McArthur and Tokarev suiting up for Expedition 12 NBL Training Session.

JSC2005-E-18896 (12 May 2005) --- Astronaut William S. McArthur, Jr., Expedition 12 commander and NASA Space Station science officer; and cosmonaut Valery I. Tokarev (obscured), Station flight engineer representing Russia's Federal Space Agency, are submerged in the waters of the Neutral Buoyancy Laboratory (NBL) at Johnson Space Center (JSC). McArthur and Tokarev are wearing training versions of the Extravehicular Mobility Unit (EMU) space suit. SCUBA-equipped divers are in the water to assist the crewmembers in their rehearsal, intended to help prepare them for work on the exterior of the International Space Station.