An anonymous NASA employee has customised a panel for the International Space Station, adorning it with an image of Space Core from Portal 2.
The part was blasted into orbit last Friday aboard a Japanese resupply craft.
It was photographed bearing an image of Space Core, along with his catchphrase: "In spaaaaaaace!".
"Please note that when we mentioned an 'anonymous tech at NASA' we weren't kidding: NASA in no way officially endorses secretly laser-engraving characters from Portal onto their spacecraft," a post on Valve's official Portal blog explained.
Space Core rode aboard the Japanese HTV-3 resupply mission, which lifted off on Friday at 17:06 UK time.
It's not the first time Portal 2's Space Core has snuck out of the Portal universe. The Nolan North-voiced robot previously was spotted crash-landing in Skyrim.