NASA puts off Sunday's launch of Axiom-4 mission to International Space Station

NASA has put off Sunday's launch of the Axiom-4 mission carrying Indian astronaut Shubhanshu Shukla and three others to the International Space Station, saying it required additional time to evaluate operations on the orbital lab after the recent repairs in its Russian section.

The Axiom-4 mission was targeting a June 22 launch after being put off multiple times due to a leak in the boosters of SpaceX's Falcon-9 rocket, inclement weather in the ascent trajectory and leaks in the aft-most section of Zvezda service module.

The space agency needs additional time to continue evaluating the International Space Station operations after recent repair work in the aft (back) most segment of the orbital laboratory's Zvezda service module, it said.

Because of the space station's interconnected and interdependent systems, NASA wants to ensure the station is ready for additional crew members, and the agency is taking the time necessary to review data, the Axiom Space statement said.

Former NASA astronaut and director of human spaceflight at Axiom Space, Peggy Whitson, will command the commercial mission, while Shukla will serve as the pilot. The two mission specialists are European Space Agency (ESA) project astronaut Slawosz Uznanski-Wisniewski of Poland and Tibor Kapu of Hungary.

The 14-day mission will "realise the return" to human spaceflight for India, Poland and Hungary.

The astronauts were originally scheduled for lift-off on May 29, which was put off to June 8, June 10 and June 11, when SpaceX, the providers of the launch rocket and the space capsule, detected a liquid oxygen leak in the Falcon-9 rocket.

At a pre-launch press conference on June 10, SpaceX Vice President William Gerstenmaier said engineers had detected a liquid oxygen (LOX) leak on the Falcon-9 booster during the re-entry phase of its previous mission that was not fully repaired during refurbishment.

At the same press interaction, Dana Weigel, Manager of NASA's International Space Station Program, had said that launch opportunities were available till June 30.

In case SpaceX and Axiom Space are unable to launch in the month of June, there are opportunities from mid-July, she added.

The Axiom-4 crew has been in mandatory pre-launch quarantine since May 26.

The pre-launch quarantine is necessary to closely monitor the astronauts' health, avoid exposure to any last-minute illness and ensure that the astronauts flying to the space station don't carry any infection to the closed environment of the orbiting lab.