Iconic Arecibo Observatory to be demolished after cable damage

20 Nov 2020

Image: © PhotoSpirit/Stock.adobe.com

One of the most recognisable radio telescopes on Earth is being decommissioned after a series of incidents left it damaged beyond repair.

The US National Science Foundation (NSF) has announced that, following a number of engineering assessments, the Arecibo Observatory on the island of Puerto Rico will be decommissioned after 57 years of service.

The 305-metre radio telescope, made internationally famous by movies such as GoldenEye and Contact, was found to be in danger of a catastrophic failure as its cables may no longer be capable of carrying the loads they were designed to support.

An incident in August of this year saw a cable slip out of its socket, potentially putting the telescope and astronomers in danger. Not long after, it was reported that a second cable had snapped, forcing the NSF to evaluate how to repair it.

‘A beacon for breakthrough science’

Inspections of the other cables revealed new wire breaks on some of the main cables, which were original to the structure. There was also evidence of significant slippage at several sockets holding the remaining auxiliary cables, which were added during a refit in the 1990s that added weight to the instrument platform.

However, the NSF confirmed that even if repairs were made to Arecibo, the structure would present long-term stability issues.

“NSF prioritises the safety of workers, Arecibo Observatory’s staff and visitors, which makes this decision necessary, although unfortunate,” said NSF director Sethuraman Panchanathan.

“For nearly six decades, the Arecibo Observatory has served as a beacon for breakthrough science and what a partnership with a community can look like.”

‘It saddens us to make this recommendation’

While the main telescope will be decommissioned, the NSF said it intends to safely preserve other parts of the observatory that could be damaged or destroyed in the event of an unplanned, catastrophic collapse.

Vital equipment is being temporarily moved to secure locations. Following a drone survey and forensic evaluation to better understand why the cables snapped, the Arecibo telescope will undergo a “controlled disassembly”.

A letter submitted by the engineering firm tasked with evaluating the site, Thornton Tomasetti, said: “Although it saddens us to make this recommendation, we believe the structure should be demolished in a controlled way as soon as pragmatically possible.”

Commenting on Arecibo’s contribution to our understanding of the universe, Michael Wiltberger, head of NSF’s geospacer section, said: “Over its lifetime, Arecibo Observatory has helped transform our understanding of the ionosphere, showing us how density, composition and other factors interact to shape this critical region where Earth’s atmosphere meets space.”

Colm Gorey was a senior journalist with Silicon Republic