Expedition 64 Flight Engineer Michael Hopkins is pictured during operations with a science freezer that preserves biological samples at ultra-cold temperatures.
iss064e007106 (Nov. 30, 2020) — NASA astronaut and Expedition 64 Flight Engineer Michael Hopkins is pictured during operations with a science freezer that preserves biological samples at ultra-cold temperatures. Known as Minus Eighty-Degree Laboratory Freezer for ISS (MELFI), it preserves a variety of life science samples such as blood, saliva, microbes and plants for later analysis.