Spacewalks and Repairs

Maintaining the ISS requires regular spacewalks (EVAs — Extravehicular Activities). Astronauts spend 6 to 8 hours outside the station in bulky spacesuits, performing repairs, replacing equipment, and installing new experiments. Each EVA needs hours of preparation, including breathing pure oxygen to avoid decompression sickness.

In 2018, crew found a small hole in a Soyuz spacecraft docked to the station, which was causing a slow air leak. They sealed it with epoxy, though the cause was never publicly settled. In total, over 260 spacewalks have been conducted from the ISS, the most active EVA site in space history.