Russian cosmonauts aboard the International Space Station (ISS) temporarily sealed off a segment of the station over the weekend after detecting an “unusual odor” originating from a visiting Russian cargo spacecraft, Progress 90. NASA confirmed the incident on Sunday, stating that the smell was likely caused by "outgassing" from materials inside the spacecraft.
What Happened?
The Progress 90 cargo capsule, which delivers scientific equipment, food, fuel, and other supplies to the ISS, docked on November 21 after launching from the Baikonur Cosmodrome in Kazakhstan. Shortly after its arrival, cosmonauts noticed an unfamiliar smell and observed “droplets,” prompting them to close the hatch connecting the Russian Poisk module to the rest of the ISS.
NASA later explained that "outgassing" was the probable cause. This phenomenon occurs when materials release gases upon exposure to space's harsh conditions, which include radiation and extreme temperatures ranging from 250°F (121°C) to -250°F (-158°C). The odor and droplets were unrelated to the Progress capsule’s toxic propellant — unsymmetric dimethylhydrazine and nitrogen tetroxide — according to Kelly O. Humphries, NASA's news chief at Johnson Space Center.
Air scrubbers were immediately activated, and NASA confirmed that the air quality aboard the ISS returned to normal levels. The odor dissipated quickly, allowing cosmonauts to resume transferring cargo from the Progress vehicle.
Reassurance for the Crew
NASA assured that there were “no concerns for the crew” following the incident. In a statement, Humphries noted that the odor was contained, and air quality in the station was monitored with contaminant sensors to ensure safety.
While the exact cause of the odor remains under investigation, NASA deferred to Roscosmos, the Russian space agency, for further details. However, Roscosmos has yet to comment.
A Continuing Saga on the ISS
This incident is the latest in a series of challenges involving Russian-controlled segments of the ISS. The Poisk module, where the odor was detected, connects to Zvezda, another Russian module that has experienced issues. Zvezda has been mostly closed off due to a persistent slow air leak. Cosmonauts only enter the module to retrieve cargo from visiting spacecraft.
Despite these issues, NASA emphasized that operations aboard the ISS, including cargo transfers, have continued without disruption. The ISS has been a symbol of international cooperation, hosting rotating crews of astronauts and cosmonauts from over 20 countries since 2000.
The Future of ISS Collaboration
The ISS is operated by NASA in partnership with Roscosmos, the Canadian Space Agency, the European Space Agency, and the Japan Aerospace Exploration Agency. NASA plans to maintain the station through 2030. However, Russian officials have not committed to extending their participation beyond 2028. A final decision on Roscosmos' involvement may not come until 2025, according to a recent report from NASA’s Office of the Inspector General.
Progress 90 and ISS Logistics
The Progress 90 cargo spacecraft plays a vital role in the ISS’s logistics, delivering nearly three tons of supplies during its latest mission. Its reliability highlights the interconnectedness of Russian and US operations on the station.
While the recent incident was brief and contained, it underscores the importance of maintaining stringent safety protocols in the unique and challenging environment of space.
The "unusual odor" from Progress 90 and the temporary lockdown of the Poisk module serve as a reminder of the complexities of life aboard the ISS. As NASA and its international partners plan for the station's future, maintaining safety and addressing ongoing technical challenges remain paramount to the success of this historic collaboration.