Author Topic: The end of the line for the Arecibo radio telescope  (Read 15149 times)

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Offline CJay

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Re: The end of the line for the Arecibo radio telescope
« Reply #1 on: November 20, 2020, 08:49:01 am »
Damn shame and it looks like it might not be rebuilt but it seems demolition is the right decision.

I wonder if they'll auction off bits of it as memorabilia
 

Offline Gyro

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Re: The end of the line for the Arecibo radio telescope
« Reply #2 on: November 20, 2020, 12:29:06 pm »
That's really sad. I would have thought that its construction would have made it ideal for cost-effective  updating or at least replacement of the entire suspended section. It's an iconic structure. :(
« Last Edit: November 20, 2020, 12:34:36 pm by Gyro »
Best Regards, Chris
 

Offline Zbig

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Re: The end of the line for the Arecibo radio telescope
« Reply #3 on: November 20, 2020, 03:17:53 pm »
I want off this fucked-up timeline so I went "Google, restart the simulation". She said she didn't understand :'(
 

Offline BravoV

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Re: The end of the line for the Arecibo radio telescope
« Reply #4 on: November 20, 2020, 03:38:22 pm »
Well, at least its now covered by -> FAST and bigger, comparison of Arecibo's size vs FAST.





Online Kleinstein

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Re: The end of the line for the Arecibo radio telescope
« Reply #5 on: November 20, 2020, 05:16:53 pm »
AFAIK the FAST dish is used under a relatively low angle, and not with the receiver suspended on top. This reduces the effective area quite a bit. So the actual effective aperture is not that much larger.

With that type of damage and an already old structure the demolition is probably the only sensible decision. Chances are there will not be money for a quick rebuild. The last extension of support was already a close call.
 

Offline BravoV

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Re: The end of the line for the Arecibo radio telescope
« Reply #6 on: November 20, 2020, 05:41:59 pm »
AFAIK the FAST dish is used under a relatively low angle, and not with the receiver suspended on top. This reduces the effective area quite a bit. So the actual effective aperture is not that much larger.


Offline coppercone2

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Re: The end of the line for the Arecibo radio telescope
« Reply #7 on: November 20, 2020, 10:49:37 pm »
is that thing made of aluminum?

I wonder why they can't fix it with careful welding and epoxy (reinforce with a epoxied frame then weld it up after its more secure. You would think they could put jacks (cranes) under it and weld it up and not let china have RF astronomy dominance.

I wonder if you can 3d-print a concrete support under it with those new 3d printer machines that make the stupid looking round concrete houses so you can work on it safely. I assume when you drill out all the cracks in the aluminum and make sure the brackets are solid you can resuspend it with stainless cable. If you could figure out how to get a printer to make that temporary support that could be demolished later it might save scientists overall money in the long run by making more weird science stuff repairable. At 900 tons its well outside of helicopter support and it looks like you would need to cut out alot of the structure on the bottom to put a bunch of cranes there. Maybe just put a new receiver up and fix the reflector later? You could probably cut out sections carefully and reuse them so you can drive equipment down there.

« Last Edit: November 20, 2020, 11:03:55 pm by coppercone2 »
 

Offline CatalinaWOW

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Re: The end of the line for the Arecibo radio telescope
« Reply #8 on: November 20, 2020, 11:38:38 pm »
Reading several different articles about this, it appears to be another case of "penny wise and pound foolish".  Between the instruments and location there is a great deal of good science that could still have been done with Arecibo, and some of it is non-overlapping/complementary with FAST.  But maintenance costs were deferred for years and now it is too late.  Some of those maintenance costs were deferred in favor of instruments that are now unusable and un-recoverable.
 
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Offline coppercone2

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Re: The end of the line for the Arecibo radio telescope
« Reply #9 on: November 21, 2020, 12:30:35 am »
lets paint that rust and patch those holes with our good will ;D

Keep in mind that is also a multi terrawatt radar, not just a telescope. It could be used to find asteroids that are heading towards earth. Now the CCP will be in charge of that  :clap:
« Last Edit: November 21, 2020, 12:39:02 am by coppercone2 »
 

Offline BravoV

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Re: The end of the line for the Arecibo radio telescope
« Reply #10 on: November 21, 2020, 04:29:33 am »
is that thing made of aluminum?

I wonder why they can't fix it with careful welding and epoxy (reinforce with a epoxied frame then weld it up after its more secure. You would think they could put jacks (cranes) under it and weld it up and not let china have RF astronomy dominance.

C'mon ...  :palm:

Here an idea, why not turn the whole metal structures into bulk metal scraps, sell it to the Chinese to feed your fellow poor Puerto Ricans that have been abandoned by the current POTUS.  :-DD

Here, few more informational propaganda videos to enlighten you ...  >:D




Btw, she used Fluke DMM, at least something you can be proud of.  >:D

« Last Edit: November 21, 2020, 04:34:31 am by BravoV »
 

Offline coppercone2

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Re: The end of the line for the Arecibo radio telescope
« Reply #11 on: November 21, 2020, 05:01:45 am »
is that thing made of aluminum?

I wonder why they can't fix it with careful welding and epoxy (reinforce with a epoxied frame then weld it up after its more secure. You would think they could put jacks (cranes) under it and weld it up and not let china have RF astronomy dominance.

C'mon ...  :palm:

Here an idea, why not turn the whole metal structures into bulk metal scraps, sell it to the Chinese to feed your fellow poor Puerto Ricans that have been abandoned by the current POTUS.  :-DD

Here, few more informational propaganda videos to enlighten you ...  >:D




Btw, she used Fluke DMM, at least something you can be proud of.  >:D



yea if you climb up there you can stabilize the structure with a glue scaffolding before you start grinding it and dressing welds etc. It probobly got messed up when the line tore out and hundreds of tons started to shake. I expect lots of deformation, damaged bolts and some tearing. Not to mention it probobly draws lots of rich smart people with lots of disposable income to a country thats not doing so well. You don't really want (especially high power RF signals radar experts *cough* stealth detection *cough*) those people going to china. That thing did alot more for the world then just generating some data for the duration of its existence. CCP seti is more like search for 'capitalist objects of party interest'.
« Last Edit: November 21, 2020, 05:12:21 am by coppercone2 »
 

Offline magic

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Re: The end of the line for the Arecibo radio telescope
« Reply #12 on: November 21, 2020, 07:56:17 am »
It's the suspended antenna platform which is in danger of falling down if the remaining cable snaps. It weights a few hundred tons and hangs 150m above ground and still tens of meters above surrounding hills, so not that easy to give it additional support. And nobody has the balls to climb it and replace the failed cables. Not sure why they couldn't do it from a helicopter or something - maybe the cables are too heavy to lift from the ground without using the structure itself for support.

I wonder how they built it in the first place.
 

Offline coppercone2

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Re: The end of the line for the Arecibo radio telescope
« Reply #13 on: November 21, 2020, 05:18:06 pm »
given what they say about the rope slipping out, it sounds like a bad crimp job or bolts not being tightened. The rope should have been tied on the other side, I guess they tried to make it 'neat' and cut the remaining off after it was crimped into place. Then the knot should have wedged into the crimp as a secondary protection method.

I guess this is the way to do it, you don't really see knots on suspension bridges either. But those HAVE to be aesthetically pleasing. When I see a project of this magnitude fail by a 'slip' it really makes me wonder. I never liked rope suspensions, the interface between the solid and the rope always seemed suspect.
« Last Edit: November 21, 2020, 05:21:39 pm by coppercone2 »
 

Offline station240

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Re: The end of the line for the Arecibo radio telescope
« Reply #14 on: November 21, 2020, 06:04:51 pm »
It's the suspended antenna platform which is in danger of falling down if the remaining cable snaps. It weights a few hundred tons and hangs 150m above ground and still tens of meters above surrounding hills, so not that easy to give it additional support. And nobody has the balls to climb it and replace the failed cables. Not sure why they couldn't do it from a helicopter or something - maybe the cables are too heavy to lift from the ground without using the structure itself for support.

I wonder how they built it in the first place.

The suspended mass is 900 tons.
The main problem is any replacement cables cannot be installed without putting people onto the structure, or in the path of cables should they break.
ALL the cables have been found to be weaker than expected.

https://edition.cnn.com/2020/11/19/world/arecibo-telescope-decommission-damage-scn-trnd/index.html
"After the break on November 6, engineers inspected the rest of the cables and discovered new breaks as well as slippage from some of the sockets on the towers. Multiple engineering companies reviewed the damage. They determined that the telescope could collapse because it is "in danger of catastrophic failure" and the cables are weaker than expected."

"While no direct cause for the breaks has been identified, corrosion is suspected as the main issue. The observatory has withstood hurricanes, earthquakes and tropical storms over the years."

"Even if engineers could safely fix all the damage and add cables to support the telescope, it would likely have stability issues in the future."
 
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Offline David Hess

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Re: The end of the line for the Arecibo radio telescope
« Reply #15 on: November 21, 2020, 07:56:11 pm »
A search turns up various articles which discuss funding problems for Arecibo starting back in 2007 and funding being directed toward support programs instead of maintenance.
 

Offline bsfeechannel

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Re: The end of the line for the Arecibo radio telescope
« Reply #16 on: November 21, 2020, 08:40:58 pm »
That'll be a helluva skateboard bowl.
 
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Offline station240

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Re: The end of the line for the Arecibo radio telescope
« Reply #17 on: November 21, 2020, 11:28:40 pm »
Scott Manley video, about the problems with the dish, and also how it was constructed.
 
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Offline bsfeechannel

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Re: The end of the line for the Arecibo radio telescope
« Reply #18 on: November 26, 2020, 11:47:54 am »
Hello wonderful person! I knew Dave watches this guy, but now I know this guy watches Dave.



My sensors indicate the presence of an upcoming Amphour guest.
 

Offline cdev

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Re: The end of the line for the Arecibo radio telescope
« Reply #19 on: November 26, 2020, 04:29:23 pm »
Arecibo seems to me to be kind of a unique location and resource, but maybe the science of radio astronomy can achieve equivalent or higher resolution by using multiple smaller dishes and its more flexible. 

STILL, I'm always inclined to repair rather than replace. Or, why not replace the entire thing, that sounds like it mightbe cheaper than repairing, especially if they could automate as much as possible of it.

This seems like an engineering problem that is likely fixable with a little innovation. An ideal candidate for a contest, "How would you fix or replace the Arecibo Radio Telescope economically" or similar. The winner and their family or a friend can get three free trips to Arecibo, and a party to be held in the winner's honor after the successful repair, as well as the satisfaction of having helped.

I would guess that there must be an answer out there, and its probably not as complicated as they are making it out to be.

Isn't that the whole essence of science and engineering anyway?
« Last Edit: November 26, 2020, 04:38:23 pm by cdev »
"What the large print giveth, the small print taketh away."
 

Offline Bud

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Re: The end of the line for the Arecibo radio telescope
« Reply #20 on: November 26, 2020, 05:52:30 pm »
"It can't be repaired without dangers to the workers". Yes, by modern standards you can't fart when changing the bicycle wheel, as this puts you in danger.
We repair truss bridges in much more dangerous conditions, why this little structure can't be repaired .
Facebook-free life and Rigol-free shack.
 

Offline CatalinaWOW

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Re: The end of the line for the Arecibo radio telescope
« Reply #21 on: November 26, 2020, 05:57:29 pm »
As one of my mentors used to say "YAGOTTAWANNA"
 

Offline LaserSteve

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Re: The end of the line for the Arecibo radio telescope
« Reply #22 on: November 27, 2020, 12:48:57 am »
Maybe sell it to Elon?

Steve
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Offline Nauris

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Re: The end of the line for the Arecibo radio telescope
« Reply #23 on: November 27, 2020, 03:34:21 pm »
"It can't be repaired without dangers to the workers". Yes, by modern standards you can't fart when changing the bicycle wheel, as this puts you in danger.
We repair truss bridges in much more dangerous conditions, why this little structure can't be repaired .
If it did not come down on windy day, then I think it safe enought to climp on a calm day. Sounds more like of the ridiculous 'Safety First' corporate bullshit that big corporations are so full of.
They could just stabilize it with hundred small cables that are easier to handle than one big. One man with a winch on each end and third one sypplying cable from ground
 

Offline David Hess

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Re: The end of the line for the Arecibo radio telescope
« Reply #24 on: November 27, 2020, 03:42:03 pm »
If it did not come down on windy day, then I think it safe enought to climp on a calm day. Sounds more like of the ridiculous 'Safety First' corporate bullshit that big corporations are so full of.

Photographs show that the remaining cables have already had strands break due to excessive strain.  The structure could collapse at any time.

Quote
They could just stabilize it with hundred small cables that are easier to handle than one big. One man with a winch on each end and third one supplying cable from ground

It would take too much time, and cost too much considering available funds.
 


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