2 delays in 2 days: What’s happening with Shubhanshu Shukla’s Axiom-4 mission?

Indian astronaut Shubhanshu Shukla’s much-awaited trip to the International Space Station (ISS) has faced another delay.

The Axiom-4 mission was earlier planned to launch from Nasa’s Kennedy Space Centre in Florida on June 10.

But bad weather led to a postponement, and the launch was pushed to Wednesday (June 11).

Now, it has been delayed once more. A new launch date has not yet been announced.

So, why has the mission been delayed again? When can we expect it to take off?

In this explainer, we answer these questions and take a closer look at the reasons behind the latest delay.

Why Axiom-4 (Ax-4) has been postponed again

The launch of the Axiom-4 mission , which was scheduled for June 11, has been delayed once again. This happened after a liquid oxygen (LOx) leak was found during checks carried out after a static fire test of the booster.

Standing down from tomorrow’s Falcon 9 launch of Ax-4 to the @Space_Station to allow additional time for SpaceX teams to repair the LOx leak identified during post static fire booster inspections. Once complete – and pending Range availability – we will share a new launch date pic.twitter.com/FwRc8k2Bc0

— SpaceX (@SpaceX) June 11, 2025

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“Standing down from tomorrow’s Falcon 9 launch of Ax-4 to allow additional time for SpaceX teams to repair the LOx leak,” SpaceX said in a statement.

The Indian Space Research Organisation (Isro), posting on X, confirmed that the LOx leak was spotted in the propulsion bay during a test. The leak involves a problem with the oxygen used in the launch system.

Postponement of Axiom 04 mission slated for launch on 11th June 2025 for sending first Indian Gaganyatri to ISS.

As part of launch vehicle preparation to validate the performance of booster stage of Falcon 9 launch vehicle, seven second of hot test was carried out on the launch…

— ISRO (@isro) June 11, 2025

“Based on the discussion on this topic by Isro team with the experts of Axiom and SpaceX it has been decided to correct the leak and carry out necessary validation test before clearing for the launch,” the agency added.

Notably, Isro has partnered with Nasa and SpaceX for the Axiom-4 mission. The aim is to carry out several custom-designed experiments aboard the ISS, which will contribute to India’s future space efforts.

This is not the first delay. The launch was earlier moved from June 8 to June 10 due to poor weather.

Initially, Axiom Space had planned the takeoff for May 29. It was then shifted to June 8 to align with changes in the ISS schedule.

But what exactly happened with the oxygen leak? And where is the liquid oxygen normally stored?

What we know about the oxygen leak and technical issue

In space missions, timing is everything. Since the ISS and other objects in space are constantly moving, a launch cannot happen at just any moment. The alignment of orbits plays a key role, and scientists carry out detailed calculations to ensure the spacecraft’s path matches the path of the ISS.

For missions headed to the ISS, rockets usually circle the Earth several times before catching up with the station. This route also helps manage the amount of fuel needed.

The rocket being used has two stages. According to a report by The Indian Express, the first stage contains nine Merlin engines and tanks made from aluminium-lithium alloy, which hold liquid oxygen and rocket-grade kerosene. The second stage includes one Merlin engine.

This is why the oxygen leak has caused concerns. It was detected in a part of the rocket that is crucial for launch. So, any problem with its storage or flow needs to be fixed fully before the mission can go ahead.

What Isro chief said on the mission’s delay

Speaking to NDTV, Isro chairman Dr V Narayanan, who is also an expert in liquid engines, said that the decision has been made to fix the leak and carry out the required validation tests before giving clearance for the launch.

“The emphasis on carrying out necessary validation is typical of Isro’s rocket flying culture,” he told the media outlet.

He added that delaying the launch was a “good decision”, especially because human lives are at stake.

Notably, Dr Narayanan has been an important figure in the development of India’s cryogenic engine, which uses liquid oxygen and liquid hydrogen as fuel.

Axiom-4 mission: What is it? Who are the crew members?

The Axiom-4 mission will see its crew carry out nearly 60 scientific experiments during their stay aboard the International Space Station.

According to Axiom Space, the research has been specially designed to be conducted in microgravity and is being carried out for organisations across the world.

Indian astronaut Shubhanshu Shukla will focus on food and nutrition-based experiments developed in partnership with the Indian Space Research Organisation (Isro) and the Department of Biotechnology (DBT), with support from Nasa.

These experiments aim to explore ways to improve space nutrition and create self-sustaining life support systems, both of which are crucial for future long-term missions in space.

The mission crew includes Commander Peggy Whitson, along with specialists Tigor Kapu from Hungary and Slawosz Uznanski-Wisniewski from Poland, apart from Shukla.

This journey will mark India’s return to human spaceflight after 41 years. The last Indian in space was Rakesh Sharma, who flew aboard Soviet Russia’s Soyuz spacecraft in 1984.

When will Axiom-4 launch next?

After multiple delays and a technical snag, SpaceX confirmed it is “standing down” from the planned Falcon 9 launch of Axiom-4.

The company added that a new launch date will be shared once the required repairs are completed.

“Once complete – and pending Range availability – we will share a new launch date,” SpaceX said.

With inputs from agencies