Boeing’s Starliner first crewed spacecraft to be piloted by Indian-origin astronaut Sunita Williams is expected to be launched between June 1 and June 5 after the flight was postponed earlier this month due to a technical snag.

Williams, 58, will fly into space for the third time aboard the test flight.

A statement from NASA said: "Mission managers from NASA, Boeing, and ULA (United Launch Alliance) continue to evaluate a path forward toward launching the agency’s Boeing Crew Flight Test to the International Space Station. The teams are now working toward a launch opportunity at 12:25 p.m. on Saturday, June 1, with additional opportunities on Sunday, June 2, Wednesday, June 5, and Thursday, June 6." Work continues to assess Starliner performance and redundancy following the discovery of a small helium leak in the spacecraft’s service module, the statement said.

It said teams were in the process of completing a follow-on propulsion system assessment to understand potential helium system impacts on some Starliner return scenarios.

Starliner will carry Williams and Butch Wilmore to the International Space Station, marking what could be a momentous and long-awaited victory for the beleaguered Boeing programme.

An attempt to launch the first crewed test flight for the International Space Station from Cape Canaveral in Florida was postponed on May 6 after a technical snag was discovered moments before the take-off.

NASA will also conduct a Delta-Agency Flight Test Readiness Review to discuss the work that was performed since the last CFT launch attempt on May 6 and to evaluate issue closure and flight rationale ahead of the next attempt as part of NASA’s process for assessing readiness, the statement said.

The statement said Williams and Butch Wilmore continued practising in Starliner simulators to prepare for flight, and the crew, which remains quarantined, will fly back to NASA’s Kennedy Space Centre in Florida closer to the new launch date.

The mission has been delayed for several years because of setbacks in the spacecraft's development.

If it is successful, it will become the second private firm able to provide crew transport to and from the ISS, alongside Elon Musk's SpaceX.

Such a scenario — with both SpaceX’s Crew Dragon and Starliner flying regularly — is one for which the US space agency NASA has long waited.

This is Boeing’s second flight to the International Space Station and third Starliner flight test overall, following a second Orbital Flight Test, the uncrewed mission also known as OFT-2, in May 2022.

Boeing also completed a pad abort demonstration in November 2019, according to NASA.

SpaceX and Boeing developed their respective vehicles under NASA’s Commercial Crew Programme, a partnership with private industry contractors. From the outset, the space agency aimed to have both companies operating at once.

The Crew Dragon and Starliner spacecraft would each serve as a backup to the other, giving astronauts the option to keep flying, even if technical issues or other setbacks grounded one spacecraft.

Williams received her commission as an Ensign in the United States Navy from the United States Naval Academy in May 1987.

Williams was selected as an astronaut by NASA in 1998 and is a veteran of two space missions, Expeditions 14/15 and 32/33.

She served as a flight engineer on Expedition 32 and then commander of Expedition 33.

While onboard, she established a world record for females with four spacewalks totalling 29 hours and 17 minutes. Astronaut Peggy Whitson subsequently broke the record in 2008 with a total of five spacewalks.

Williams spent four months conducting research and exploration aboard the orbiting laboratory.

Williams was born in Euclid, Ohio, to Indian-American neuroanatomist Deepak Pandya and Slovene-American Ursuline Bonnie (Zalokar) Pandya.

She holds a physical science degree from the US Naval Academy and a Master of Science in Engineering Management from Florida Institute of Technology.

Except for the headline, this story has not been edited by The Telegraph Online staff and has been published from a syndicated feed.