In the International Space Station's Columbus laboratory, NASA astronaut Chris Cassidy, Expedition 36 flight engineer, performs an ultrasound on European Space Agency astronaut Luca Parmitano, flight engineer, for the Spinal Ultrasound investigation. Medical researchers have observed that crew members grow up to three percent taller during their long duration missions aboard the station and return to their normal height when back on Earth. The Spinal Ultrasound investigation seeks to understand the mechanism and impact of this change while advancing medical imaging technology by testing a smaller and more-portable ultrasound device aboard the station.