An Albert Einstein plush toy has taken a flight to the International Space Station, serving as the zero-gravity indicator aboard NASA's SpaceX Crew-5 flight on Wednesday.
For those unfamiliar with zero-gravity indicators, the job of figuring out when the ship has reached weightlessness is given to a small object such as a toy, bear, or other plushy. Not strapped down, it floats into the air and bobs around when that moment happens.
"A couple of years after he came up with his groundbreaking theory of special relativity, Albert Einstein, in his mind, still had a couple of loose ends to tie up," NASA astronaut Josh Cassada said shortly before the Einstein toy did its thing.
"While he was sitting in the patent office (because he wasn't famous yet) ... he had the happiest thought of his entire life. That thought was that a person in free fall could not feel their own weight. That thought, along with some others that he built upon, led to general relativity and our understanding of gravitation and the curvature of space-time."
"We are experiencing Einstein's happiest thought continuously, as the International Space Station has been doing for over 20 years."
Zero-gravity indicators go back to the first launch of humans into space in 1961, when cosmonaut Yuri Gagarin took a small doll and watched it float. NASA adopted the idea, and now take everything from sparkly stuffed dinosaurs to R2-D2 and Baby Yoda.