World News – CA – The Arecibo Observatory Grand Dish has reached the end of the line

John Timmer
– November 19, 2020, 6:10 PM UTC

The National Science Foundation today announced the closure of its popular Arecibo radio observatory. Built on a hilltop in Puerto Rico, the observatory’s main dish is over 300 meters wide and its sheer size has made it a feature in popular culture from James Bond movies to video games.. But despite a long history of scientific contributions, the observatory has struggled for funding for more than a decade, and the two cables supporting it have failed this year, leaving it in an unstable state..

After engineering studies decided that there was no way to repair the devices without putting workers at risk, the National Science Foundation made a decision to close the observatory.

While the large size of the Arecibo main course attracted the most attention, the dish was merely a reflector. The end of the actual work of the telescope, in which radio waves were detected, was an instrument platform suspended above it by cables anchored from three towers.. The device’s platform contains a receiver that can be moved to various locations above the disk, giving it the ability to resolve signals from more directions than a stationary plate might suggest.

Since its inception in the 1960s, the observatory has played a role in many discoveries, primarily in the field of pulsars, a class of radio-emitting neutron stars. She has also participated in SETI searches, submitting a photo to a star group on the assumption that any smart life out there might participate in her SETI program.. But over the past 15 years or so, the National Salvation Front, Arecibo’s primary support, cut its funding to the observatory, which has struggled to maintain its full operations during this period.. .

But it wasn’t money that ultimately wiped out Arecibo; Instead, it was the tools platform. In August of this year, one of the auxiliary cables that help support the platform was cut off, causing a wound to the radio reflective plate below.. While making plans to replace this cable and repair the dish – replacement cables were already in order – one of the seven. The main cables were cut 5 cm on the same tower on November 6.

A later engineering analysis determined that this cable failure occurred despite the fact that the stress on it was only about 60 percent of what should be the minimum breaking strength. This raised serious questions about the stability of the remaining cables, and thus the chassis’s ability to support its hardware platform. The analysis concluded that it is not safe to know; The platform can collapse without warning, and any broken cables will pose a risk to any operator in the towers, as large cables will move at very high speeds after a break. . Of three additional engineering firms that NSF and University of Central Florida consulted, two agreed with this assessment.

“Until these assessments were submitted, our question was not whether the observatory should be fixed but how,” said Ralph Guillaume of the NSF. «  But in the end, the abundance of data showed that we simply could not do it safely. This is a line that we cannot cross.

For now, the National Science Foundation simply announces that it will begin planning the decommissioning process. Work was already underway to move data archives from the device to the cloud, and it is clear that plans to safely remove the platform will include a lot of additional engineering analyzes.. The NSF said many other science programs associated with the site will remain open. The observatory also functions as a major center of communication between the scientific community and the Puerto Rican community – understanding how to maintain this dynamic in the absence of an active tool will also require further study..

It’s hard to argue with risk analysis. And it’s not hard to imagine that more modern and flexible tools can achieve the science we expect from Arecibo at a lower cost, which explains why Arecibo has struggled with funding for over a decade.. Given these two factors, it is clear that the time for Arecibo has come.

CNMN Group
Wired Media Group
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