NASA has raised the alarm over a “toxic smell” and “possible contamination hazard in the form of droplets” emanating from a Russian spacecraft that has docked at the International Space Station (ISS).
The uncrewed Roscosmos ISS Progress 90 is filled with nearly three tons of supplies and cargo.
It docked at the Poisk module section of the ISS on November 23 and was scheduled to remain attached for six months.
However, astronauts onboard the ISS identified a smell immediately after opening the hatch.
A Russian crew donned protective gear and activated an extra air-scrubbing system in the Russian segment of the ISS for about 30 minutes.
Meanwhile, NASA astronaut Don Pettit noted a “spray paint-like” odour in the Node 3 module on the US section – although its connection to Progress 90 remains unclear.
In a statement, NASA said: “Space station air scrubbers and contaminant sensors monitored the station’s atmosphere following the observation.
“By Sunday, flight controllers confirmed the air quality inside the ISS had returned to normal levels.”
The space agency emphasised that there were no immediate safety concerns for the crew. However, the hatch between the Poisk module and the cargo ship remains closed.
Russian media has also reported the “toxic smell”. NASA said cosmonauts noticed an unexpected odour and small droplets, leading to the decision to seal the Poisk hatch.
The incident has added to concerns about the ISS’s structural integrity. Earlier reports revealed that NASA and Roscosmos are monitoring over 50 “areas of concern” – including an air leak in the Russian Zvezda Service Module Transfer Tunnel, reported the Mail Online.
The Zvezda Service Module, installed in 2000, has experienced air leakage since 2019. Despite efforts to seal the cracks with patches and sealant, the problem has continued.
In April, the leak reached a record rate, with the station losing 3.7 lbs (1.68 kg) of air daily, prompting NASA to escalate the issue to the highest threat level. NASA officials have been negotiating with Roscosmos to keep the hatch sealed except when necessary.
NASA associate administrator Jim Free told The Washington Post: “We have conveyed the seriousness of the leaks multiple times, including when I was in Russia earlier this year. We’ve come to a compromise that they close it in the evening.”
A report from NASA’s Office of the Inspector General (OIG) in September confirmed the leak poses no immediate threat to the station’s structural integrity or crew safety.
ISS program manager Joel Montalbano reiterated that the issue does not currently impact operations but remains an area of concern.