How a Former Spy Satellite Could Help Solve the Universe’s Greatest Mysteries

Beneath the cathedral-high canopy of a tightly controlled NASA facility in Maryland, a massive space telescope rests on its side, a hulking mix of metallic gray and obsidian black. Its silver-coated mirror is hidden away, shrouded in a protective cover, and its solar panels, sequined with thousands of shiny sun-basking cells, are tucked in around its form, like petals of a flower anticipating the nighttime darkness.

A few dozen technicians maneuver around the structure, their voices echoing in the cavernous chamber. Some hoist themselves closer on construction lifts to inspect a sturdy white frame that surrounds the observatory. “Hazardous operations are commencing,” a lead technician says to the group, and soon the top of the room begins to hum with moving machinery.

On this June day at NASA’s Goddard Space Flight Center, the team is packing up the new Nancy Grace Roman Space Telescope before sending it off to the palm-tree-lined shores of Florida, where SpaceX’s powerful Falcon Heavy rocket will propel it skyward. A giant crane slides slowly across the ceiling, controlled from below by a technician with a joystick. The mechanism settles into position and then descends, an almighty claw in an arcade game, ready to pluck its $4.3 billion, 20,000-pound prize. “I’m always on edge for these kinds of things,” Tim Aland, a deputy observatory integration and test manager, says to me.

The Roman telescope is the latest of NASA’s grand astrophysics missions, scheduled to launch August 30. When it reaches its far-flung perch, a million miles from Earth, Roman will capture expansive views of the universe with an unprecedented combination of speed and sensitivity. The volume of data sent back home, according to Nicky Fox, NASA’s associate administrator for science missions, will be enough to fill “a hypothetical stack of science papers that would reach up to the moon.”

In its first five years, Roman will observe hundreds of millions of galaxies and the countless stars within them, as well as hundreds of millions of stars in our own Milky Way. These blazing data points, enormous and fascinating as individual observations, collectively will help scientists study the invisible components of the universe, dark matter and dark energy, which are two of the most enigmatic mysteries in science. These account for about 95 percent of the universe’s composition—and happen to be the keys to understanding its origins and how it may eventually end. Astronomers will also sort through starlight within our galaxy in search of alien worlds, adding tens of thousands of known planets to the existing catalog.

But today, Roman is inside the clean room, the largest of its kind in the world, designed to protect space-bound hardware from human contamination. I wear the same head-to-toe uniform as everyone else: face mask, hair cap, a jumpsuit of swishy white fabric, two layers of shoe covers, purple latex gloves duct-taped at the wrist, and a hood that resembles the rounded end of a marshmallow. No cell phones are allowed, but Roman managers agreed to let me bring mine, under the condition that I record only audio and set the device to airplane mode.

In this getup, only our eyes are visible, and they’re all trained on the crane mechanism as it hooks onto the frame around Roman. The goal is to lift the observatory and float it over to the bottom half of a transport container, which itself is like a miniature climate-controlled clean room. Workers have shifted Roman plenty of times during assembly and testing, but they’ve never done this particular sequence with the telescope.

“I get choked up every once in a while,” says Mark Melton, Roman’s chief engineer—who joined the project when Roman was just a PowerPoint presentation—while admiring it beneath the crane. In the shadow of the telescope, the technicians look like little aliens themselves, readying their latest heavenly creation. Zoom out even further, and they’re members of a fairly new spacefaring civilization, residing in one of the glittering spiral arms of their galaxy, anxious to explore the realm beyond their planet’s cloud tops.

The Roman telescope, with its primary mirror, an elegant, 7.9-foot-diameter glass disk, once lay abandoned in a warehouse in upstate New York, where no one was supposed to know about it. The telescope belonged to the National Reconnaissance Office, the agency that operates the United States’ spy satellites, and it was meant for a clandestine existence in orbit, its covert gaze perpetually turned down toward Earth. But the contractor in charge of the satellite imaging program reportedly blew through budgets and schedules so badly that officials canceled the whole effort in 2005. The leftovers sat around until 2011, when the spy office offered them to NASA free of charge.

At the time, the Hubble Space Telescope was still making discoveries after two decades in orbit, and technicians were working on the mirrors for the James Webb Space Telescope, which would launch in 2021. But scientists were already devising a concept for yet another observatory to join them. The space agency, not one to look a gift telescope in the mouth, accepted the spy hardware and began work on its reconfiguration.

“Most people were excited about it,” says John Grunsfeld, a physicist, retired astronaut, and former NASA official who oversaw the machine’s repurposing. Still, some were skeptical that the existing technology could be adapted for a completely different purpose, Grunsfeld says, including engineers who were looking forward to building hardware from scratch, making their own design choices rather than fiddling with a hand-me-down. “It wasn’t without its challenges,” he says. The spy mirror’s original coating was stripped away, and the glass was reshaped and finely polished to produce the desired prescription to scan the cosmos. The optics were then rigorously tested in the colder temperatures they would have to endure in operation as a telescope.

The mission is named after NASA’s first chief of astronomy, Nancy Grace Roman, also the first woman to hold a leadership role at the agency. Roman studied astronomy in the 1940s, earning a doctorate in the subject, despite the widespread gender discrimination of the time. “I was told from the beginning that women could not be scientists,” she would later say. In 1959, a NASA employee asked Roman, by then a researcher studying the properties of stars in the Milky Way, whether she knew anyone who might want to set up an astronomy program at the agency, which was only months old. She suggested herself for the job and held it for 20 years.

Roman, who died in 2018, championed Hubble’s creation; she organized a group of astronomers and engineers to dream up a telescope concept and then spent years lobbying congressional lawmakers for funding. Hubble has revealed a universe sparkling with galaxies, but the most distant ones lay beyond its observational range, hiding in infrared light the telescope could not record. And while Webb is capable of peering deep enough in infrared to find the earliest galaxies, it has a much narrower field of view. Roman will do something neither is designed for:  Its view will go gloriously wide, about a hundred times that of Hubble, and it can collect both visible and near-infrared light. Roman has a set of specs that scientists say are particularly suited to probe the story of the universe, from its perplexing beginning to its uncertain end.

Now 15 years in the making, Roman’s namesake telescope is nearly ready to vault into the void.

Cosmic shipping and handling is not a rushed process, and it requires a good bit of elbow grease. Before Roman makes any moves, the workers at Goddard must separate the observatory from its mount on the clean room floor by unscrewing the 192 bolts that connect the two. They start cranking away with oversize wrenches, and squeaks occasionally ring out in the chamber, like the staccato barking of a Pomeranian. Workers who come within a few feet of Roman pull a coiled cable from their uniform and clip it to a tether snaking around the observatory, diffusing the static electricity away from their bodies. “When you touch a doorknob in winter and you feel that shock—if you can feel that, you will have obliterated electronics on the spacecraft,” explains Missie Vess, a spacecraft systems engineer on the mission.

Melton, Vess, and I are on the clean room’s mezzanine now, overlooking the action. After several hours of methodical wrenching—truly, such work can’t be rushed—the team has hit a snag. As bolts were removed, the distribution of Roman’s weight shifted beneath the crane, tipping it ever so slightly. “It’s not quite level,” Melton explains, and now the final two pins are stuck. Their removal must be nearly seamless; brute force risks splintering hardware and contaminating the machinery.

So technicians start tugging on long cords dangling on either side of the telescope, tolling the mechanical bell of a pulley system. They pause after every round, checking Roman’s alignment. It’s a delightfully old-fashioned demonstration of physics know-how, a simple mechanical scenario that mathematicians solved many centuries ago. It’s not the type of physics that keeps theoretical astrophysicists up at night—the mysterious, elusive, existential questions that Roman may soon help them untangle.

Dark matter is all around us. At least, physicists believe it must be for their models of the universe to make any sense, despite having never observed the substance directly or knowing what it’s made of.

Astronomers first suspected dark matter’s existence in the 1930s, and became convinced of it after key observations in the 1970s; everywhere they looked, galaxies defied known rules about mass and gravity, remaining intact when they should have been drifting apart. The scientists determined that while this strange form of matter doesn’t reflect or emit any light, it has gravity, and it exerts that force to pull cosmic gas and dust together into stars, galaxies, and elaborate clusters of galaxies. Dark matter “caused all the structure in the universe around us,” says Dominic Benford, an astrophysicist and Roman’s program scientist. It then gave rise to “solar systems and planets and dogs and cats and all those other things,” he says.

There is much more dark matter in the universe than regular matter, scientists think, and they have since spent decades theorizing about what it could be, sketching out hypothetical dark matter particles and running complex experiments to catch them. The Roman mission is arriving at a fascinating moment in the discussion, says Priya Natarajan, a theoretical astrophysicist at Yale. “We still haven't found the particle, and we are nowhere near finding the particle,” Natarajan says. “The situation is really cloudy, but it’s cloudy in a way that it’s requiring us to step into something new.”

The leading candidates—heavy, slow-moving particles known as WIMPs (for weakly interacting massive particles)—are still in play, but in recent years scientists have begun seriously exploring other possibilities, such as axions, particles theorized to metamorphose into tiny units of light in extreme electromagnetic fields, and primordial black holes, which may have crumpled at the very beginning of the universe.

To help test such models, Roman will observe a phenomenon known as strong gravitational lensing, which occurs when the gravity of a galaxy in our sight line bends the path of starlight emanating from a galaxy right behind it, showing us distorted views of the farther object. Scientists can analyze the warped light for tiny distortions caused by clumps of dark matter, allowing them to work out the potential structure of the unseen material between the galaxies.

Roman is expected to reveal hundreds of instances of this galactic light-warping across cosmic time. “This is going to transform the field,” Natarajan says. Astronomers won’t stumble upon the dark matter particle itself, she says, but they’ll feel surer than ever before about the direction of their search.

Mustapha Ishak-Boushaki, a theoretical astrophysicist at the University of Texas at Dallas, expects a similar breakthrough in the study of dark energy, a phantom force with a powerful influence on the fate of the universe. More than a century ago, astronomers studying the glow from distant galaxies realized that those celestial systems were drifting away from us, and the farther they were from Earth, the faster they seemed to be moving. The astronomers concluded that the fabric of space itself was being stretched over time.

In 1998, researchers trying to measure this expansion discovered that it was accelerating, surprising the scientific community. “We thought that it would slow down, like when you take a ball and you throw it in the air,” Ishak-Boushaki says. “It’s going to go up, up, up; it slows down; it stops; and it comes back down because of gravity.” An unseen pressure was accelerating the ballooning of the cosmos instead and could eventually drive it toward a gloomy, empty existence.

The story took a dramatic turn just last year, when astronomers reported compelling evidence that dark energy, long thought to be a constant, immutable force, may actually be a dynamic phenomenon capable of evolving over time. Roman’s census of thousands of exploding stars, Ishak-Boushaki says, could help confirm this result, perhaps steering us toward a different cosmic destiny where the barreling expansion might cease, leaving a stable universe, or reverse course, crunching it all into a singular, soundless point.

And there may be still one more twist: Dark energy might not exist at all. What scientists think must be dark energy may be the effects of gravitational forces they haven’t yet discovered. To probe this possibility, scientists will use Roman’s wide-eyed observations of clusters upon clusters of galaxies to chart the cosmic scaffolding. “It could be that gravity at the largest scales in the universe is just different,” Ishak-Boushaki says.

At Goddard, the forces of nature eventually comply, releasing their grip on the final bolts, and suddenly Roman is airborne. Suspended by the crane, it moves with an almost supernatural stillness across the room, as if gliding on an invisible body of water, a sea of disembodied eyes following along. Melton and the other engineers around me, thrilled by the momentous spectacle —and perhaps loopy after nearly seven hours of standing and staring—break out into the famous escalating musical notes from 2001: A Space Odyssey, a melody heralding a great beginning.

The moment signals the start of more than one endeavor. Roman contains the seed of an idea for the next big astrophysics mission. In addition to its primary science instruments, the observatory carries a first-of-its-kind experimental system to photograph exoplanets—planets that orbit other stars—directly. The coronagraph, an intricate assortment of masks, prisms, and mirrors, works by suppressing the radiant shine of a star and catching the delicate light reflected by the planets in its orbit, a tremendous technical challenge from light-years away.

The instrument will target previously discovered worlds for practice. “The planets that we’re trying to image are a billion times fainter than their host stars,” says Jason Wang, an astronomer at Northwestern University who works on exoplanet imaging techniques. “Just a little bit of stray glare from the star could basically swamp out the signal of these planets.” 

Roman will still go searching for new worlds without deploying the coronagraph, and it’s expected to discover as many as 100,000 exoplanets between Earth and the galactic center using a quirk of gravity to spot the movement of planets around other stars. But Roman won’t resolve a true Earth twin: a rocky exoplanet our size, orbiting in the habitable zone of its home star. Neither will Hubble nor Webb. Such worlds are “like a firefly next to a searchlight,” says Grant Tremblay, an astrophysicist at the Harvard-Smithsonian Center for Astrophysics.

That’s why engineers are hoping to study Roman’s coronagraph performance to finalize designs for the next big telescope, the Habitable Worlds Observatory, which could launch in the 2040s. The mission would search for Earth-size planets around nearby sunlike stars, using our planet’s features as a guide to spot potential signs of life in their atmospheres. Capturing the light filtering through an alien atmosphere requires a telescope that can remain nearly motionless, without any wobbling that would make its observations blurry, Tremblay says. Telescopes experience vibrations from their humming internal systems, and even in space, they can jiggle, buffeted by the gentle breeze of the solar wind. “Some engineers think this is not solvable, and some people are really bullish,” Tremblay says. One possibility involves splitting the observatory in two in orbit, allowing the telescope to coast unencumbered during observations and then reconnect with the rest of the spacecraft.

NASA plans to evaluate the feasibility of mission designs by the end of the decade, when Roman will be beyond the orbit of the moon. The latest mission concept envisions an $11 billion project, departing in 2045, but otherworldly endeavors are subject to the whims of earthly circumstances, like budgets and politics. Roman itself was repeatedly marked for cancellation by the Trump administration, including as recently as last year, but Congress continued to allocate funding for the program. The current NASA administrator, Jared Isaacman, has said that he wants to accelerate the timeline for the Habitable Worlds Observatory, and has floated launching a series of smaller missions to build up to it. Fox, the NASA official, told reporters this spring that “we're not interested in doing something now that’s going to launch in the 2040s,” and says she would deny funding for a mission with that price tag. (Perhaps another free telescope might help—the National Reconnaissance Office actually gifted the space agency two leftover satellites, but “NASA does not currently have plans for the other donated asset,” says NASA spokesperson Claire Andreoli.)

Roman may not find an Earth look-alike, but as scientists wait for updates on Habitable Worlds, they can at least get to crossing off the universe’s other existential questions—and, perhaps, add a few more to the list. As with every major observatory launch, there’s a chance Roman will find something that no one thought to look for.

In the clean room, technicians secure Roman into its new configuration on the bottom of the transport container. They’ll leave the rest of the boxing-up operation for another day. “I’m sure they’re a little grumpy and hungry—it’s human,” Bear Witherspoon, the lead payload systems engineer, says. In the weeks after, they will usher Roman out of Goddard and onto a barge out of Baltimore and sail it down to Florida for launch preparations. For now, they peel off their special garments and step outside, into the familiar warmth of their own star.