It’s the end of the iconic 1,000-foot-wide telescope at Arecibo Observatory after the second cable break

The National Science Foundation predicts that it will be several weeks before disassembly of the telescope can begin.

Following a review of technical assessments, the US National Science Foundation announced that it has begun planning for the controlled decommissioning of the 1,000-foot-wide telescope at the Arecibo Observatory in Puerto Rico.

The observatory, which UCF manages for NSF under a cooperative arrangement, has served for 57 years as a world-class resource for planetary, solar system and geospatial radio astronomy and research. But a main cable break on November 6 called the structural integrity of the telescope into question.

Three engineering firms, which had previously been hired to fix an auxiliary cable break at the facility in August, evaluated the telescope and submitted their reports to the NSF. Reference engineer Thornton Tomasetti recommended decommissioning the telescope as he found the telescope structure to be in danger of catastrophic failure. NSF asked two other groups to review the assessments and they agreed that continued repairs posed a risk to human life.

“Our team has worked tirelessly with the NSF to find ways to stabilize the telescope with minimal risk,” says UCF President Alexander N. Cartwright. “While this result does not meet our goal and we are discouraged to see such an important scientific resource decommissioned, safety is our top priority. At a time when public interest and scientific curiosity for space and the sky have intensified, there is still a lot to understand about the data acquired by Arecibo. Despite this disappointing setback, we remain committed to the scientific mission in Arecibo and to the local community.

UCF will work with NSF to implement the security plans and clearances necessary to begin the decommissioning process. The work should not start for several weeks. The goal is to knock down the telescope, which includes the platform and the Gregorian dome, and keep as many other parts of the facility intact for future use.

NSF intends to restore the LIDAR facility, which is used in geospatial research at Arecibo, as well as the Culebra Visitor Center and Offside Research Substation, which analyzes cloud cover data and the precipitations.

“NSF is prioritizing the safety of workers, staff and visitors to the Arecibo Observatory, which makes this decision necessary, albeit unfortunate,” said NSF Director Sethuraman Panchanathan. “For nearly six decades, the Arecibo Observatory has served as a beacon for disruptive science and what a partnership with a community can look like. While this is a profound change, we will be looking for ways to help the scientific community and maintain this strong relationship with the Puerto Rican people.

The beginnings of Arecibo

The Arecibo Observatory was built from 1960 to 1963 and was designed by Cornell University physicist William Edwin Gordon. Cornell University was the site’s first manager. The location was ideal for the telescope and would lead to decades of significant contributions to atmospheric science, planetary science, radio astronomy, and radar astronomy.

The enormous primary disk of the AO telescope has been a workhorse for science. It was used to discover the first exoplanets and to detect organic molecules outside of our galaxy. The 1993 Nobel Prize in Physics was awarded to Russell Hulse and Joseph Taylor for their work with Arecibo in monitoring a binary pulsar, providing a strict test of Einstein’s theory of general relativity and the first proof of the existence of gravitational waves. Arecibo also helps NASA characterize asteroids that could pose a threat to Earth through the agency’s near-Earth object observation program at the Planetary Defense Coordination Office. The installation even appeared in a James Bond film and The X-Files TV shows.

Considered a cultural treasure in Puerto Rico, the site is visited by thousands of schoolchildren each year and thousands of other visitors from around the world. The drop-in center, built with private donations, also runs several education and awareness programs throughout the year that reach out to all learners. NSF supports an undergraduate research experience program there each summer.

UCF became the manager of the facility in April 2018 after receiving a grant of $ 20.15 million over five years. This is the third year of the grant. Since arriving on board with UCF, the facility has secured new funding to continue NASA’s work and to design and guide new instruments that were to be added to the telescope over the next several years. Other scientists have also secured funding to improve Arecibo, including a 2018 grant to Brigham Young University and Cornell University for $ 5.8 million to design and assemble a hypersensitive antenna (ALPACA) in focus. focal length of the telescope antenna.

In 2019, UCF expanded its agreement with Microsoft, which allowed the observatory to access a variety of Azure services – from analytics to artificial intelligence – to develop a new platform that will facilitate access and storage of the 12 petabytes of data the observatory has collected over its 50-year history. When fully implemented, the new platform is expected to make solid information about planets, pulsars, asteroids and comets more readily available to scientists working at Arecibo and around the world. Work is underway.

The observatory continued to help scientists with observations that they turned into published journal articles that broadened our knowledge of space and the place of Earth in the solar system.

Challenges

The facility has suffered from several hurricanes and earthquakes. It was damaged in Hurricane Maria in 2017, and the Federal Emergency Management Agency used the observatory’s helicopter airstrip and other facilities as a staging ground to stock up and assist the community. UCF worked to secure funds to carry out repairs and improve the site after the hurricane. Work was in progress when the first auxiliary cable broke in August 2020.

The cable slipped from its socket in one of the towers, leaving a 100-foot gash in the dish below. A team of experts have been called in to investigate the cause of the rupture and find a way to make repairs. UCF worked with NSF to assess the breach and develop a plan. The facility was shut down and a monitoring team began to monitor all cables and the platform as part of the facility’s temporary emergency safety and repair plan. Safety was the priority throughout the assessment process. Arecibo was awaiting a team of engineers to begin temporary emergency repairs related to the August incident when the main cable broke on Friday, November 6.

Unlike the failed auxiliary cable, this main cable did not slip out of its socket. It broke and fell on the reflector dish below, causing further damage to the dish and other cables nearby. Both cables were connected to the same support tower. A security zone was set up around the antenna and only the personnel necessary to respond to the incident were authorized on site.

The second broken cable was unexpected. Engineering assessments following the failure of the auxiliary cable indicated that the structure was stable and that the planning process to return the telescope to service was underway. Engineers later found that the 3-inch main cable had broken at about 60% of what should have been its minimum breaking strength during a period of quiet time, increasing the possibility that other cables were lower than expected. Subsequent drone inspections of the other cables revealed new wire breaks on some of the main cables.

All information was shared with the NSF, which notified UCF of its decision on November 18. The next steps are still pending and UCF is committed to working with the Puerto Rican community.

“Critical work remains to be done in atmospheric sciences, planetary sciences, radio astronomy and radar astronomy,” said President Cartwright. “UCF stands ready to use its experience with the observatory to join with other stakeholders in pursuing the kind of commitment and funding needed to continue and build on Arecibo’s contributions to science. .