Sunita Williams stuck on ISS for over 2 weeks: What is causing the delay?

Nasa has delayed the return of the Boeing Starliner spacecraft from the International Space Station as the space agency wants to conduct additional reviews of the spacecraft's technical issues

Indian-American astronaut Sunita Williams and her colleague, astronaut Butch Wilmore, are stuck at the International Space Station (ISS).  According to US space agency Nasa, the return of the Boeing Starliner spacecraft has been postponed due to multiple technical issues.

Nasa has decided to conduct additional reviews of the spacecraft’s technical problems before permitting its return to ensure the safety of the astronauts.

Initially planned to return on June 13, the astronauts’ departure has been postponed several times. The agency has now not given any date for their return.

After multiple delays, Sunita Williams alongside US astronaut Butch Wilmore departed for the International Space Station aboard Boeing’s Starliner on June 5.

Delay in safe return to earth

The delay is attributed to several helium leaks discovered on Boeing’s Starliner spacecraft during its first crewed mission to the ISS. Engineers from Boeing and Nasa are actively addressing the problem to guarantee the astronauts’ safe return.

Nasa has reported that the spacecraft is “performing well in orbit while docked to the space station”.

The space agency further said that astronauts Wilmore and Sunita Williams can undock from the space station and return to Earth if needed. They are not “stranded”, but are staying in orbit beyond their scheduled return to allow mission teams adequate time to analyse propulsion system data.

Sunita Williams and Butch Wilmore (Photo: Nasa)

US-based Newsweek quoted Nasa’s Commercial Crew Programme manager Steve Stich as saying, “We are taking our time and following our standard mission management team process.”

“We are letting the data drive our decision-making relative to managing the small helium system leaks and thruster performance,” he added.

So, what if the Starliner’s thrusters fail to perform? If the thrusters malfunction during the spacecraft’s return trip, it could potentially leave Sunita Williams and her crew stranded in space.

First crewed flight of Boeing’s Starliner

As part of Nasa’s Commercial Crew Programme, this mission represented the first manned journey for the Starliner spacecraft. Its objective was to thoroughly assess the spacecraft’s performance across all phases — from launch and docking to its safe return to Earth in the western United States. Following a successful manned test flight, Nasa will proceed with the final steps to certify Starliner and its systems for upcoming crewed missions to the space station.

Inside the International Space Station | Photo: NASA

The mission has experienced considerable setbacks over time, coinciding with a difficult phase for Boeing due to safety issues within its commercial aviation sector.

Previous delays in Boeing's mission

In 2019, an initial unmanned test flight of a capsule veered off course due to a software malfunction, preventing it from reaching the ISS. According to Nasa, Boeing's insufficient safety checks were to blame for the failure.

In 2021, a launch attempt was delayed because of blocked valves. Following this, in May 2022, the capsule successfully docked with the ISS during an unmanned mission. However, subsequent issues arose, including concerns over parachutes and flammable cabin tape. These challenges caused further delays in the crucial crewed test flight needed to certify Starliner for regular Nasa missions to the ISS.