An ‘unexpected odor’ was reported at the space station

Operators of the International Space Station (ISS) were recently alerted to what was described as an “unexpected odor” emanating the Russian Progress cargo spacecraft that docked with the orbital outpost on Saturday.

After launching from the Baikonur Cosmodrome in Kazakhstan, the Progress spacecraft brought with it about 2.5 tons of supplies and other cargo for the seven-person crew aboard the orbital outpost. The spacecraft’s arrival at the station’s Poisk module appeared to go smoothly, but when Russian cosmonauts Ivan Vagner and Aleksandr Gorbunov opened the spacecraft’s hatch, they noticed an odor along with drops of an unidentified liquid.

Out of an abundance of caution, the cosmonauts left the area and closed the Poisk hatch to the rest of the Russian segment. Space station air scrubbers and contaminant sensors then monitored the station’s atmosphere, and on Sunday, flight controllers were able to confirm that the air quality inside the ISS was at normal levels.

“There are no concerns for the crew, and as of Sunday afternoon, the crew is working to open the hatch between Poisk and Progress while all other space station operations are proceeding as planned,” NASA said in a post on X.

In an update posted on its website on Monday, NASA said that Roscosmos cosmonauts have since reported that the odor quickly disappeared, and that it may have been caused by “outgassing from materials inside the cargo spacecraft,” though it failed to mention anything about the droplets. Cargo transfer from the Progress capsule to the main station are now proceeding on schedule.

It’s not the first time that a Russian spacecraft docked at the ISS has been at the center of attention. A more serious event involved a dramatic coolant leak on a Soyuz spacecraft in December 2022. After investigating the issue, it was determined that the damaged craft might not be safe enough to bring home the three crew members who arrived in it, so Russia sent up a replacement. And in 2021, Russia’s docked Nauka module caused a scare when its thrusters suddenly fired up, temporarily pushing the ISS out of orientation. No one aboard the station was injured in the incident and the facility was soon returned to its correct orientation.