Intervention by India team before Axiom-4 launch helped identify oxidiser line crack: ISRO chairman

The first launch was deferred to June 8 due to an electrical issue in the SpaceX Dragon spacecraft — the module where the crew was seated. But on June 8, when the engines were test-fired on ground, an oxygen leak was observed in addition to an anomaly in one of the actuators, used in controlling the direction of the rocket’s thrust.

Dr Narayanan told The Indian Express that the oxygen leak was deemed minor and unlikely to affect the launch, but the Indian team — 18 scientists including the ISRO chairman and the director of the Human Space Flight Centre — embedded with the Axiom-4 and NASA teams felt something was amiss and pushed for further checks.

“Initially the team thought that there was a minor leak and the mission could proceed as planned. But, the Indian team insisted that proper checks be carried out even if it meant delaying the mission. And it was good that the tests were carried out because a crack was detected, allowing for repair. It was resolved before the mission took off,” Dr Narayanan said.

The crack was in the oxidiser line, which carries liquid oxygen to power the rocket — a serious safety risk, especially for a crewed mission.

The crack and other issues were fixed, but on June 12 NASA announced it was working with Russian space agency Roscosmos to evaluate a leak in the Zvezda module, the Russian-built service module of the ISS that houses key life-support and docking systems. This further delayed the mission until the final launch two weeks.

During the mission, the Indian team was present at both Kennedy Space Center in Cape Canaveral where launch operations took place and at mission control in Houston, Texas, where real-time flight operations are managed — from crew health monitoring and communications to emergency response.

Dr Narayanan described the mission as a significant step forward for ISRO’s human spaceflight programme, with astronaut training emerging as its single most valuable takeaway. He said Indian scientists got hands-on exposure to how crewed missions are run — from making real-time decisions and interpreting telemetry data to monitoring astronaut health and responding to in-flight contingencies.

“It was like a classroom where we learnt a lot by working with the other teams there,” he said. “The experience was important for understanding how human space missions are run at an operational level… The training of the astronaut — especially with someone as experienced as the commander — was a big learning experience for the Indian team.”

Axiom-4 commander Peggy Whitson, a veteran astronaut, holds the record for the most number of days spent in space by an American or a woman — 695 days across multiple missions.

India plans to build a sustained human spaceflight programme, with a space station targeted by 2035 and a human Moon mission by 2040. This will require setting up a permanent astronaut corps and regularly training new astronauts, like NASA and Roscosmos do.

In addition to the training, Dr Narayanan said Shukla’s experience of living in microgravity, staying in an isolated environment and returning to Earth would be invaluable for India’s own programme. ISRO has asked Shukla to document his entire experience in detail.

“This,” Dr Narayanan said, “would become teaching material for his fellow astronauts as well as the other astronauts to come.”

Shukla, who returned to Earth with a splashdown on July 15, is currently undergoing reconditioning in the United States. He is expected to remain in quarantine until the first week of August, after which he will participate in a debriefing with NASA and return home by mid-August.