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Snapped Cable Damages Arecibo observatory radio telescope:

DWG

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I heard there was a gash in the dish, but that's a bit more damage than I'd been anticipating.
 

Orionblamblam

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There are a number of craters on Lunar Farside that would make *fantastic* sites for replacements.
There is also one in Arizona but that might be frowned on. ;)

There are also some decent craters in Nevada. The Sedan Crater might make for a nice site for a slap-dash radio telescope. But in the long run, Lunar craters are better choices. Less radio noise and longer time-on-targets. Not to mention: building a telescope in Nevada gets you a telescope. Building a radio telescope on the Moon gets you the universe.


 

Orionblamblam

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I heard there was a gash in the dish, but that's a bit more damage than I'd been anticipating.

Apart from the damage to the instruments, I wonder jsut how much actaul loss there would be if they fired up the scope now. The total percentage of area lost seems quite small.
 

DWG

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I heard there was a gash in the dish, but that's a bit more damage than I'd been anticipating.

Apart from the damage to the instruments, I wonder jsut how much actaul loss there would be if they fired up the scope now. The total percentage of area lost seems quite small.

True, but how much more is subtly distorted out of spec?
 

Orionblamblam

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True, but how much more is subtly distorted out of spec?

That may be a bit more troublesome, but I'm honestly unclear how touchy radio telescopes are about distortions in the reflector geometry.

Vaguely related: the main reflecting mirror of the 107-inch Harlan Smith Telescope in Texas got capped by a worker what who went buggo. And getting shot seven times with a 9mm handgun did little to actually damage the functionality of the scope. Fifty years after the event, the scope and the mirror - which was only two years old at the time - are still working along.
 

Grey Havoc

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Flyaway

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Observatory officials are still determining the full extent of the damage, as well as a cost and schedule estimate for the repairs, but Johnson didn’t expect the telescope to be up and running soon. “This is going to be several months, certainly, that the antenna is going to be out of operation,” he said.

The repair work will be led by the NSF. “We’re here to support them in understanding what it is going to take,” he said, adding that none of the radar equipment used by NASA appears to have been damaged in the accident.

With Arecibo out of service, NASA is temporarily without a radar to aid in its planetary defense efforts. However, Johnson said that work replacing the radar system on a Deep Space Network antenna in California is nearing completion. A new klystron, which generates the radio signals used by the radar, has been installed on the antenna, and he estimated the radar should be in operation as soon as the end of the month.

 

Flyaway

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More to the above:


 

FighterJock

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More to the above:



Not good news for Arecibo, does anyone know what caused the cable to snap? Old age? These cables have been supporting the radio dish since Arecibo was opened.
 

FighterJock

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Arecibo is at risk of collapsing.


What will happen now if Arecibo collapses? Will they build a replacement? I cannot see the astronomers that run Arecibo let the site not be used again. It is sad that this has happened. :(
 

Flyaway

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Arecibo is at risk of collapsing.


What will happen now if Arecibo collapses? Will they build a replacement? I cannot see the astronomers that run Arecibo let the site not be used again. It is sad that this has happened. :(
I have a feeling it wouldn’t be. I point the finger at the NSF over this situation as had they been more willing to fund the maintenance of the observatory over the years, they wouldn’t be looking at a more substantial bill now. That’s of course if they don’t just wash their hands of it deciding that it’s to costly a repair.
 

TomS

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Prudence would govern to backup this analysis with a complementary one. Usually when a cable snaps, you don't take down the bridge...

The problem undoubtedly is the same as the reason the cables snapped in the first place. No money for maintenance, much less repair. And don't count on a replacement either, despite the vague noises being made in that direction.

 

Hobbes

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Prudence would govern to backup this analysis with a complementary one. Usually when a cable snaps, you don't take down the bridge...

The initial analysis was done after the first cable snapped.

Also, after the incident engineers determined the weight it bore was only at 60% of its minimum breaking strength, and it was a calm day (no wind). Apparently the problems in the cable were deeper than suspected. This also raises concerns that the remaining 11 cables may be worn more than previously thought. No one knows if the other cables are damaged or not, or if they can carry the designed load for much longer.


After consideration and an investigation by an engineering team, the NSF concluded that there is no way to fix these problems while still maintaining the safety of any crew who would do the work. Stabilizing or replacing the cable may also accelerate the collapse. The NSF therefore decided to decommission the telescope.

When the second cable snapped, it became clear that the initial analysis was faulty. So now there's a hard choice to make: rush a repair (which would take months, several km of 8 cm-thick cable can't be bought at the local hardware shop), with the risk of a cascade failure which drops the observation platform on top of the dish, collapsing the structure on top of the buildings underneath; or do a controlled demolition that preserves the buildings and the towers.
 

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My wife and I went there about 6 or 7 years ago. It was closed that day but what we could see from the public road that's next to it was really cool. Sad to it go in this way.

China has apparently copied it and has a bigger version in operation.
 

rooster

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My wife and I went there about 6 or 7 years ago. It was closed that day but what we could see from the public road that's next to it was really cool. Sad to it go in this way.

China has apparently copied it and has a bigger version in operation.
...
 

Orionblamblam

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My wife and I went there about 6 or 7 years ago. It was closed that day but what we could see from the public road that's next to it was really cool. Sad to it go in this way.

China has apparently copied it and has a bigger version in operation.
https://www.wired.com/story/china-fast-worlds-largest-telescope-tourists/

 

Archibald

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We need an alternate timeline where the NSF (National Science Foundation) gets a larger budget and starts running a modest but sustained space program... what kind of divergence would it take ?
 

chimeric oncogene

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One wonders why the Puerto Rican government didn't promote Arecibo as an internet-free/tech free holiday resort to stimulate the local economy...
 

Hobbes

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Prudence would govern to backup this analysis with a complementary one. Usually when a cable snaps, you don't take down the bridge...

They had 3 independent analyses done
: 2 firms recommended demolition, a third was willing to take the risk.
 

Flyaway

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View: https://twitter.com/RepDarrenSoto/status/1329569674447745029


We will work with @NSF and @UCF to save #AreciboObservatory if at all possible. @RepJenniffer and I are asking Congress and federal agencies to help salvage this iconic structure, & its mission to view distant worlds & identify meteors that threaten earth.


View: https://twitter.com/RepJenniffer/status/1329894249182208000


Sent a letter w/ @RepStephMurphy & @RepDarrenSoto to the House & Senate Appropriations Committee requesting the necessary funds to safely stabilize the Arecibo telescope, a valuable scientific asset treasured by all Puerto Ricans & I'm committed to continuing work to preserve it.
 

rooster

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Is there a a temperate location in conus to build a new one? Here we go again outsourcing science to the chinese
 

Hobbes

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You don't want an antenna with limited steerability at high latitudes: Arecibo's unique value lies in its powerful radar (1 MW), which is used to study the planets and asteroids. These are mostly in the ecliptic plane, which means you need to be close to the equator to see them.
 

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