NASA engineers still haven’t quite figured out what caused Luca Parmitano’s—an Italian astronaut aboard the ISS—helmet to fill up like a fishbowl, but they have a pretty good idea. In a short downlink video filmed on July 30, U.S. astronaut Chris Cassidy reveals the source of the water, and how it lead to what is probably one of the most terrifying situations imaginable. Space is frightening enough—but it becomes even more so when you’re faced with the real possibility of drowning miles above Earth.
According to Cassidy, Parmitano’s suit inexplicably began leaking cooling water into its ventilation system, and that water was then eventually dispersed into the helmet. Cassidy says NASA engineers still don’t know exact specifics—also frightening—but they’re investigating what caused the leak. What they do know, and what Parmitano hopes to never experience again, is that water filled the helmet during a spacewalk, scrambling his communication system. Worse, the water filled his ears, eyes, nose and mouth, causing the spacewalk to be cut short.
Parmitano actually recaps his side of the situation in a previous video, which you can see right here. In the meantime, check out Cassidy’s short explanation of what happened; it’s a traumatizing look at an event that almost turned deadly—in space. And now suddenly kids across the globe no longer want to be astronauts when they grow up.