The European tradition of the “grand tour,” particularly active in the 18th century, saw young travelers, primarily male and usually wealthy, heading out across the continent along a well-worn circuit of historic sites. Their favored destinations included architectural wonders, such as the Pantheon in Rome and the Parthenon in Athens, and the tours often had a deliberate emphasis on the lost grandeur of antiquity.

Stopping off at abandoned abbeys and half-collapsed Roman aqueducts was part of the experience, as these picturesque lumps of masonry were seen as a moral reminder of what human effort could achieve—but also a sign of how easily civilization could collapse and be steadily erased by time.

The grand tour of the future, however, according to historian of astronomy Randall C. Brooks and conservationist Robert Barclay, might take place off the Earth entirely, involving a tour of derelict satellites and abandoned spacecraft, those ruined cathedrals of the sky.

In a paper called “In Situ Preservation of Historic Spacecraft,” collected in the massive 2009 Handbook of Space Engineering, Archaeology, and Heritage, they specifically use the analogy of the grand tour to describe this vision of future tourists planning “visits to preserved space vehicles.”

“In the eighteenth century it was the fashion to take the grand tour and to visit the sites of ancient Egypt, Greece, and Rome,” they write. “In the nineteenth century the museums, galleries, and historic sites of the world burgeoned under new waves of historic cultural awareness.”

“In the twenty-first century,” however, “we can be sure that people will be visiting heritage sites beyond the confines of our atmosphere.” Indeed, as the title of their paper suggests, these abandoned satellites and other spacecraft will likely be preserved in situ, still actively orbiting the planet or even circling a Jovian moon, but certainly not displayed behind glass somewhere in an earthbound museum.

In this vision of what Barclay and Brooks describe as “the future of museums beyond the atmosphere,” tomorrow’s grand tourists will come face-to-hull with ancient spacecraft, the way economically privileged Europeans once visited Notre Dame or the Colosseum. Their new destinations will be archaeological sites in space.

Alice Gorman is a professor of archaeology at Flinders University, where she is also deputy chair of the Space Industry Association of Australia. For Gorman, performing archaeology outside of a terrestrial context means that “we have to rethink the meaning of place” altogether. This is both difficult and essential. After all, she explains, “a prerequisite for gathering archaeological data is knowing where things are”—yet the very idea of a fixed location falls apart when the object of study is in constant motion. “In orbit,” Gorman writes, “position changes every second and must be continually tracked in order to know where to locate an object.”

For an archaeologist studying satellites this is uniquely troubling, and it means that it can be next to impossible to define an actual historic “site.” At best, you can supply an equation for a particular satellite’s intended orbit and then wait for it to reappear there, like the so-called Iridium flare; but, even with geosynchronous spacecraft, you’re often dealing with an unclear smudge of locational probabilities. It’s like excavating the walls of Troy, only to come back the next day and find that the city has somehow moved.

If archaeologists want to maintain a record of what is in orbit, and to keep tabs on those objects in the future, then something beyond mere maps will be necessary. For Gorman, this means reconceptualizing archaeological space itself, as something that is topological rather than geographic.

Gorman has thus advocated thinking about offworld historical research—the in situ study of abandoned satellites and derelict spacecraft—in terms of how those objects interact with the planet’s gravity well. It is about trajectory, we might say, not location. As Gorman explained to me, this could have far-reaching conceptual implications for how archaeologists define and study offworld artifacts.

Even more than this, however, she pointed out that traditional archaeological methods such as stratigraphy—whereby archaeologists note which objects are lowest, and thus oldest, in a particular dig site—have no real value in space. Instead, she suggests, archaeologists will have to go back to an earlier phase of their own profession, before stratigraphy was accepted as a general rule.

Because a satellite orbiting higher than another satellite is not guaranteed to be newer than the satellite below it, you instead need to look for things such as style and type. This means, with no small irony, that space archaeologists will have to act more like 19th-century connoisseurs or art historians, searching for visual similarities amongst diverse families of objects and then establishing relations based on physical resemblance, in order to reconstruct the history of a given spacecraft. The shape and size of a satellite will matter far more than its altitude—think of the spherical body of Sputnik, from the 1950s, compared to the tiny “CubeSats” of today—as well as the materials used to construct it.

Of course, the idea of pursuing archaeology in space is by no means unique to Gorman. Robert Barclay, Randall C. Brooks, P. J. Capelotti, Ann Garrison Darrin, and, in particular, Beth O’Leary at the University of New Mexico are just a few of the other people dedicated today to exploring humankind’s offworld archaeology. If, as artist Trevor Paglen has pointed out, geosynchronous satellites will far-outlast all other human constructions, from the Pyramids to today’s megacities, then archaeologists are right to wonder how these astral objects will be understood by future generations.

It’s worth mentioning at least one other approach to these offworld historic artifacts. Resurrecting dead satellites, rather than merely studying them, is another way to perform what aerospace entrepreneur Dennis Wingo has called “techno-archaeology.” In the summer of 2014, Wingo and a pirate flag-flying crew of computer science colleagues led an unlikely but ultimately successful attempt to contact an abandoned satellite—the International Sun-Earth Explorer-3, or ISEE-3.

Wingo’s team operated out of a pop-up deep-space communications lab, constructed in a defunct McDonald’s near NASA’s Ames Research Park south of San Francisco. Communicating with the satellite required reconstructing, on the fly, the craft’s archaic programming language while simultaneously reverse-engineering its long-lost operating manual. It was more like cracking the Rosetta Stone than it was a contemporary space operation, a kind of celestial Egyptology.

One key to their success was that the satellite “was never turned off,” The New York Times reported at the time, “so while Earth lost its ability to talk to it, ISEE-3 was still broadcasting, waiting for its next command.” And that command finally came through, beamed up from this repurposed McDonald’s in California.

Waking up an apparently dormant satellite is a useful example for discussing one final aspect of Alice Gorman’s work. Gorman’s nickname, Dr. Spacejunk, is a humorous reference to the dismissive attitude many people have toward objects in space. Rather than seen as wonders of human engineering, on par with the great archaeological sites of Europe, these obsolete satellites are mere “spacejunk.”

However, Gorman pointed out to me, the difference between a functioning spacecraft and derelict spacejunk can be a matter of days or even minutes. As she put it, “the distinction between what’s junk and what’s not junk” is far from rigorous, which also means that archaeologists should be prepared to study both.

Of course, this is usually seen from the point of view of impending obsolescence, of a craft going dark after decades of service or a new satellite failing to perform upon reaching its intended orbit.

But, as Wingo’s efforts show, sometimes this can work the other way, with spacejunk once again becoming functional—as if the sky above us is filled with sleeping machines that have tricked us into thinking like archaeologists when, in fact, they’re simply waiting for the right command to turn back on. They are ruins in the sky, on the verge of a new purpose.