As reported earlier today by astronauts on the International Space Station, “small white flakes” were observed floating away from the station and into near space. It turns out that those white flakes are ammonia, and the levels that are being expelled are increasing. Not good, but the crew is in no danger, thankfully.
In order to understand how this happens, it takes some background knowledge: the ISS uses chilled liquid ammonia to cool the space station’s power channels on its large eight solar array panels, while each array has its own independent cooling loop. It’s being taken very seriously, as mentioned by NASA to SPACE:
If they lose the ability to cool that particular solar array, it won’t be able to generate power for the station. In fact, the leak has worsened to the point that Mission Control expects that particular loop to shut down within the next 24 hours.
In order to combat this error, NASA plans to reroute power on the station to isolate the issue.