Short of finding you have an alien shapeshifter on board that's mimicking the face of one of your crewmates, there aren't many worse scenarios that an astronaut can experience on the International Space Station (ISS) than finding out you've sprung a leak. Or at least, so you'd think.
Yesterday, NASA announced that astronauts on the United States Orbital Segment (USOS) of the ISS will head over to the Russian Orbital Segment (ROS) while they try to locate a leak this weekend. NASA first noticed indications of a leak back in September 2019, but because of regular operations such as arrivals, spacewalks, and departures, it took time to gather enough data to confirm a leak above normal air loss rates.
The ISS is in fact always leaking very slightly, requiring repressurization by nitrogen tanks in order to keep the atmosphere pressure comfortable for the astronauts on board. That leak rate has increased slightly, making it necessary for NASA to locate and hopefully repair the source of the leak. To do this, the members of the Expedition 63 mission will head over and join the cosmonauts in the ROS. While they have their weekend away, NASA and its international partners will monitor the air pressure in each module.
There have been leaks before on the ISS, where the same safety procedures were followed. Back in 2018, NASA spotted a reduction in pressure on the space station while the astronauts slept. They eventually located a 2-millimeter-wide (0.08 inches) hole in the Soyuz hull. European Space Agency astronaut Alexander Gerst temporarily fixed the problem by jamming a finger in the hole like he was in a cartoon before the astronauts moved onto a more long-term solution; covering the hole in sticky tape (of the high-strength variety used in space, this isn't the kind of thing you'd use to wrap gifts).
At first, the leak was suspected to be caused by a micrometeoroid, before it was determined to be the result of a drill. What exactly caused the hole and at what stage of manufacturing is unclear, as Roscosmos has been tight-lipped about it. Dmitry Rogozin, head of the Russian space agency, told a youth science conference in 2019 "we know exactly what happened, but we won't tell you anything".
The new leak, while it might sound frightening, poses no threat to the crew or ISS, NASA said. It sounds dramatic, but the only real consequence will be that the astronauts have a sleepover in the Russian segment of the ISS.