Four years after the radio telescope at Puerto Rico’s Arecibo Observatory collapsed. Report from the National Academies of Sciences, Engineering, and Medicine sheds light on the unprecedented failures that led to its destruction.
A steel cable supporting the telescope’s 900-ton receiver platform came loose after a zinc-filled socket built to support it failed, according to a report released Oct. 25. That’s what it means.
The report said the failure was caused by excessive “zinc creep,” a phenomenon in which the metal used to protect the socket from corrosion and rust deforms over time and loses its grip.
The zinc gradually lost its hold on the cable suspending the telescope’s main platform above the reflector dish. This caused multiple cables to be pulled from their sockets, ultimately causing the platform to crash into a reflector more than 400 feet below, according to the report.
Roger L. McCarthy, chairman of the committee for the analysis of the causes of failure and collapse of Arecibo’s 305-meter telescope, said, “This type of failure has been the most common occurrence in more than a century, when zinc spelter sockets have been widely and successfully used. This has never been reported before.” The observatory wrote in its report:
The committee that prepared the report said there was insufficient data to definitively prove the exact cause of the acceleration of “zinc creep.” The only hypothesis the committee was able to develop based on the data was that low current electroplastic effects were responsible. In other words, the constant current flowing through the socket could have strengthened the plastic behavior of the metallic zinc and, as a result, weakened its grip.
The committee reviewed an array of documents commissioned by the University of Central Florida and the National Science Foundation, the federal agency that owns the observatory, including a forensic investigation, structural analysis, engineering plans, inspection reports, photographs, and repair proposals. Reach that conclusion. They also gathered information from Arecibo Observatory employees, other “related research” sources, and the National Academies of Sciences, Engineering, and Medicine. I mentioned this in a media advisory last month..
The commission also issued a series of recommendations in its report. These include making the remaining sockets and cable sections of the radio telescope available for further research and increasing careful monitoring of aging research facilities to detect deterioration and potential new failure modes. Included.
The telescope was used to track asteroids as they headed toward Earth, conduct research that led to Nobel Prizes, and determine whether planets were potentially habitable. It also functions as a training venue for graduate students, and is visited by approximately 90,000 people annually.
The telescope was built in the 1960s with funding from the Department of Defense during the development of ballistic missile defense. In its 57 years of operation, it has withstood hurricanes, tropical humidity, and a recent series of earthquakes.
The observatory began to collapse in August 2020 when an auxiliary cable snapped, damaging the telescope’s antenna and the receiver platform suspended above it, according to the National Science Foundation. After several other cable failures, the federal agency decided to begin a plan to decommission the telescope in November 2020.
This transition did little to stop the telescope’s complete collapse on December 1, 2020.
In 2022, the National Science Foundation says: Puerto Rico’s famous radio telescope won’t be rebuilt. Instead, it called for a $5 million education center to be established in its place to promote programs and partnerships related to science, technology, engineering and mathematics.
Source: www.nbcnews.com
