Nasa begins final countdown of Sunita Williams & Butch Wilmore's return

The Boeing Starliner needs to be undocked from the International Space Station to accommodate the Crew-9 mission set to launch no earlier than August 18

The US’s National Aeronautics and Space Administration (Nasa) is under intense pressure with a crucial 19-day deadline to ensure the safe return of astronauts Sunita Williams and Butch Wilmore from the International Space Station (ISS) following technical difficulties with their Boeing Starliner spacecraft.

The Starliner has experienced unforeseen problems that have postponed the astronauts’ return. Nasa now has a tight timeframe to address these issues before the Crew-9 mission’s arrival.

On June 5, 2024, Sunita Williams and Butch Wilmore embarked on their mission from Cape Canaveral Space Force Station in Florida, representing Boeing’s inaugural crewed flight under its commercial programme. This mission aimed to evaluate the Starliner’s performance, marking a crucial achievement for Boeing.

As the spacecraft neared the International Space Station (ISS), five out of its 28 thrusters unexpectedly failed. Furthermore, engineers detected five minor helium leaks in the service module of the Starliner, which hindered its ability to safely undock and return to Earth.

Uncertain timeline for astronauts’ return

Steve Stich, who oversees Nasa’s commercial crew programme, said the timeline for Sunita Williams and Wilmore’s return is still undecided. The spacecraft’s safe re-entry into Earth’s atmosphere is dependent on the proper functioning of its thrusters and helium systems, with any issues potentially endangering the astronauts’ safety.

Complicating the situation is the requirement to manage the docking ports on the ISS, as the Starliner needs to be undocked to make room for the Crew-9 mission.

Urgent docking port clearance needed

The Crew-9 mission, set to launch no earlier than August 18 will send Nasa astronauts Zena Cardman, Nick Hague, and Stephanie Wilson, along with Roscosmos cosmonaut Alexander Gorbunov, to the ISS aboard a SpaceX Dragon spacecraft. The need to vacate the docking port currently occupied by the Starliner is urgent to accommodate the incoming crew.

If the Starliner remains non-operational, Nasa might need to explore other options for returning Sunita Williams and Wilmore to Earth, possibly including the use of a SpaceX Dragon capsule.

While aboard the ISS, both astronauts have continued with their mission activities and have been updating Earth on their research and the Starliner’s status via space-to-ground communications.

On July 10, astronauts Sunita Williams and Butch Wilmore spoke with the media, offering details about their extended mission and the ongoing attempts to fix their spacecraft.

[With agency inputs]