JSC2012-E-238473 (21 Nov. 2012) --- European Space Agency astronaut Samantha Cristoforetti and NASA astronaut Terry Virts (partially obscured), both Expedition 42/43 flight engineers, attired in training versions of their Extravehicular Mobility Unit (EMU) spacesuits, are about to be submerged in the waters of the Neutral Buoyancy Laboratory (NBL) near NASA's Johnson Space Center. Divers are in the water to assist Cristoforetti and Virts in their rehearsal, which is intended to help prepare them for possible work on the exterior of the International Space Station. Photo credit: NASA