During last week's spacewalk aboard the ISS, astronaut Luca Parmitano suffered a slight—but terrifying—wardrobe malfunction: his helmet began filling with water. Today, astronaut Chris Cassidy shows us the suit in question and guides us through exactly how it failed.

According to Cassidy, roughly a half liter of water had leaked into his ventilation system, covering his mouth and nose, and forcing the crew to abort the walk. NASA's boffins have already delivered an emergency repair kit aboard a Russian Progress autoshuttle and are still investigating the root cause of the mishap.