Flight Engineer Christina Koch works in the Unity module

iss059e017072 (April 9, 2018) --- NASA astronaut and Expedition 59 Flight Engineer Christina Koch works on the Unity module's Maintenance Work Area where the Advanced Combustion via Microgravity Experiments (ACME) Chamber Insert was attached for hardware replacement. ACME is a set of five independent studies researching improved fuel efficiency and reduced pollutant production in practical combustion on Earth, as well as spacecraft fire prevention through innovative research focused on materials flammability.