicle enter the station.
Why Soyuz Tej and Why Dragon Slow?
The Russian Soyuz vehicle takes just 8 hours to reach ISS, as it is based on decades old technology and precise calculations. At the same time, SpaceX’s dragon vehicle is a new technology, which was first prepared for flights including unmanned and later humans in 2012.
SpaceX for dragon’s phazing and docking is still working on a new model of calculations and manuvers, which makes the time look a little more.
Launch delay and launch window role
The date of the AX-4 mission was changed several times. This launch proposed in May was postponed till June. The reason was bad weather, oxygen leakage in Falcon 9 rocket and maintenance in the Russian part of ISS.
The launch window is a certain time when it is necessary to leave the rocket so that it can reach ISS in low fuel and time. A little delay also re-schedules the entire mission.
How does the rocket work?
- Falcon 9 rocket works in two stages.
- The first stage transmits the vehicle out of the atmosphere with nine merlin engines and then lands back to Earth.
- The second stage, which has a merlin engine, installs the dragon vehicle into its orbit.
- This two-level process also makes the journey long, but it is better for both environment and cost.
Full timeline of travel
Launch: 25 June 2025, 12:01 pm (Indian time)
Admission to class: 15 minutes after launch
Zero Gravity Indicator: A small goose toy called “Joy” will start swimming in space
Phazing Manuvaras: In the next 28 hours, the vehicle will gradually reach ISS orbit
Docking: between 4 to 10 pm (IST) on 26 June
Pressure and leakage check: 1-2 hours after docking
ISS admission: Shubhanshu and team will enter the station after investigation
What is the role of Shubhanshu Shukla?
Group Captain Shubhanshu Shukla is the pilot of this mission. They are working with Mission Commander Pagi Whitson (former NASA astronaut). Their responsibilities include operating spacecraft, monitoring system and assisting in scientific experiments. He will stay on ISS for 14 days and will do 7 Indians and 5 American experiments. Apart from this, he will also organize special sessions related to yoga and Indian culture.
Delay and challenges
The AX-4 mission was postponed several times, sometimes the weather was bad, sometimes technical fault came and sometimes the Russian part of ISS was maintained. This shows how sensitive the space missions are and how high the value of every second is. Security, calculation, and accuracy- this is the real challenge of space.