Why is using Coordinated Universal Time (UTC) critical for ISS operations involving multiple nations?

It eliminates ambiguity when coordinating input from centers like Houston and Moscow.

The adoption of UTC is fundamentally an administrative necessity for the ISS, which functions as a collaborative venture involving various countries such as the United States, Russia, Japan, Canada, and the European Space Agency. Using a single, globally recognized time reference prevents the inherent ambiguity that arises from constantly converting between different local time zones. For instance, coordinating a sensitive operation, such as maneuvering a robotic arm, requires simultaneous input from geographically distant mission control centers, and using UTC ensures that a specified time, like "14:00," refers to the exact same physical moment for every entity in the operational chain of command, thereby maintaining consistency for complex, real-time coordination.