Expedition 56 Chancellor of NASA is pictured in the Destiny laboratory module with gear from the Marrow investigation.

Expedition 56 Flight Engineer Serena Auñón-Chancellor of NASA is pictured in the Destiny laboratory module with gear from the Marrow investigation. She was collecting breath samples to analyze and measure red blood cell function to help doctors understand how blood cell production is altered in microgravity. Results may improve the health of astronauts on long-term missions and help patients on Earth with mobility and aging issues.