Vera Rubin Engineering – IEEE Spectrum

The Vera C. Rubin Observatory, in Chile, saw its first photon a few months ago, a monumental event 25 years in the making. Senior Editor Evan Ackerman’s journey to Chile, to see the observatory and talk with the team about the multiple and massive engineering challenges they overcame, itself took more than a year to plan.

The visit was initiated by Italian photographer Enrico Sacchetti, who had arranged for exclusive access to the telescope. The story we wanted Ackerman to tell required more than a quick tour. So Sacchetti and Ackerman arranged to spend three nights on the summit of Cerro Pachón, sleeping during the day and then staying up late with the engineers and scientists as they worked to get Rubin “on sky.”

Ackerman and Sacchetti didn’t know exactly what would happen while they were there. In some ways, they got lucky—the few days before first photon were full of frantic activity. In other ways, they weren’t so fortunate. The dome covering the telescope wasn’t working, the moon (bane of astronomers everywhere) was near full, and Sacchetti came down with an illness that nearly required him to be evacuated down the mountain.

“Spotting a viscacha near the observatory is good luck for that night’s seeing.” —Evan Ackerman

“For a slightly panicked 24 hours, I enlisted the help of some amateur photographers among the Rubin staff to make sure that we had all the photos that we’d need,” Ackerman says. You can see some of their excellent work in “How the Rubin Observatory Will Reinvent Astronomy.” And Sacchetti recovered enough to get the crucial shots he wanted.

The same characteristics that make Cerro Pachón the perfect place for observatories can make it a challenging place to work. For Sacchetti and Ackerman, as well as the Rubin staff, schlepping up to the 2,600-meter summit from sea level took some adjustment. Ackerman didn’t have much of a physical reaction to the altitude. But he learned that mentally, the thin air hits everyone a little differently.

“I discovered a complete inability to remember schedules,” Ackerman recalls. “William O’Mullane, data-management project manager for Rubin, told me that for him, it’s feeling that he knows the answer to a question, but not what the answer actually is.”

In addition to scheduled interviews with engineers and astronomers, Ackerman wandered around the control room, joining conversations that seemed interesting. The Rubin staff isn’t superstitious, but he nonetheless heard some rumors involving the local fauna.

 Viscachas, which are a type of chinchilla the size of a rabbit, are a good omen for astronomers at the Rubin observatory.Evan Ackerman

“Spotting a viscacha near the observatory is good luck for that night’s seeing, as it should be. It looks like an aggressively cute cross between a squirrel and a rabbit, but it’s technically a kind of large chinchilla,” he says. Less cute are the Andean condors that live on the cliffs near the Southern Astrophysical Research Telescope, which is also located on Cerro Pachón. Seeing them in the air in the evening is a bad sign, Ackerman was told, which may be somewhat grounded in reality, since the thermals that the condors ride imply turbulent air around the mountain.

Even the other “unlucky” parts of the visit helped make the story better. The full moon, while overpowering much of the sky, lit up the outside of the observatory and resulted in some fantastic nighttime photos. And the temporarily nonfunctional dome led to several in-depth conversations about how difficult it is to get all of these bespoke systems to work with one another, and helped Ackerman appreciate the complex job of the commissioning engineers.