The story up to now: On June 10, Axiom Space introduced that the launch of its Axiom-4 mission to the International Space Station (ISS) can be postponed indefinitely. The mission crew included India’s astronaut-designate Shubhanshu Shukla, who — if the rocket had lifted off as deliberate — would have turn into the first Indian in earth orbit after 40 years and the first Indian onboard the ISS.
What is the Axiom-4 mission?
The Axiom-4 mission is the fourth mission deliberate by US-based spaceflight firm Axiom Space to the ISS. It consists of a crew of 4 folks — Peggy Whitson, Shubhanshu Shukla, Sławosz Uznański-Wiśniewski, and Tobir Kapu — plus cargo.
To facilitate the mission, NASA had contracted Axiom, which in flip had contracted the Falcon 9 rocket and the Dragon crew capsule for the mission from SpaceX. The mission is industrial in nature and isn’t a part of the common resupply missions NASA undertakes to the ISS.
Following an announcement to strengthen India-US ties in 2023, the Indian Space Research Organisation (ISRO) spent greater than Rs 500 crore for Mr. Shukla to fly on the mission. Mr. Shukla is one in every of the 4 astronaut-designates for ISRO’s forthcoming Gaganyaan human spaceflight mission. His compatriot Prasanth Nair is a part of the Axiom-4 backup crew.
Why was the launch referred to as off?
Ahead of Thursday’s flight, SpaceX had examined one in every of the rocket’s engines as a matter of process and found it was leaking liquid oxygen (LOX). LOX is a cryogenic gasoline, that means it must be saved at an especially low temperature. If LOX is uncovered to hotter circumstances, the oxygen will flip into fuel and never be usable as gasoline (because it’s very tough to pump gases).
Falcon 9 engines combust a mixture of rocket-grade kerosene and LOX to generate thrust, that means a LOX leak is a severe situation. The Axiom-4 mission had first been scheduled for liftoff on May 29 however needed to be postponed to June 8, June 10, and June 11. There was a back-up launch window on June 12. The delays have been a results of a mix of unfavourable circumstances associated to the climate and the launch car.
The crew thus continues its wait.
Why has no new date been introduced?
Since a LOX leak is a severe situation, SpaceX wants to search out the exact supply of the leak and why the underlying part(s) failed. How a lot time this can take is unclear. There are additionally specific launch ‘windows’ (particular moments in time) when a launch can ship the crew to the ISS with minimal gasoline and vitality use, together with the period of time the crew capsule shall be uncovered to daylight and generate solar energy with out overheating.
But as a result of the ISS is so near the earth, launch home windows seem extra often than these for the moon or Mars. NASA has already indicated there are extra alternatives by way of June and July.
Other elements that have an effect on the suitability of a launch window embody time on the launch pad for liftoff and entry to free docking ports on the ISS. The US’s NASA, Russia’s Roscosmos, and (much less usually) another house companies additionally ship missions to the ISS and must plan when and for the way lengthy their capsules are docked.
How arduous is it to repair a LOX leak?
When it leaks, LOX flashes to an invisible vapour nearly immediately and will be blown away by winds or followers close by. Detecting it usually entails time-consuming, labour-intensive work.
Many joints in the elements related to storing and pumping LOX are insulated with foam or are situated in nooks, that means many common leak-detecting strategies can’t bodily attain them. Materials contract at cryogenic temperatures (round 90 Okay), so a gap might seem closed at ambient temperature however open at cryogenic temperatures. So as soon as a gap has been fastened, engineers might must repeat assessments at each heat and chilly circumstances or check with liquid nitrogen to imitate working circumstances. Testing with LOX itself will be hazardous.
Fortunately specialists have been working with cryogenic engines for lengthy sufficient to know which instruments to make use of and which processes to comply with as soon as the leak has been recognized. They embody visible inspection, bubble assessments, helium signature assessments, flow-meter assessments, ultrasonic microphones, and thermal imaging.
Published – June 12, 2025 09:00 am IST
