Sunita Williams-led team encounters toxic smell at ISS, here's how the astronauts responded

A “toxic” smell detected on the International Space Station (ISS) by Russian cosmonauts led to emergency measures by the astronauts aboard led by Commander Sunita Williams. The incident was reported while opening the Progress MS-29 cargo spacecraft.

The strange odour was detected shortly after the docking of the spacecraft at the Poisk Module of the ISS. When the hatch was opened, cosmonauts noticed an unusual smell and small droplets, raising alarm for the astronauts onboard. The crew resorted to prompt actions: immediately closing the hatch and isolating the affected area.

Also read | Next stop for Curiosity rover? 'Spiderwebs' on Martian mountain

Air-scrubbing systems were activated by NASA and Roscosmos to purify the atmosphere inside the space station. While the US segment deployed the Trace Contaminant Control Subassembly (TCCS), additional purification technologies were used by the Russian segment.

The atmosphere inside the ISS returned to normal by November 24. The NASA flight controllers confirmed, “There are no safety concerns for the crew, and all operations are proceeding as planned.”

While the issue was resolved, it is unclear whether the toxic smell came from the Progress spacecraft or the vestibule that connects it to the ISS. The investigation is going on, exploring both possibilities.

Also read | What is inside the moon’s inner core? Here’s what scientists revealed

The Progress MS-29 spacecraft was carrying supplies, including food and fuel, to the ISS. Launched on November 21 from the Baikonur Cosmodrome, it is scheduled to return to Earth after six months with the waste materials.

NASA astronauts Sunita Williams and Butch Wilmore have been stranded on the space station since June this year due to the technical difficulties they faced with Boeing’s Starliner spacecraft. Their rescue mission is expected to be scheduled in February 2025 via a SpaceX Dragon ship.

(With inputs from agencies)