Expedition 56 Flight Engineer Serena Auñón-Chancellor of NASA is pictured in the Unity module during life support maintenance work to remove and replace an Oxygen Generation System Hydrogen Sensor.
iss056e014502 (June 18, 2018) — Expedition 56 Flight Engineer Serena Auñón-Chancellor of NASA is pictured in the Unity module during life support maintenance work to remove and replace an Oxygen Generation System Hydrogen Sensor.