Just hours before Indian astronaut Shubhanshu Shukla was set to board the Dragon spacecraft for a landmark journey to the International Space Station (ISS), SpaceX announced a delay with no new launch date yet confirmed. The postponement stems from a liquid oxygen (LOx) leak detected during post-static fire booster inspections.
SpaceX tweeted on Wednesday, “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.”
Initially scheduled for May 29, the Ax-4 mission was pushed to June 8, then June 10, and later postponed to June 11 due to adverse weather conditions and high winds near the launch site.
What is Liquid Oxygen (LOx)?
Liquid oxygen is a supercooled, highly reactive form of oxygen stored at -183°C. It acts as an oxidizer in rockets, enabling fuel combustion in space, where atmospheric oxygen is absent. SpaceX’s Falcon 9 rocket uses LOx combined with RP-1, a refined kerosene, to power its Merlin engines. This mixture creates the intense thrust required to lift the rocket into orbit. Any LOx leak jeopardizes launch safety and can cause significant delays.
Details of the Leak and Its Impact
The LOx leak was discovered during a static fire test on June 9. The Falcon-9 booster involved had recently completed a mission launching Starlink satellites and was refurbished for the current Dragon spacecraft flight. SpaceX initially attempted to fix the leak by installing a purge system, but this solution proved ineffective.
Experts now suggest that the Falcon-9 booster may need to be removed from the launch pad and placed horizontally for thorough repairs, potentially causing a delay that could extend into the following week.
The Indian Space Research Organisation (ISRO) stated, “It is understood that LOX leakage was detected in the propulsion bay during the test. Based on the discussion between the Isro team and experts from Axiom and SpaceX, it has been decided to correct the leak and conduct necessary validation tests before clearing the launch. Hence the launch of Axiom-4 slated for 11th June 2025 for sending the first Indian Gaganyatri to ISS is postponed.”
As of now, SpaceX has not announced a new date for the Ax-4 mission.
