An ongoing investigation into the collapse of the iconic radio telescope in December Arecibo Observatory in Puerto Rico provides early evidence that a production issue contributed to the failure.
The telescope’s massive science platform, which weighed 900 tons, was suspended with three dozen cables above the large radio dish. But in August 2020, one of them cables slipped out of his socket; before the failure could be repaired, a second cable broke straight in November. The U.S. National Science Foundation (NSF), which owns the site, determined the platform was too unstable to recover safely and decided to deprive the instrument. Before that could happen, the telescope collapsed on its own on December 1st.
Engineers have been inspecting the cables since August and crew members have been cleaning up the rubble and monitoring the environmental concerns since the crash, Francisco Cordova, director of the Observatory, said today (January 21). “The clearance of the site and the removal of debris is really underway,” Cordova told the panel, which focuses on small solar system objects such as asteroids, to notify the National Academy Committee compiling the document compiling the priorities of planetary science for the next year will form. decade. “Overall, I think it’s moving in the right direction.”
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Cordova noted that the azimuth arm of the telescope, which helped steer its instruments, and the hanging dome hung from it that held antennas and the facility’s radar transmitter, has already been removed from the site. Environmental engineers have also collected two types of potentially hazardous materials used on the platform, he said.
The next priority is to clean up remaining platform debris; to reach the material, work crews deconstructed part of the massive Arecibo reflector dish, which is 305 meters wide. The observatory team is also evaluating how much of the dish can be saved, Cordova said.
“There is still a lot of discussion about how much of the primary reflector can be saved and how we are going to work,” Cordova said. “Our focus right now is to safely remove the platform structure, and then we’ll look into it.”
At the same time, two forensic investigations are being conducted that caused the collapse of the telescope. One investigation focuses on the so-called auxiliary cables. These 12 cables were added in the 1990s when the observatory installed the massive hanging dome that distinguished the country. telescope appearance in the movie “Contact” from his previous cameos in James Bond’s “GoldenEye”. The first cable to fail was one of these auxiliary cables that slipped out of the socket where it was connected to one of the three support towers around the dish.
“Preliminary investigation revealed that there was a manufacturing defect in the cables – in particular, the connection procedure was not done properly, and this led to advanced deterioration of the specific structural element,” Cordova said. “But the final forensic investigation has yet to be completed.”
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A second forensic investigation focuses on the main cables that were originally for the construction of the telescope in the early 1960s. It was one of those main cables that cut in November, despite estimates by engineers that it carries only 60% of the weight it could withstand.
While they are working, the engineers separate the site debris that may be relevant to the two forensic investigations. In addition, Cordova said staff are evaluating that debris is removed for possible historical interest so items can be salvaged.
Both the clean-up and investigation processes continue, Cordova stressed; In addition, the NSF is working separately on understanding the collapse and evaluating the future of the site, including for report requested by Congress by the end of February.
And the answer may never be crystal clear. “There is certainly not one item that contributes, but a multitude of items that contributed to the specific failure,” Cordova said. In addition to the age of the facility, Puerto Rico has been difficult over the past few years. In 2017, Hurricane Maria hit the island, and over the course of 2020, it will experience more than 10,000 earthquakes.
“Actually, we were shaking all the time; that could definitely have been a factor,” Cordova said. “It is still being analyzed by the engineering teams.”
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