On November 23, the crew aboard the International Space Station (ISS) reported an unusual smell while opening the hatch to the recently docked Russian Progress MS-29 cargo spacecraft, leading to the immediate implementation of decontamination procedures according to a tweet posted by International Space Station on the platform X. The spacecraft, which had docked successfully to the station’s Poisk module, was found to contain an unexpected odour and visible small droplets, prompting the crew to close off the affected area as a safety measure.

As reported by multiple sources, the source of the odour, described by NASA astronaut Don Pettit as “reminiscent of spray paint,” raised initial concerns regarding potential contamination within the Russian segment of the ISS.

While Pettit’s description highlighted the intensity of the smell, NASA and Roscosmos both activated air-purification systems to address the potential risk. The American segment deployed its Trace Contaminant Control Subassembly (TCCS), while additional filtration systems were engaged in the Russian module to restore air quality. As a further precaution, all crew members donned personal protective equipment (PPE), the official handle of ISS clarified in a post.

Continuous Monitoring Ensures Crew Safety

With air sensors monitoring the environment continuously, flight controllers confirmed by November 24 that the station’s air quality had returned to safe levels. This update allowed the crew to reopen the hatch between the Poisk and Progress modules without any risk. Though the specific source of the odour remains under investigation, officials have indicated that there are no current safety concerns for the crew, and the air quality is back to normal levels according to several reports.

Routine Resupply Mission Unaffected

Progress MS-29, part of a standard resupply mission, launched from Baikonur Cosmodrome on November 21, bringing essential items such as food and fuel to the ISS. The spacecraft will remain docked for the next six months before transporting waste materials back to Earth. Despite the initial alert, ISS operations have been confirmed to continue as planned, with safety protocols ensuring no interruption to station activities.

Sources at NASA and Roscosmos have assured that efforts are underway to identify the origin of the odour and further preventive measures will be implemented as required.