1,000 times faster than Hubble: Up close with the NASA space telescope meant to unlock the cosmos

GREENBELT, Md. — It's go time for NASA's next-generation space telescope.

After nearly two decades of development, $4.3 billion and the labor of hundreds of scientists and engineers, the Nancy Grace Roman Space Telescope is less than three months from launch.

From a point roughly 1 million miles from Earth, the telescope is expected to survey the cosmos, capturing panoramas of hundreds of millions of stars and billions of galaxies. With this observatory, NASA hopes to unravel the secrets of dark matter and dark energy and discover thousands of planets beyond our solar system.

That's because Roman will be able to survey and map more of the sky than ever before, at a pace hundreds of times faster.

Julie McEnery, the senior project scientist for the Roman telescope here at NASA's Goddard Space Flight Center, said that in just one month of data collection, Roman will be able to peer at underexplored parts of the Milky Way to study stars across a deep slice of the galaxy, building an astronomical catalog far larger than any that exists today.

"In the mission's first five years, it's expected to unveil more than 100,000 distant worlds, hundreds of millions of stars, and billions of galaxies," she said.

The Nancy Grace Roman Space Telescope, named after the woman who became NASA's first chief of astronomy in 1959, will join roughly a dozen space telescopes that the agency has in operation focused on a range of science targets.

NBC News got a rare, up-close look at the telescope during its final days in the clean room, where NASA has assembled it piece by piece over the past decade. By the end of this month, the bus-sized observatory will have been packed up, transported to Baltimore, then barged to the Kennedy Space Center in Florida ahead of a targeted launch on Aug. 30.

"It's like the kids are going off to college," McEngry said, her face pressed against a window overlooking the clean room to take in one of her final views of the telescope. "It feels almost emotional."

Read more: A behind-the-scenes look inside the restricted room where NASA built the Nancy Grace Roman Space Telescope

Seeing more of the sky than ever before, 1,000 times faster

The scope of what the Roman telescope will observe during its mission is difficult for the mind to grasp.

"If we were to take a single image that is produced from our main survey and try to fully display it with a set of 4K TVs, you'd need more than half a million TVs," McEnery said. "And just to give you a sense of the scale of that, if I was to lay out those 4K TVs, it would cover 45 city blocks. Or to pick something you actually look at, it would entirely cover El Capitan in Yosemite National Park."

That main survey will take more than a year to complete, during which time the telescope will gaze through the Milky Way's dense, star-packed center, known as the galactic bulge.

It's one of three primary surveys planned; another calls for the Roman telescope to scan about 12% of the entire sky in under a year and a half. The resulting map of the cosmos will allow astronomers to measure how fast the universe is expanding — which could shed light on two of the most puzzling phenomena in the universe: dark matter and dark energy.

Scientists think dark energy is accelerating the universe's expansion, while dark matter is thought to make up most of the matter in galaxies, but it's invisible and can only be inferred by the gravitational effects it exerts.

"We know that Roman will give us the definitive data to help us understand the twin mysteries of dark matter and dark energy," said Dominic Benford, the Roman telescope's program scientist at NASA headquarters in Washington, D.C.

The third survey will focus on supernova explosions that occurred up to 8 billion years ago. Peering back through this cosmic time machine will help astronomers trace how the universe has expanded over its history — offering further insight into dark energy.

The Roman telescope is often compared to the Hubble Space Telescope, which launched in 1990. The two are roughly the same size — about that of a semitrailer truck — and similarly barrel-shaped. But the new observatory should be able to survey the cosmos 1,000 times faster than Hubble, and each image will capture a patch of sky at least 100 times larger than one of Hubble's, according to McEnery.

"To put this into context, one month of Roman observations would correspond to a century with Hubble," she said.

An iconic panoramic view of the Andromeda Galaxy that Hubble captured, for instance, was a mosaic stitched together from more than 400 observations. Roman's large field of view would be able to capture the same panorama with only two, according to NASA.

Both Hubble and Roman perform what's known as spectroscopy: the splitting of light into different wavelengths or colors. Astronomers analyze these patterns, including which colors are emitted, absorbed or reflected, to gauge the size, temperature and composition of objects in space.

The telescope will sit at a location in space called L2, which is a Lagrange point, where the gravitational acceleration from the sun and Earth balance out. This allows the observatory to remain in a stable orbit. Just five such points exist, and Roman will share the same one as the James Webb Space Telescope, which launched in 2021.

Benford said that once it's up and running, Roman should work synergistically with Hubble and Webb.

"We might discover a new star-forming region in our own galaxy that has never been seen before, and then we can use the amazing set of tools on Hubble to study those interesting parts of space and learn about them in greater detail," he said. "We can do the same thing with Webb, but we need Roman to discover those objects of great interest."

Under budget and ahead of schedule

Benford has been involved in the Roman telescope project since the observatory was a pen-and-paper idea nearly two decades ago.

"It is a little hard to believe that after almost 20 years of working on this project, the moment when we ship the Nancy Grace Roman Space Telescope to Florida and send her out into space is almost upon us, and that I'm never going to get to see it again," he said.

The telescope didn't yet have a name when Benford got involved. The one chosen nods to a woman considered a pioneer of modern space-based astronomy. Nancy Grace Roman, who was born in 1925 and died in 2018, was nicknamed the "mother of the Hubble Space Telescope" in part because her colleagues credited her with winning congressional approval for Hubble. NASA's newest space telescope was named in her honor in 2020.

Unlike many other flagship NASA missions, the Roman telescope came in under budget and ahead of schedule — a feat that wasn't easy, Benford said.

"It has been a huge focus of my professional life to get this observatory into operation in space, and for many years it really felt like it was a constant struggle to do that," he said.

The project weathered major interruptions, including the Covid pandemic and the two longest government shutdowns in U.S. history (this year's and last year's). Originally, NASA had aimed to launch the Roman telescope no later than May 2027.

The observatory is slated to lift off atop a SpaceX Falcon Heavy rocket. After that, Benford said, the Roman telescope will journey for more than three months to its destination in space. Once it arrives, mission controllers will spend time testing the observatory's instruments before scientific observations can begin.

If all goes according to plan, Benford said the telescope's first images could be released by the end of this year.

"It could be around Christmas, so hopefully that's a nice present," he said.

NASA does not have another major space telescope in the pipeline. The agency has proposed a mission called the Habitable Worlds Observatory to search for signs of life on exoplanets, but even if that project moves forward, it would not launch until the 2040s.

As such, the Roman telescope's launch is particularly meaningful to Goddard's workforce, some of whom also worked on Hubble and Webb.

"Thrilled just seems insufficient — I've spent half my career on this," said Mark Melton, a mission systems engineer. He anticipates he will tear up when the telescope is finally deployed.

"It was paper. And now it's reality," he said.

This article was originally published on NBCNews.com