Broken Cable Damages Arecibo

ucf.edu

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One of the auxiliary cables that helps support a metal platform in place above the Arecibo Observatory in Puerto Rico, broke on Monday (Aug. 10) causing a 100-foot-long gash on the telescope’s reflector dish. Operations at the UCF-managed observatory are stopped until repairs can be made.

The break occurred about 2:45 a.m. When the three-inch cable fell it also damaged about 6-8 panels in the Gregorian Dome and twisted the platform used to access the dome. It is not yet clear what caused the cable to break.

“We have a team of experts assessing the situation,” says Francisco Cordova, the director of the observatory. “Our focus is assuring the safety of our staff, protecting the facilities and equipment, and restoring the facility to full operations as soon as possible, so it can continue to assist scientists around the world.”

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The photo with the article is pretty shocking.

It takes quite a lot to break a cable that size, but I wouldn't be too surprised if it was a combination of fatigue damage due to wind (vortex shedding) and the vibration from the earthquakes combined with corrosion. One would have to see where the cable broke and get a microscopic examination of the area of rupture.

Scott Manley has a video about the break and it looks like (maybe) the failure was at the point where the cable connects to the base way off to one side of the telescope itself.

https://youtu.be/4V3VCt24tkE

The Verge

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The world-famous Arecibo Observatory in Puerto Rico, known for helping scientists peer into deep space and listen for distant radio waves, is set to be decommissioned and demolished after engineers concluded that the facility’s structure is at risk of a collapse. While teams will try to salvage some parts of the observatory, the decommission will bring an end to the popular 57-year-old telescope, which has been featured in numerous films and television shows.

The decision comes after two major cables failed at the facility within the last few months, causing significant damage to the observatory. The National Science Foundation (NSF), which oversees Arecibo, assessed the impact of the cable breaks and found that the facility’s other cables could also fail soon. If some of the remaining cables break, engineers fear that the 900-ton suspended platform above the facility could come crashing down on Arecibo’s iconic 1,000-foot-wide dish. It’s also possible that three surrounding towers, which stand at more than 300 feet tall, could topple over in any direction, potentially hitting the visitor’s center or other important nearby buildings.

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Very sad news.

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Originally Posted by Swift

The Verge

Very sad news.

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I hate this year. Mostly, anyway.

Very sad. Another article:

https://astronomy.com/news/2020/11/f...cable-failures

They say it should be demolished, but not whether it could be rebuilt in the same natural depression afterwards. Would there be anything to prevent that?

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Originally Posted by KaiYeves

Would there be anything to prevent that?

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Money

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Originally Posted by Swift

Money

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No, I mean physically, as in whether the current telescope structure has altered the land in any way that would make a similar construction later on not feasible? That sort of thing.

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Originally Posted by KaiYeves

They say it should be demolished, but not whether it could be rebuilty in the same natural depression afterwards. Would there be anything to prevent that?

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Possible sure, but they’ve had trouble keeping it funded as is, and I’ve heard they considered shutting it down earlier. I would bet that this wouldn’t have happened if they had reasonable maintenance funding. My hunch is that maintenance was cut to the bone.

Ugh. I'm very saddened to read this news. :( That installation was a national treasure. It certainly ranks as an major astronomy icon as much as the Hubble. Moreover, this will probably result a blind spot in tracking near earth asteroids.

It was a marvel of engineering when it was built. Hopefully they can take it down safely.

The facility is co-managed by the University of Central Florida near Orlando. Here's the latest from UCF:

https://www.ucf.edu/news/arecibo-obs...d-cable-break/

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Following a review of engineering assessments, the U.S. National Science Foundation today announced it will begin planning 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 agreement, has for 57 years served as a world-class resource for radio astronomy and planetary, solar system and geospace research. But a main cable break on Nov. 6 caused the structural integrity of the telescope to come into question.

Three engineering firms, which had been previously hired to address an auxiliary cable break at the facility in August, assessed the telescope and submitted their reports to NSF. The engineer of record, Thornton Tomasetti, recommended decommissioning of the telescope because it found the telescope structure is in danger of a catastrophic failure. NSF had two other groups review the assessments, and they concurred that pursuing repairs posed a risk to human life.

“Our team has worked tirelessly with the NSF looking for ways to stabilize the telescope with minimal risk,” says UCF President Alexander N. Cartwright. “While this outcome is not what we had been working towards, and we are disheartened to see such an important scientific resource decommissioned, safety is our top priority. At a time when public interest and scientific curiosity about space and the skies has re-intensified, there remains much to understand about the data that has been 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 safety plans and authorizations needed to begin the decommissioning process. The work is not expected to begin for several weeks. The goal is to bring down the telescope, which includes the platform and Gregorian Dome and keep as many other parts of the facility intact for future use.

NSF says it intends to restore the LIDAR facility, which is used in geospatial research at Arecibo as well as the visitor center and the offside Culebra research substation, which analyzes cloud cover and precipitation data.

“NSF prioritizes the safety of workers and 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. While this is a profound change, we will be looking for ways to assist the scientific community and maintain that strong relationship with the people of Puerto Rico.”

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Originally Posted by KaiYeves

No, I mean physically, as in whether the current telescope structure has altered the land in any way that would make a similar construction later on not feasible? That sort of thing.

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I don't see how. Land/rock formations are fairly stable absent landslides or eruptions or the like. And the existing towers may well be in good shape, leaving open the potential for incorporating them into a future telescope design.

Very sad. And almost certainly preventable, if only sufficient funds had been available for maintenance.

Trebuchet...

In my experience working with government agencies, there never seems to be enough money for maintenance. Funding NEW is always more popular than maintaining OLD or fixing OLD. I think the same is true for most individuals, myself included. ;)

I am a civil engineer and have encountered this many times in my 40+ year career. One community services district I consulted for years ago had only about 10% of the funds they needed for annual road maintenance. Needless to say, their roads were falling apart, but they somehow had money for a new community center when the old one was still in good shape. Of course, the sources of these funds were different, but the governing board still preferred to spend on NEW, while the general manager was trying to get their focus back to maintenance and repair of OLD. He soon quit in frustration.

In the early 2000s, I got involved in the civil side of adding new buildings to several existing state prisons. A court had determined that the state was not meeting its mental health obligations to inmates, and thus required the state to spend tens of millions of dollars on new buildings at existing prisons that were in varying conditions of adequate to disrepair. The state had been saying for years there wasn't any money for maintenance (their budgets showed it and long conversations with the maintenance supervisors at four of the state prisons confirmed it), yet they somehow found the funds to build NEW. I guess courts are more persuasive than your own maintenance supervisors.

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Originally Posted by geonuc

I don't see how. Land/rock formations are fairly stable absent landslides or eruptions or the like. And the existing towers may well be in good shape, leaving open the potential for incorporating them into a future telescope design.

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I think they'll probably bring down the towers to drop the whole thing in a controlled fashion without the cables whipping around, but they wouldn't make that much difference to the cost of a replacement. The problem is that if they had the kind of money required for a replacement, they'd have been able to maintain it properly and keep the original running.

Maybe they can put up some small dishes. There's a lot of infrastructure there beyond the dish itself and the location itself is already radio-quiet, and keeping it active even with much smaller scale instruments would make it more feasible to rebuild a large telescope there at some future time if funding becomes available.

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Originally Posted by skysurfer5cva

Trebuchet...

In my experience working with government agencies, there never seems to be enough money for maintenance. Funding NEW is always more popular than maintaining OLD or fixing OLD. I think the same is true for most individuals, myself included. ;)

I am a civil engineer and have encountered this many times in my 40+ year career. One community services district I consulted for years ago had only about 10% of the funds they needed for annual road maintenance. Needless to say, their roads were falling apart, but they somehow had money for a new community center when the old one was still in good shape. Of course, the sources of these funds were different, but the governing board still preferred to spend on NEW, while the general manager was trying to get their focus back to maintenance and repair of OLD. He soon quit in frustration.

In the early 2000s, I got involved in the civil side of adding new buildings to several existing state prisons. A court had determined that the state was not meeting its mental health obligations to inmates, and thus required the state to spend tens of millions of dollars on new buildings at existing prisons that were in varying conditions of adequate to disrepair. The state had been saying for years there wasn't any money for maintenance (their budgets showed it and long conversations with the maintenance supervisors at four of the state prisons confirmed it), yet they somehow found the funds to build NEW. I guess courts are more persuasive than your own maintenance supervisors.

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Yup. There's never enough time or money to do it right, but there's always enough to do it over.

I wonder if Meteor Crater might be a better location for a replacement

As it’s the 25th anniversary of GoldenEye, perhaps they could get some money by reaching out to the stars of that film?

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Originally Posted by publiusr

I wonder if Meteor Crater might be a better location for a replacement

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It would be pretty cool to have a replacement in Meteor Crater Arizona, but I think that the SKA is going to fill the need for Arecibo pretty well without the need for a single large spherical dish.

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Originally Posted by skysurfer5cva

Trebuchet...

In my experience working with government agencies, there never seems to be enough money for maintenance. Funding NEW is always more popular than maintaining OLD or fixing OLD. I think the same is true for most individuals, myself included. ;)

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Unfortunately it is equally true in private industry.

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Originally Posted by antoniseb

It would be pretty cool to have a replacement in Meteor Crater Arizona, but I think that the SKA is going to fill the need for Arecibo pretty well without the need for a single large spherical dish.

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And the planned locations, like Arecibo, are relatively low on nearby background radio waves so less RF noise to filter.

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Originally Posted by antoniseb

It would be pretty cool to have a replacement in Meteor Crater Arizona, but I think that the SKA is going to fill the need for Arecibo pretty well without the need for a single large spherical dish.

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As far as I've been able to determine, the SKA has no elements capable of transmitting. Any radar astronomy with it would require a big dish elsewhere as transmitter. And while you can improve sensitivity by arraying antennas, it's not going to be the same as a dish of equivalent area. I wouldn't be surprised if Arecibo could pick up signals that the SKA won't be able to.

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Originally Posted by antoniseb

It would be pretty cool to have a replacement in Meteor Crater Arizona, but I think that the SKA is going to fill the need for Arecibo pretty well without the need for a single large spherical dish.

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Could it be dual use, with a more solid central tower and mirrored panels that can slide, cable free?
Feed horn by night, solar power tower by day?

The Southern Hemisphere needs more love in terms of dish space.

Meteor Crater would allow for a dish a mile across or so—besting FAST.

HEY BEZOS!!!

Something else—-could Starshot also benefit from a big dish...a three use facility? More?

I confess I haven't looked, but have they said WHY the cables failed? My first guess would be corrosion. That should have been preventable.

Maybe wind turbines to go on the towers? Lighter cables for the ultimate H.A.M. radio?

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Originally Posted by Trebuchet

I confess I haven't looked, but have they said WHY the cables failed? My first guess would be corrosion. That should have been preventable.

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Since then I saw a Scott Manley video (sorry, no link handy) saying that in one case the cable pulled out of a spelter socket. That's a standard method of making up cables ends by inserting the cable into a fitting, brooming out the wires, and pouring in molten zinc. Possibly made wrong decades ago. The other one was definitely corrosion.
It sounds like they can't even save the equipment out on the platform, will just drop it into the bowl. Very sad.

The great telescope has collapsed as of today. Damage is severe.

https://phys.org/news/2020-12-huge-p...telescope.html

Photo in this tweet.

https://mobile.twitter.com/deborahti...47356605571072

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Originally Posted by antoniseb

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Originally Posted by publiusr

I wonder if Meteor Crater might be a better location for a replacement

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It would be pretty cool to have a replacement in Meteor Crater Arizona, but I think that the SKA is going to fill the need for Arecibo pretty well without the need for a single large spherical dish.

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While I really would like to see Arecibo replaced, I would hate for an important geological site like Meteor Crater be destroyed to accomplish that. I also can't believe it would make that much of a difference in cost.