In the photo above, the Mercury Seven astronauts stand together in white one-piece outfits, their heads wrapped with more white cloth. They’re straight-faced and dirty, looking like a rogue gang from Mad Max. You can own this picture, taken at the astronauts’ “survival school,” for somewhere around $1,500 if you bid on it at Bonhams' Space History Auction.

At the auction, which begins at 1 pm Eastern on July 20, space collectors will vie for memorabilia that ranges from the space race’s earliest years to the space shuttle program. The pieces for sale have a mix of origins: “deaccessioned” items from anonymous institutions, private collectors, even astronauts themselves. And the people who bid on concrete bits of space nostalgia are themselves a mix. Some love old photos best; some feel partial to autographs; others like to own instruments that have made their way out of Earth’s atmosphere. Then there are the people who have spacesuits hanging in their houses. But they all have one thing in common: They heart space.

Bonhams

“Anybody can get excited about it,” says Cassandra Hatton, who heads up the space history sale. “You don’t have to have a background in science to get excited about going to the Moon. That’s different from other areas, like old master paintings.”

Of course, not everyone has the means to bid on Bonhams’ particular pieces of history. There’s a full-scale model of Sputnik-1 ($10,000-$15,000), Yuri Gagarin’s flight map ($800-$1,200), and the actual spacesuit that astronaut Don Pettit wore on his return from International Space Station Expedition 6 ($25,000-$35,000). Or maybe you’re interested in the hand casts that engineers used as molds for spacesuit gloves ($6,000-$9,000). In their glamour shot on the auction website, the set of gilded, disembodied hands reach in creepy unison toward the sky .

The Sputnik model is one of Cassandra Hatton’s favorites. “There are very, very few of those,” says Hatton. This one in particular scientists used for electromagnetic interference testing before the real Sputnik launched. “It still works,” says Hatton. “It makes me want to move into a loft so I can buy it and hang it from my ceiling.”

Luckily for the loftless, Bonhams isn’t the only place to find a piece of space. Space is the great equalizer—and that applies to the collection world, too.

The Egg Crate

Robert Pearlman—the founder of the website collectSpace, the central gathering spot for celestial collectors—is too young to have witnessed the Moon landing. But his mother did save newspaper clippings from the event, and he was always interested in space, always wanted to be an astronaut. He went to Space Camp six times.

And then one day in high school, Pearlman read an article about a Florida man who scooped up space memorabilia. “I didn’t know that was a thing,” Pearlman says. “I grew up in New Jersey. There wasn’t a lot of space in New Jersey.”

He wrote to the Florida man, asking him how a person became a person who owned such treasures. “Four weeks later, a box arrived in the mail, filled with space memorabilia,” says Pearlman.

The items were for Pearlman to keep, the man wrote in a note. While he loved all of it, his favorites were the small pieces that had actually gone to space. “I could imagine myself going along with them,” he says.

He was hooked. By the time he finished with school at the University of Maryland, College Park, his collection overflowed an egg crate.

Pearlman accidentally founded collectSPACE because he was moving and wanted to document his own collection—it was early Internet days, before Google. But another collector wrote to him, saying he’d found the site and knew of other space collectors who would be interested in being part.

Bonhams

The site went live on July 20, 1999. Pearlman set up a message board that November, and around 100 people were chattering away by the end of the month. Today, collectSPACE has 50,000 registered users, all interested in space history and the gathering-up of it.

“Space memorabilia is a way to save the nuts and bolts of the programs,” says Pearlman, the pieces that don’t necessarily belong in museums—often because their explanatory placards would be too long—but are historically valuable nonetheless. Now, collectSPACE links to lots of individuals’ collections.

But who are these collectors? Are they the same as the Bonhams bidders? “The hobby attracts all different types of people,” says Pearlman. “But there are demographic pockets that are larger than others. The hobby does seem to attract people in their 40s-60s, and now their 70s.” Those who witnessed the lunar landing, he says, and more men than women, although the community does have a lot of women. Regardless of gender, collectors tend to have money because, well, pictures of the Mad Max Mercury Seven aren’t cheap.

Still, Pearlman says, it doesn’t have to be an expensive hobby. “You don’t need to be able to afford anything more than a stamp,” he says, to send NASA a request for an astronaut autograph. “Bonhams represents a very specific audience. Their bid amounts and their valuations are high—not unheard of and not unwarranted for what they’re auctioning. But for under $100, you could build a very respectable collection.”

So while Bonhams might not be the place to start, the actual start-up cost can be low. And those who don’t want to bid on a model of the first Soviet spy satellite on Wednesday may prefer to think of the space auction offerings, which each have their own webpage, as a fun and educational picture book, where you can look at and learn about—if not touch—a little piece that went to heaven.