iss056e158493 (Aug. 27, 2018) — NASA astronaut Serena Auñón-Chancellor works to calibrate a Bone Densitometer aboard the International Space Station’s U.S. Destiny laboratory. The device measures the mass per unit volume (density) of minerals in bone using using Dual-Energy X-ray Absorptiometry (DEXA). It is being developed from commercial off-the-shelf hardware and is being designed to fit into an EXPRESS Rack locker. The Bone Densitometer takes quantitative measures of bone loss in mice, during orbital space flight, which are necessary for the development of countermeasures for human crew members, as well as for bone-loss syndromes on Earth, by commercial entities. Planned studies, both academic and commercial, require on-orbit analytical methods including bone densitometry.