European Space Agency astronaut Luca Parmitano reported "a lot of water" inside his helmet during his excursion outside the International Space Station (ISS) Tuesday. Because of the potentially dangerous situation, mission controllers on the ground decided to abort the spacewalk.
NASA astronaut Chris Cassidy and Parmitano returned safely to the U.S. Quest airlock, and engineers began trying to figure out what caused the mysterious and unprecedented leak -
"Clearly we have a problem at this point that we don't quite understand," Kenneth Todd, the ISS mission management team chair, told reporters Tuesday.
NASA officials have already made some progress in narrowing down the source of the leak. Initially, Parmitano and Cassidy thought that the astronaut's drinking water may have been leaking into the suit. However, the spacewalk team says that the cooling system in Parmitano's suit is a more likely candidate.