This wasn’t the mailbox they were looking for.

As part of a celebration of the 30^th anniversary of the Star Wars saga, the U.S. Postal Service (USPS) turned 400 standard blue mailboxes into Luke Skywalker’s trusty droid, R2-D2. Star Wars fans tracked down these themed mailboxes on sidewalks and street corners across the country, documenting their progress in a vibrant Flickr community. But they couldn’t seem to track one R2-D2 down. As it turns out, this elusive mailbox was not sitting curbside, or even in a galaxy far, far away—it was part of the Smithsonian’s collection.

So how did such a distinctive postbox end up in the Smithsonian? In 2007, the USPS began a program of “skinning” postal boxes—or, applying themed, colorful pieces of vinyl to the sides of the metal mailboxes, turning them into sleek R2-D2s or, a few years later, a smiling SpongeBob SquarePants. To mark the anniversary of the opening of A New Hope in 1977, the USPS released a new set of Star Wars themed stamps and rolled out hundreds of R2-D2 post boxes.

Curators at the Smithsonian’s National Postal Museum took an interest in the campaign and reached out to the USPS, whom collections manager Elizabeth Heydt describes as having a close working relationship with the museum. The museum acquired stamps and one of the mailboxes for their collection. The mailbox, in particular, was a unique one—the USPS transferred its ceremonial mailbox, with a plaque bearing the signatures of George Lucas and Postmaster General John E. Potter.  

Another unique aspect of this mailbox, aside from its resemblance to R2-D2? It’s currently on display at a different Smithsonian museum – the National Air and Space Museum’s Steven F. Udvar-Hazy Center in Chantilly, Virginia.

Curators at both museums began discussing the possibility of the mailbox being loaned to the National Air and Space Museum from the National Postal Museum collection in 2007.

“Popular culture objects have a place at the Smithsonian’s National Air and Space Museum because the Museum has always been interested in how spaceflight has been imagined as well as how it has been realized,” National Air and Space Museum space history curator Margaret Weitekamp said. “Star Wars’ vision of space-borne adventures made an indelible impression in American culture and around the world.”

The R-2 mailbox offered a unique point of connection between both museums’ interest areas. However, as the Postal Museum’s loan coordinator Patricia Raynor notes, the museums’ collaborations began before the National Postal Museum even opened in 1993. Visitors to the National Postal Museum today will see some objects from the National Air and Space Museum’s collection on display, too, like the Wiseman-Cooke aircraft.

The R2-D2 mailbox went on display at the Udvar-Hazy Center in 2008, where it has remained since. This has posed its own set of challenges, however, that have brought the preservation teams of both museums together to work through solutions.

“The vinyl skins weren’t meant for longevity,” National Postal Museum preservation specialist Rebecca Kennedy said. The vinyl skins that outfitted the mailboxes were meant to be temporary—taken off and replaced, or removed all-together once the campaign was over.

“Vinyl is a form of plastic, and like most plastics we need to keep it in a very controlled environment,” Kennedy said. Things like light or heat could damage the plastic material, so the display conditions are monitored closely. Specialists from both museums are always on the lookout for early signs of plasticizing, like warping, that could indicate heat or environmental damage.

For teams across the National Postal Museum and the National Air and Space Museum, the experience of sharing R2-D2 with the public has been a special one.

“R2-D2 was my favorite Star Wars character,” Heydt said. Working with the mailbox “was one of those geeky moments that you got to see the behind-the scenes story of an object.”

For Kennedy and Raynor, it was a chance to see a whole new audience enjoying a piece of the National Postal Museum collection—with National Air and Space Museum visitors lingering near the display case, snapping photos of the museum’s own R2 unit.