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Nobody expected the snap of November 6 as engineers at the Arecibo Observatory in Puerto Rico they evaluated options for addressing damage to the facility caused by a cable failure during the summer.
But just as the engineers were ready to begin repairs on that secondary cable, it slipped out of its grasp in August, faced a much more serious challenge: one of the main cables broke unexpectedly, putting the entire structure at risk.
“We’ve seen a few single wire breaks on that particular cable, but we haven’t seen any changes for weeks,” Francisco Cordova, the observatory’s director, told Space.com.
Related: The Arecibo Observatory: the gigantic radio telescope of Puerto Rico in photos
“That particular situation was evaluated by the engineering team and determined not to be a problem because that cable’s capacity was much higher than the load it was carrying, which really shouldn’t have been a problem,” Cordova said. “Of course now with this failure, we understand that that capacity is simply not there and that there has been another degradation.”
Nestled in a natural basin in the middle of the Puerto Rican jungle, the Arecibo Observatory began scientific work in 1963 and is the second largest radio dish in the world. Scientists used it to confirm that pulsars are superdense neutron stars, to discover the first planets beyond our solar system, and to convey a message in the cosmos in hopes of achieving intelligent alien life. He is also Earth’s first sentinel to identify if specific asteroids are on their way to hitting the planet – and has appeared in blockbuster films such as James Bond’s “GoldenEye” and “Contact”, no less.
Arecibo was designed by a Cornell University scientist, who managed the facility until 2011, with the National Science Foundation (NSF) as the observatory’s main funder. Faced with growing budget pressure, the NSF gradually phased out its funding, transferring operations first to the Universities Space Research Association and then to the University of Central Florida, although NSF still owns the site.
But the last few years have been difficult for the observatory. In 2014, a major earthquake damaged parts of the facility, including a cable that facility managers hoped to replace later this year. In 2017, Hurricane Maria mistreated Puerto Rico, but mostly he spared Arecibo. The observatory’s heliport and the well water were vital resources for those who lived near the structure. Outside, astronomers had to wait over a week to find out that the observatory was still standing.
This year, throughout January, a series of earthquakes, the strongest, a 6.4 temblor, shook Puerto Rico and the facility was closed for inspection. As the month ended and the earthquakes with it, Puerto Ricans celebrated the New Year again, hoping the worst of the year was over, said Abel Mendez, a planetary astrobiologist at the University of Puerto Rico who regularly brings students to observe at Arecibo. Space.com – just to deal with the outbreak of the coronavirus pandemic in March.
But for the observatory, things would only get worse.
The first cable slipped out of its socket on August 10 at 2:45 am local time. During the descent, it damaged observation structures suspended above the dish, as well as digging a 30-meter-long “gash” in the fragile dish, according to a statement from the University of Central Florida, who manages the facility.
The situation became much more dire on November 6 at 7:39 pm, when a second cable – this time, one of the main cables – snapped, compromising the structural integrity of the 900 lbs. (400 kilograms) platform that looms over the dish, supporting the structure’s antennas and scientific instruments.
“Time is of the essence right now,” Mendez told Space.com. “I’m totally scared of what’s happening at the observatory right now. I’m so worried about it.”
Assessing the situation is also difficult, as it is dangerous to reach the suspended platform and the towers that anchor its support cables. “When you have access to the towers, when you have access to the platform, there are a million ways to remove a broken cable, lift a new cable, things like that,” Cordova said. “When it is not possible to access the attachment points for these cables, it becomes a great challenge.”
On the ground, Cordova said, the damage doesn’t seem as bad as it actually is.
“You don’t see much of a difference when you look at the platform – you definitely see a couple of extra cables hanging down that they shouldn’t be, they should really be pointing up and pointing down,” Cordova said. “But this is such a massive structure that even that is lost in the size of the background of the telescope platform itself.”
The same goes for damage the plate it built up during accidents, he said. “Certainly the plate is quite damaged,” Cordova said, “[but] every time you look at how big our primary reflector is and look at what the damage is, it doesn’t even seem like something insurmountable. “
The observatory has put together a number of options to stabilize the situation and is awaiting a decision by the National Science Foundation, which owns the facility, on how to proceed. “Hopefully in the next couple of days, we will have that decision,” Cordova said.
Meanwhile, scientists connected to the Arecibo Observatory are hoping for the best. The researchers are also gathering in regular virtual meetings, which Mendez described as “stress relief” sessions, to talk about the situation and share memories of the facility.
“This is clearly an extremely troubling situation,” Don Campbell, who began his career at Arecibo in 1965 and ultimately served as director of the observatory in the 1980s, told Space.com. “The first cable failure was definitely a surprise and cause for concern … With the second cable failure, things obviously got much more serious.”
At risk is not only the Observatory’s half-century history of research which embraces astronomy, studies on the atmosphere, asteroids close to Earth and the search for life beyond the Earth. More worrying, the scientists say, is the possibility of losing a unique facility with a lot of work to do.
“Arecibo is still a telescope that is at the forefront of many areas and its loss would be huge,” Campbell said. “I’m really crossing all my fingers to figure out how to stabilize the structure and get it repaired. I’m still a little confident.”
“It’s a precarious situation,” he added, “and we just have to wait and see.”
Email Meghan Bartels at [email protected] or follow her on Twitter @meghanbartels. Follow us on Twitter @Spacedotcom and on Facebook.
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