Jan. 5—There’s nothing west of Socorro for dozens of miles but a valley framed by mountains and the San Agustin plains that seem to stretch forever into the distance. And then, soon after you pass tiny Magdalena, you can see it on the horizon, glinting in the sun and spreading over a massive tract of land.

It’s not just one gigantic antenna dish, but 28 of them, and depending on their aim, they can be spread over 22 miles or be pulled into a space less than a mile wide. It’s called the National Radio Astronomy Observatory’s Very Large Array, and with very good reason.

The massive edifice was built in the 1970s and tweaked to allow new technology in 2011; to this day, it’s the most powerful and most flexible instrument of its kind. More than 200 Ph.D.s have been awarded based on research conducted at the site.

And starting early this year, it’s getting a major facelift. The VLA, over time, will yield to the ngVLA, which stands for Next Generation Very Large Array, and construction on a prototype antenna dish will begin in January.

The construction of that dish — and subsequent troubleshooting — could take up all of 2024, and then, over the next dozen years, the National Radio Astronomy Observatory plans to build more than 200 next generation antenna dishes to bring the science into a new phase of evolution.

“It’s going to be a big project. We’re going to need a lot of people of all sorts of different skillsets,” says Patricia Henning, the NRAO’s assistant director for New Mexico operations and a former researcher, educator, and administrator at the University of New Mexico. “This is such an important part of the array that any changes to the design that need to happen, you want to find that out with the prototype before you make 200 of them.”

The old dishes, which weigh more than 200 tons each, will stay online for a while as the next generation is developed. The current construction estimate for the ngVLA is $2.3 billion, and it’s expected to cost $93 million per year in operational costs once it comes online.

DISH ON THE DISHES

The Very Large Array is open 362 days a year (closed on Thanksgiving, Christmas Day, and New Year’s Eve). The VLA, located about 50 miles west of Socorro, is open daily from 9 a.m. to 4 p.m., and visitors can take a self-guided tour that ends at the base of one of the giant antennas. Entrance to the site and visitor center costs $6. Visit public.nrao.edu/visit/very-large-array for information.

The tiny town of Magdalena, 24 miles west of the VLA, offers one of the state’s best areas for night-sky viewing and hosts star parties throughout the year. It’s also home to more than a dozen galleries and small history museums and sites that beckon exploration. More information at magdalena-nm.com.

Visitors to the site of the existing Very Large Array can see why it’s expensive to maintain. The massive dishes, each of which span 82 feet in diameter, stand on tracks that stretch for miles. Each one is serviced once every four months, so at least one is undergoing maintenance at all times.

The VLA site has its own machine shop, fire department, and gas station, and it takes a staff of 200 people to keep it humming at full efficiency. Rob Selina, a project engineer with the NRAO, says the next generation of dishes will require a staff three times as big to conduct all operations.

The original science mission will continue for a couple of decades, and then the NRAO will likely figure out how to renovate the site for an even longer life.

“These are generational endeavors in many respects,” Selina says of the ngVLA. “The VLA is a good example. It’s been operating for 50 years now, but it went through the EVLA upgrade in the early 2000s, where they basically ripped everything out of the antennas and re-did it. It went from being waveguide systems installed in the 1970s where individual RF signals were all piped down these long waveguide pipes back to a central building and combined — and that became fiber optic systems in the early 2000s.”

The interesting part of the science with the VLA, Selina says, is that it accomplished its original research goals from a very small percentage of its use. Over time, that allowed the scientists to re-evaluate what they were learning and to chart new ways of studying the universe.

More than 3,700 planets in 2,700 star systems have been confirmed since 1995, and the ngVLA may shed new light on how planets form. And with the existing VLA, Selina says, scientists were able to follow radio waves all the way back to the afterglow following the Big Bang.

“In that way, you can treat the universe as a laboratory,” he says. “If you want to understand how rocky planets like the Earth form, you can do local science on the Earth itself. But you can also look at other rocky planets in the universe, which is what a lot of the NASA exoplanet satellite survey instruments do. You can use a radio telescope and look at proto-planets — planets still forming around their star — and try to gain clues that way. Being able to look back in time, not just at things as they currently exist but at something as it existed 100 million years ago, or even a billion years ago, is really quite a powerful way of examining the universe.”

While the old dishes were great technology for their day, Selina says the new ones will take advantages from developments in composites and in computerized industrialization. They’re lighter, smaller, and less expensive to construct than the original Very Large Array antenna dishes. The new antenna dishes will also be easier to construct and maintain.

“These are all individual tubes that go to steel nodes,” Selina says of the antenna design. “They assemble kind of like a Meccano kit [a brand of model-building kits] where each individual tube is bolted into the node. You can do it all on site and everything has been machined to tolerance. It’s all correctly labeled with QR codes. You grab a piece, and you can identify it clearly; you bolt it up and it should be aligned. “

Another key design change is that the new dishes will not need to move on tracks. The VLA currently shifts its alignments in order to see cosmic phenomena a bit differently: When pulled together, they’re sensitive to large-scale structures, and when pushed apart to their furthest distances, they’re better at seeing detail. But they can’t see both aspects at once, so the dishes are reconfigured every four months.

That’s where the next generation will provide a marked improvement.

“If you’re looking at something big and old, it’s probably not moving too fast, and you can do that,” Selina says of the VLA. “Say you wanted to look at a proto-planetary system. You’re looking now at the dust around a star where a Jupiter-equivalent planet is clearing its orbit. You might not see the Jupiter-sized planet itself, but you’ll see the dust clouds that follow its Lagrange points, and you’ll see the arc it’s clearing. And that’s changing on Earth-scale time. That planet is orbiting its star; if I look at it now and look at it four months from now, it will be in a different position. So there’s a lot of value in getting all scales at once.”

One of the most interesting sticking points — and a topic the NRAO will freely share is still being debated — is when exactly the Very Large Array will be taken offline. The ngVLA is not expected to be fully operational until 2037, and it will ramp up as the VLA moves out of commission. At first, the prototype will make observations on the same cosmic phenomena the VLA is recording, and the data will be compared and cross-sectioned. As more next-generation antennae are built, the NRAO will make a decision on when to close the VLA.

It’s not an easy decision, and all interested stakeholders will be consulted.

“There are hundreds of people who use the VLA every year. Students need it for their work,” Henning says. “We don’t want to switch it off too soon, but there will be a transition period where we need to be building a new observatory. That’s complicated if you’re trying to run an observatory at 100 percent of its capacity and build a brand-new thing that is 10 times bigger.”

Henning, the former director of the Institute for Astrophysics at the University of New Mexico, says that science is rarely a straight line from question to answer but rather a series of discoveries that prompt questions you didn’t know to ask.

Less than 100 years ago, Karl Jansky ignited the field of radio astronomy by announcing the discovery of radio waves emanating from the Milky Way. The Very Large Array was named for Jansky, and Henning says that the ngVLA will be a natural extension of his work.

“He started the field. But that wasn’t his goal,” she says. “Scientists aren’t sitting around and saying, ‘Eureka!’ Engineers and scientists will be looking at something and say, ‘Well, that’s weird.’ That’s how discovery starts. It’s something you weren’t necessarily expecting or starting off to find.”