The ISS isn't huge inside. That means the crew lives in pretty close quarters while in orbit. The current crop of astronauts and cosmonauts cozied up to an extreme this week when all six of them squished themselves together into a single crew cabin.
NASA's Ricky Arnold tweeted a photo of the event on Monday, writing, "A new outer space record -- 6 people in a crew cabin the size of a phone booth!"
In case you're too young to remember what a phone booth looks like, it's a rectangular box designed to accommodate a single person making a landline telephone call in privacy.
A 1950s fad involved seeing how many people could fit into a phone booth. This was known as "phone booth stuffing." It was the planking of its time.
The ISS version features NASA astronauts Arnold, Serena Auñón-Chancellor and Drew Feustel; Roscosmos cosmonauts Oleg Artemyev and Sergey Prokopyev; and European Space Agency astronaut Alexander Gerst.
Feustel posted a video of the effort, which took some squeezing to pull off. "Phone booth trick ... not a lot of room to spare as we tried to see if the entire Expedition 56 crew could fit into the CDR's Crew Quarters on @Space_Station!" he wrote.
Artemyev posted his own video view of the proceedings, where you can hear the crew cracking up and cheering.