Expedition 56 Flight Engineer Ricky Arnold of NASA (foreground) performs maintenance inside the Combustion Integrated Rack.
iss056e021157 (June 19, 2018) — Expedition 56 Flight Engineer Ricky Arnold of NASA (foreground) performs maintenance inside the Combustion Integrated Rack to set up the Advanced Combustion via Microgravity Experiments (ACME), a series of five independent studies of gaseous flames. Expedition 56 Commander Drew Feustel of NASA is seen in the background.