Astronauts had to return to the ISS just one and a half hours into a spacewalk today after water began leaking into the helmet of European Space Agency astronaut Luca Parmitano. PopMech contributor and former astronaut Tom Jones reports.

Astronauts train for their spacewalks at the International Space Station while submerged in Houston in a six-million-gallon water tank, learning to better understand and cope with the free-fall environment of orbital flight. But they expect to leave all that water behind after launch.

Today at the ISS, however, an unusual and serious water leak threatened to engulf European Space Agency astronaut Luca Parmitano, nearly blinding him inside his helmet and forcing NASA to cut short their maintenance spacewalk after just 1 hour and 32 minutes. Parmitano made it back inside the station safely, and Tuesday afternoon NASA officials told the media they were still investigating how this water leak could have happened.