Let's kick back and take it easy for the last Friday of the #summer, in the pool, with Apollo I astronauts. Here, they practice water egress procedures at Ellington Air Force Base in #Houston, Texas in preparation for NASA's first manned (crewed) spaceflight. Astronaut Edward H. White II rides life raft in the foreground. Astronaut Roger B. Chaffee sits in hatch of the boilerplate model of the spacecraft. Astronaut Virgil I. Grissom, third member of the crew, waits inside the spacecraft. Today, astronauts train for spacewalks at the Neutral Buoyancy Laboratory, or NBL, operated at NASA's Johnson Space Center (nasajohnson) in #Houston. It has underwater mockups International Space Station (ISS) modules, simulating the weightless environment of space. During early #Orion development, scale models of the spacecraft were tested at the facility to evaluate buoyancy and flotation characteristics of the spacecraft. As the agency progresses on its journey to Mars, the #NBL is being used to e...