Techno :: How Do You Train Astronauts When You Don't Have Any Spaceships?

Dottie Metcalf-Lindenburger waves and smiles from inside her space suit as a bright yellow crane slowly lowers her into the world’s largest indoor pool. As the water closes over her head, a trio of divers swarm around her. They detach her 200-pound suit from its restraints and guide her down to a life-size replica of a portion of the International Space Station that hulks on the pool’s floor like a sunken galleon. The divers gently spin Metcalf-Lindenburger, 37, around and upside down as they fine-tune the flotation devices that render her neutrally buoyant—suspended underwater without rising or sinking, an approximation of zero gravity.

“Hearing me ok?” asks one of the technicians monitoring a video feed from the glass-walled control room overlooking the pool. “Yep, all set,” replies Metcalf-Lindenburger’s disembodied voice through the control room’s speakers. As she grabs a handrail on the faux space station’s exterior to begin her practice space walk, Led Zeppelin’s “Over the Hills and Far Away” starts playing on the shared audio connection. “Get-psyched music,” the tech tells me with a grin.

It’s just another day of astronaut school at Johnson Space Center, the 1,620-acre complex south of Houston that has served as NASA’s main training facility and launch center since the beginning of America’s space program. John Glenn prepared here to become the first American to orbit Earth. Neil Armstrong practiced the maneuvers that would take him to the moon. Now Metcalf-Lindenburger is joining the latest generation of the best-trained space travelers in the world. There is just one unresolved question: What exactly is this generation training for?