News published 20-010
NSF plans to demolish Arecibo Observatory’s 305-meter telescope due to safety concerns
Aresibo Observatory’s 305-meter telescope in November 2020.
November 19, 2020
Following a review of engineering assessments that damaged the Ericabo observatory, the facility’s construction workers and employees could not be stabilized without risk, U.S. The National Science Foundation will begin plans to dismantle the 305-meter telescope, which has been in operation for 57 years. World class resource for radio astronomy, planetary, solar system and geospatial research.
The decision came after the NSF evaluated multiple assessments by independent engineering companies that found that the telescope structure was in danger of catastrophic failure and that its cables would no longer be able to carry the load designed to support them. Moreover, many assessments have stated that any attempt at repair could put workers at potentially life-threatening risk. Even in the event of repairs proceeding, the engineers discovered that the structure would present long-term stability issues.
“NSF prioritizes the safety of workers, Arecibo Observatory staff and visitors, which, unfortunately, makes this decision necessary,” NSF director Sethuraman Panchnath said. “For nearly six decades, the Arecibo Observatory has served as a disorder for progress science and what partnership with the community might look like. While this is a profound change, we will look for ways to help the scientific community and keep it strong. People from Puerto Rico Relationship with. “
Engineers have been testing the Arecibo Observatory 305-meter telescope since August Gust, when one of its support cables fell apart. The NSFA authorizes the University of Central Florida to operate the CI Recipes, taking all reasonable steps to deal with the situation and ensuring the safety of the use of available funds, while safety remains the highest priority. UCFA acted quickly, and the evaluation process followed its expected timeline, age of the facility, design complexity, and potential risk to workers.
The engineering teams designed the emergency structural stabilization of the auxiliary cable system and prepared to implement it. While the observatory was arranging the delivery of two replacement auxiliary cables, as well as two temporary cables, one of the main cables was housed on the same tower. Broken on the 6th, depending on the tension on the second broken cable – which should be good inside it. Ability to work without breaking – Engineers conclude that the rest of the cables are weaker than originally estimated.
“The leadership of the Arecibo Observatory and the UCF have done a commendable job considering this situation, working quickly to salvage this incredible tool and pushing every possible option forward,” said Ralph Gaume, Director of Astronomical Sciences at NSF. “Until these assessments came our question was not how the observatory should be repaired but how. But in the end, the progress of the data shows that we can’t do this safely. And that’s a line we can’t cross.” . “
The scope of the NSF’s demolition plan will focus only on the 305-meter telescope and is intended to safely preserve other parts of the observatory that could be damaged or destroyed in the event of an unplanned, catastrophic collapse. The plan aims to maintain as much of the remaining infrastructure of the Arecibo Observatory as possible, so that it remains available for future research and educational missions.
The decomposing process involves developing a technical implementation plan and ensuring compliance with a range of legal, environmental, safety and cultural requirements in the coming weeks. The NSFA has authorized high-resolution photographic surveys using drones, and is considering options for forensic evaluation of broken cables – if such action can be taken safely – to see if any new evidence can inform ongoing plans. This work has already begun and will continue throughout all demolition planning. Equipment and other materials will be temporarily moved to buildings outside the risk area. When all the necessary preparations have been made, the telescope will be subject to controlled discharge.
Following the demolition of the telescope, the NSF intends to re-establish operations at the Arecibo Observatory LIDAR facility – a valuable geospace research tool – as well as properties that analyze cloud cover and rainfall data, such as the Visitor Center and the Ite Fasite Colebra facility. The NSF will also explore the possibilities for expanding the educational capabilities of the education center. Safety precautions due to the COVID-19 epidemic will be in place.
Analysis of the archived data collected by the telescope and some of the archibo operations associated with the catalog will continue. UCF secured enhanced cloud storage and analytics capabilities in 2019 through an agreement with Micro .ft, and the observatory is working to transfer site data to servers outside the affected area.
Fields of the observatory affected by the uncontrolled collapse have been evacuated since the November cable break and will remain closed to unauthorized personnel during the bankruptcies. The NSF and UCF will work to reduce risk in the region in the event of an unexpected collapse. In order to avoid such an incident, the NSFA has preferred a quick and thorough process.
The NSF recognizes the cultural and economic significance of Puerto Rico from the Arecibo Observatory, and how the telescope is an inspiration to the Puerto Ricans in terms of education and employment at SETEM. The NSF aims to work with the Puerto Rican government and other stakeholders and partners to explore the possibility of applying resources from the Arecibo Observatory for educational purposes.
Michael Wiltberger, head of the NSF’s geospatial division, said: “Throughout its lifetime, the Arecibo Observatory has helped transform our understanding of the ionosphere, showing how densities, formations and other factors have shaped the Earth’s atmosphere. Interacts with. ” “While I am disappointed with the loss of investigative capabilities, I believe this process is an essential step in maintaining the research community’s ability to utilize the Arecibo Observatory’s other assets and hopefully ensure that important work can continue at the facility.”
Engineering Summary
In the Arecibo Observatory’s telescope, a radio dish with a 90,000-ton instrument platform hanging above the radio is 100 feet (50 meters) wide. The platform is suspended by cables connected to three towers.
10 On August 20, 2020, the auxiliary cable failed, it slipped from its socket into a tower and placed a 100-foot gasket in the bottom dish. The NSFA has authorized the Arecibo Observatory to take all reasonable steps and use the available funds to secure the analysis and equipment needed to meet the situation. The same engineers were working to determine how to repair the damage and determine the integrity of the structure when the main cable connected to the same tower broke on November 6.
Another broken cable was unexpected – an engineering assessment following auxiliary cable failure indicated that the structure was stable and plans were underway to restore the telescope to operation. Engineers then discovered that this 3-inch main cable had broken about 60% of its minimum breaking capacity it should have during periods of calm weather, making other cables more likely to be weaker than expected.
Investigations of other cables revealed new wires on some of the main cables that were original in the structure, and evidence that some of the sockets containing the remaining auxiliary cables were significantly slippery, added during the refit in the 1990s, adding weight. Instrument platform.
Runton Tomasetti, an engineering firm of records taken by UCF to assess the constitution, found that, given the possibility of another cable failing, repair work on the telescope – including reduced measures to stabilize it for additional work – would be unsafe. Thornton Tomasetti has discovered that stress tests can break the structure to get a more accurate measure of the power of the remaining cables. The firm recommended controlled demolition to eliminate the risk of an unexpected collapse.
“While we are saddened by this recommendation, we believe that the practice should be curtailed as soon as possible,” Thornton said in a letter of recommendation submitted by Tomasetti. “It is therefore our advice to plan for the demolition of the observatory quickly and to implement a telescopic controlled demolition.”
UCFA also hired two other engineering companies to provide an assessment of the situation. One recommended immediate stabilization action. The second, after reviewing Thornton Tomasetti’s model, agreed that there was no course of action that could safely test the stability of the structure and advised against allowing the telescope to staff on the platform or tower.
UCF President Alexander N. “Critical work remains to be done in the fields of atmospheric science, planetary science, radio astronomy and radar astronomy,” Cartwright said. “UCF is ready to use its experience with the observer to engage other stakeholders to follow the type of commitment and funding required to continue and build Arecibo’s contribution to science.”
After receiving the evaluation of the contract, the NSF brought in an independent engineering team and Army Corps Engineers to review the findings. Penny NSF Jobs agreed with Thornton Tomasetti’s recommendations and expressed concern about the significant danger of an uncontrolled collapse. Engineers Army Corps has recommended additional photographic evidence of the facility and a full forensic evaluation of the broken cable.
Workers must be on or near the telescope structure due to any stabilization or repair scenario, the degree of uncertainty about the power of the cables and the extreme forces at work, accepting the recommendation of NSF 305- to prepare for controlled demotion. Meter telescope.
-NSF-
Media contacts
Media Affairs, NSF, (703) 292-7090, Email: [email protected]
U.S. The National Science Foundation will take the nation forward by advancing basic research in all fields of science and engineering. The NSF supports research and people by providing facilities, equipment, and funding to support their ingenuity and sustain the U.S. as a global leader in research and innovation. With a budget of 8 820 billion for fiscal year 2020, NSF funding reaches all 50 states through grants to about 50 colleges, universities and institutions. Each year, the NSF receives more than 40,000 competitive proposals and awards 11,000 new prizes. The awards include support for industry, Arctic and Antarctic research and operations, and cooperative research with U.S. participation in international scientific endeavors.
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