Cosmonauts Encounter Toxic Coolant Leak During International Space Station Spacewalk

Cosmonauts Oleg Kononenko and Nikolai Chub faced contamination due to a toxic ammonia bubble during a spacewalk, marking the third coolant leak in Russian controlled segments within a year; the cause behind the repeated mechanisms failure is still under investigation.

Cosmonauts Oleg Kononenko and Nikolai Chub encountered a toxic ammonia bubble during a spacewalk at the International Space Station, marking the third coolant leak in Russian controlled segments within the last year.
The pair were inspecting a radiator on Russia’s Nauka laboratory when the toxic coolant bubble emerged, requiring them to immediately evacuate the area and subsequently clean their equipment to prevent contamination within the ISS.
Unexplained holes were found riddled through the radiator's panels during their inspection, with 'very even edges, like they've been drilled through', which has raised suspicion about the cause of the recurrent coolant leaks in the Russian segments.
Despite the unexpected coolant leak, Kononenko and Chub successfully added a synthetic radar communication system, and released a nanosatellite to test solar sail technology, although the latter's solar sail failed to deploy as far as the cameras could track.
While the main radiator on Russia’s Nauka module is operational, the leak resulted in the delay of two NASA spacewalks as engineers evaluated the data of the incident. Postponed spacewalks are expected to take place after implementing precautionary measures to reduce the risk of ammonia contamination within the ISS.