It’s been more than a year since scientists lost one of the most iconic telescopes ever built – and the demise of the famous Arecibo Observatory remains something of a mystery.
Nestled in the Puerto Rican jungle, Arecibo . ObservatoryIts crown jewel is the vast radio saucer, which spans 1,000 feet (305 meters) and is famous for appearing in films like James Bond’s “Contact” and “GoldenEye”. But six decades after the telescope came online, on December 1, 2020, the 900-ton scientific platform crashed through the fragile disc, abruptly ending the career of a equine telescope. child.
The collapse ended a multi-month streak of damage, but even a month before the collapse, the National Science Foundation (NSF), which owns the observatory but does not directly manage it, believes the engineers can still save the telescope. Now, a group of engineers are stepping in to understand what happened in Arecibo that makes its troubles serious. This analysis was released at the request of the NSF, in the hope of ensuring such a collapse never happens elsewhere.
Roger McCarthy, a mechanical engineer and chair of the committee led by the National Academy of Sciences, Engineering and Medicine that performed the analysis, told Space.com.
Whatever the committee discovers would be chilling comfort to the scientists who already work at Arecibo or use its data – and those are three distinct communities, as the tool has already done. does important work in radio astronomy, planetary radar observations, and atmospheric science.
Mike Nolan, a planetary scientist at the University of Arizona who was director of the Arecibo Observatory from 2008 to 2011, told Space.com: “Finding out what happened at Arecibo doesn’t really help them. , because Arecibo fell”.
And no other facility, NSF or otherwise, has designed anything like Arecibo’s giant racks and plates. But if all goes well, the investigation will identify factors that make the telescope so sophisticated that no one realizes how dire the situation is – factors that could be present at other facilities without NSF support.
Particularly in the field of astronomy, NSF facilities include major observatories such as the Atacama Large Millimeter / Submillimeter Array (ALMA) in Chile, the Gemini Observatory crosses the equator and the twins Gravitational Wave Observatory Laser Interferometer (LIGO) outposts in Washington and Louisiana. More are coming, like the Vera C. Rubin Observatory in Chile, which is scheduled to start observing next year.
“Each one of these, by their very nature, are cutting-edge scientific instruments that put an entirely new design to its test over a long period of time,” says McCarthy. “So the NSF wants to know, how should we monitor these? Because every structure in recession sends you messages.”
At Arecibo, those messages went unresolved.
Reviewing a disaster
Over the past decade, the Arecibo Observatory has faced challenges that include a string of earthquake and storms, most notably Hurricane Maria makes landfall in Puerto Rico in September 2017. At that time, NSF was evaluating proposals for a second change in operating institutions in a decade and a regulatory structure that would reduce the agency’s financial commitment to with observatory. The University of Central Florida took over the management of Arecibo, including the radio telescope and the rest of the site, in April 2018.
Just over two years later, one of the giant cables supporting the heavy scientific platform was unexpectedly above the giant saucer. slipped out of its socket and crashed through the telescope in August 2020. At the time, it was clearly involved, but it was not considered an emergency. But just as the engineers were about to stabilize the structure, another cable is broken in November, making NSF skeptical that the telescope could be saved.
The third cable broke on December 1, 2020, yielding the whole foundation collapsed and leaves behind three different scientific communities that have depended on the telescope for decades to come. More than a year later, no one is particularly pleased by the story put together so far, full of unsolved mysteries and untold warnings – hence the new analysis.
The committee’s first public meeting, held on January 24 and January 25, included presentations describing NSF’s overall activities in supporting and monitoring research facilities. , as well as recounting specific events that took place at the Arecibo Observatory both before and during the failure. .
McCarthy said he expects the committee to meet about five times in total. The next meeting, scheduled for next week, will include presentations from the engineers who analyzed the collapse. In March, the committee will personally visit the Arecibo Observatory to see what remains of the crashed telescope; The committee has eight months to compile its findings into a report.
In the story of Arecibo’s downfall, engineers have a series of clues they can use to piece together the full picture.
Among the evidence, there is a 600 pages NASA document inspected the defective outlet in August 2020. That report determined that the socket failed due to a phenomenon known as zinc creep, which the establishment’s consistent heavy loads could aggravate.
Engineers won’t latch the socket that’s the weak point; it’s only been around for about 25 years, while others have been at 60, and sockets aren’t considered a risk anyway. “This failure mode has never been identified before,” Nolan said. “The conventional wisdom is, the joint is stronger than the cable. And obviously, that’s not always the case.”
In addition to this investigative report, the lead engineers on the collapse are working on a similar report, to be conducted by the NSF next month, that includes forensic work on other components of the observatory.
Likewise, staff at NSF and the Arecibo Observatory, as well as the engineers involved in the site, spent much of the intervening months reviewing old paperwork, creating creating new models and analyzing the exact components of the observatory, all in the hope of finding out what was wrong.
Even as the whole story was still coming together, the clues painted a picture of a much less stable situation than anyone realized at the time, even before the break. cable first. Engineers know there is damage remaining from Hurricane Maria and a series of earthquakes that hit Puerto Rico beginning in late December 2019, but none of it is believed to need urgent attention.
“Many items have been tracked, so it’s not like it’s just one or two things – there’s a lot of concern,” said Ashley VanderLey, now senior adviser for facilities at NSF’s astronomy division, program manager for Arecibo in the fall, talking about the months before the August failure in the committee meeting. “And we all know that the weight of the platform is really close to the limit because no new tools are allowed to be added to the platform, so that has been a concern for a while.”
But tracing the concrete and steel can only tell one side of Arecibo’s story. The Commission should also be concerned with the processes that govern the NSF and its relationships with the organizations that administer their facilities, a task that the NSF is not authorized to perform directly.
First of all is the never-ending challenge of budget management. In particular, as NSF officials noted during the introductory committee meeting, their facilities often face strain over how much money is allocated for what is known as operation and maintenance, or BRAISED.
But while operations and maintenance are lumped together, they address different priorities in the short term. Operating money directly provides for observation and analysis – the heart of the science that NSF wants to fund, but maintenance money never really resulted in having to journal this year, even if This work is critical to the long-term future of the facility.
Unlike construction costs, operating and maintenance costs continue for decades, reducing NSF’s future budget. If the agency’s overall budget does not increase, the NSF also faces the need to prioritize funding between new and existing facilities.
“This is not a new problem, it is also an old NSF problem,” Linnea Avallone, director of the NSF research facility, noted during the meeting. “We always have to keep in mind that we’re building the next great thing,” she adds, “we’re collateralizing our future budget.”
The conflict between new and old facilities is why NSF seeks to step back from Arecibo as it proceeds with the design and construction of future observatories. But none of those projects have the ability and flexibility that Arecibo has, which continues to frustrate scientists watching the process.
“Most of the other facilities they’re talking about – telescopes and LIGO, accelerators and stuff – you decommission a facility because you built a new one,” Nolan said.
“Well, they’re not building a bigger, better new Arecibo,” he said. “We didn’t shut it down because we built the next greatest thing, we just decided not to do it anymore.”
https://www.space.com/arecibo-telescope-collapse-analysis-national-academies What happened at the Arecibo Observatory? New investigation is launched into the collapse of the iconic telescope.