Author Topic: Arecibo Observatory dish suffers serious damage (failed suspension cable)  (Read 4872 times)

Brad Johnson

  • friend
  • Senior Member
  • ***
  • Posts: 18,030
  • Witty, charming, handsome, and completely insane.
Cable failure at the Arecibo Observatory. Punched a 100 ft wide hole in the dish.

https://www.space.com/arecibo-observatory-damaged-shut-down.html

https://www.youtube.com/watch?v=4V3VCt24tkE

Not something you want happening to one of the most used radio telescopes in the world. I tried to find something referencing how long the wait is for scheduling research time but didn't see anything.

Brad
It's all about the pancakes, people.
"And he thought cops wouldn't chase... a STOLEN DONUT TRUCK???? That would be like Willie Nelson ignoring a pickup full of weed."
-HankB

Fly320s

  • friend
  • Senior Member
  • ***
  • Posts: 14,415
  • Formerly, Arthur, King of the Britons
I bet it was.... Aliens.
Islamic sex dolls.  Do they blow themselves up?

Brad Johnson

  • friend
  • Senior Member
  • ***
  • Posts: 18,030
  • Witty, charming, handsome, and completely insane.
It's all about the pancakes, people.
"And he thought cops wouldn't chase... a STOLEN DONUT TRUCK???? That would be like Willie Nelson ignoring a pickup full of weed."
-HankB

WLJ

  • friends
  • Senior Member
  • ***
  • Posts: 27,847
  • On Patrol In The Epsilon Eridani System
The Arecibo Observatory did not kill itself
"Sometimes I think the surest sign that intelligent life exists elsewhere in the universe is that none of it has tried to contact us".
- Calvin and Hobbes

K Frame

  • friend
  • Senior Member
  • ***
  • Posts: 44,009
  • I Am Inimical
Trump, obviously.
Carbon Monoxide, sucking the life out of idiots, 'tards, and fools since man tamed fire.

Jim147

  • friends
  • Senior Member
  • ***
  • Posts: 7,587
Best way to prep for invasion.

Who had Alians on their 2020 bingo card?
Sometimes we carry more weight then we owe.
And sometimes goes on and on and on.

BAH-WEEP-GRAAAGHNAH WHEEP NI-NI BONG

French G.

  • friend
  • Senior Member
  • ***
  • Posts: 10,184
  • ohhh sparkles!
Trump, obviously.

Maybe Obama. I know his admin chopped funding for green bank telescope while sending National Science Foundation grant money to an observatory in South America.
AKA Navy Joe   

I'm so contrarian that I didn't respond to the thread.

Ben

  • Administrator
  • Senior Member
  • *****
  • Posts: 45,742
  • I'm an Extremist!
"I'm a foolish old man that has been drawn into a wild goose chase by a harpy in trousers and a nincompoop."

K Frame

  • friend
  • Senior Member
  • ***
  • Posts: 44,009
  • I Am Inimical
Friend of mine used to be the public information officer for NRAO. He was not amused with the funding drop to Green Bank.

Of course, since we were in college together he's gone from passively liberal to flaming communist, so he would have been unamused had Trump increased funding to Green Bank.
Carbon Monoxide, sucking the life out of idiots, 'tards, and fools since man tamed fire.

230RN

  • It's like swimming to shore in an ebb tide.
  • friend
  • Senior Member
  • ***
  • Posts: 18,826
  • Pushing back. Help me out, here...
Scott Manley's video was great, thanks Brad.

https://www.youtube.com/watch?v=4V3VCt24tkE

Very interesting that the main reflector is spherical so they can "look around," and the corrections to parabolic equivalency are made with secondary mirrors in the observation capsule.  Sort of like compound lenses in camera lenses with spherical and chromatic etc aberration corrections. Wow on the math !

I still wonder how come a regular mirror reverses things left and right but not up and down. =D

I had to laugh a bit at 8:16.  My only thought was "Big brother is watching you."

Terry, 230RN

Edited to add big grin just because.

Screen capture at the aforesaid 8:16, looking up at the observation capsule:
« Last Edit: August 14, 2020, 08:15:49 AM by 230RN »

K Frame

  • friend
  • Senior Member
  • ***
  • Posts: 44,009
  • I Am Inimical
"I still wonder how come a regular mirror reverses things left and right but not up and down."

I asked a teacher that in elementary school...

I was told I was disrupting class.

I later figured out that was teacher speak for "Don't make me look stupid in front of a roomful of 9 year olds you little bastard!"
Carbon Monoxide, sucking the life out of idiots, 'tards, and fools since man tamed fire.

MechAg94

  • friend
  • Senior Member
  • ***
  • Posts: 33,622
"I still wonder how come a regular mirror reverses things left and right but not up and down."

I asked a teacher that in elementary school...

I was told I was disrupting class.

I later figured out that was teacher speak for "Don't make me look stupid in front of a roomful of 9 year olds you little bastard!"
Maybe if you laid down on your side it would work.   =D

I guess she wasn't the geometry teacher.  
“It is much more important to kill bad bills than to pass good ones.”  ― Calvin Coolidge

Brad Johnson

  • friend
  • Senior Member
  • ***
  • Posts: 18,030
  • Witty, charming, handsome, and completely insane.

I still wonder how come a regular mirror reverses things left and right but not up and down. =D


How about a non-reversing mirror?

https://youtu.be/x2owiSx0biU

Brad
It's all about the pancakes, people.
"And he thought cops wouldn't chase... a STOLEN DONUT TRUCK???? That would be like Willie Nelson ignoring a pickup full of weed."
-HankB

230RN

  • It's like swimming to shore in an ebb tide.
  • friend
  • Senior Member
  • ***
  • Posts: 18,826
  • Pushing back. Help me out, here...
Boy, am I glad I went back and added that biggrin emoticon. =D.

Hawkmoon

  • friend
  • Senior Member
  • ***
  • Posts: 27,197
How about a non-reversing mirror?

https://youtu.be/x2owiSx0biU


That voice is hyper annoying.
- - - - - - - - - - - - -
100% Politically Incorrect by Design

230RN

  • It's like swimming to shore in an ebb tide.
  • friend
  • Senior Member
  • ***
  • Posts: 18,826
  • Pushing back. Help me out, here...
.ti teg t'nod llits I







(Backwards text generator for your amusement:

https://www.prepostseo.com/tool/reverse-text-generator
)

Brad Johnson

  • friend
  • Senior Member
  • ***
  • Posts: 18,030
  • Witty, charming, handsome, and completely insane.
Re: Arecibo Observatory dish suffers serious damage (failed suspension cable)
« Reply #16 on: November 19, 2020, 03:51:55 PM »
Stick a fork in it. NSF announced today that extensive damage and dangers associated with repairs combine to form an insurmountable hurdle. The Arecibo Observatory is to be decommissioned in its entirety.

https://www.space.com/arecibo-observatory-radio-telescope-to-be-destroyed?fbclid=IwAR3_1MWNP9vNIJi-QsD8xBz_zOPrxaAsSsu-KiYDds2mkkwviW9-uhg-1Lc

It's a rather undignified end to a long and lustrous career, but the memories are warm and the contributions many.

Brad
It's all about the pancakes, people.
"And he thought cops wouldn't chase... a STOLEN DONUT TRUCK???? That would be like Willie Nelson ignoring a pickup full of weed."
-HankB

MillCreek

  • Skippy The Wonder Dog
  • friend
  • Senior Member
  • ***
  • Posts: 19,963
  • APS Risk Manager
Re: Arecibo Observatory dish suffers serious damage (failed suspension cable)
« Reply #17 on: November 19, 2020, 04:39:45 PM »
^^^Is there anything to replace it? The VLA in New Mexico?
_____________
Regards,
MillCreek
Snohomish County, WA  USA


Quote from: Angel Eyes on August 09, 2018, 01:56:15 AM
You are one lousy risk manager.

lee n. field

  • friend
  • Senior Member
  • ***
  • Posts: 13,534
  • tinpot megalomaniac, Paulbot, hardware goon
Re: Arecibo Observatory dish suffers serious damage (failed suspension cable)
« Reply #18 on: November 19, 2020, 06:11:56 PM »
I bet it was.... Aliens.

Yeah, my thought.  Getting ready to sneak in under the radar, so to speak.

Best way to prep for invasion.

Who had Alians on their 2020 bingo card?

Duh.  Ev-ery-body.
In thy presence is fulness of joy.
At thy right hand pleasures for evermore.

Hawkmoon

  • friend
  • Senior Member
  • ***
  • Posts: 27,197
Re: Arecibo Observatory dish suffers serious damage (failed suspension cable)
« Reply #19 on: November 19, 2020, 06:30:56 PM »
Stick a fork in it. NSF announced today that extensive damage and dangers associated with repairs combine to form an insurmountable hurdle. The Arecibo Observatory is to be decommissioned in its entirety.

https://www.space.com/arecibo-observatory-radio-telescope-to-be-destroyed?fbclid=IwAR3_1MWNP9vNIJi-QsD8xBz_zOPrxaAsSsu-KiYDds2mkkwviW9-uhg-1Lc

It's a rather undignified end to a long and lustrous career, but the memories are warm and the contributions many.


Good grief!

Quote
"It is, I think, just truly unfortunate that this main cable failed before we had a chance to get things stabilized," Zauderer said.

Obviously, it would have been much better if they had gotten it stabilized, and then the main cable failed. Then they could start all over with trying to re-stablize it.

What's puzzling to me is the statement that they (the engineers hired to study the problem) don't know what the factors of safety are. I'm an architect, not a structural engineer, but structural engineering is part of the education for architects and, in theory, I am legally allowed to practice engineering when it's ancillary to an architectural design I create. Basically, even for structures such as this that don't slot neatly into building codes with their safety factor requirements, It has been my understanding through fifty years of practice that everything a structural engineer does has established factors of safety. What this suggests to me is that some or all of the original design computations must have been lost, discarded, or destroyed, so the teams reviewing the structure now can't reproduce the calculations to decide what's safe and what's not.
- - - - - - - - - - - - -
100% Politically Incorrect by Design

K Frame

  • friend
  • Senior Member
  • ***
  • Posts: 44,009
  • I Am Inimical
Re: Arecibo Observatory dish suffers serious damage (failed suspension cable)
« Reply #20 on: November 20, 2020, 12:05:08 PM »
The one article says that the science platform in the center is... 9 HUNDRED tons?

Holy *expletive deleted*it.
Carbon Monoxide, sucking the life out of idiots, 'tards, and fools since man tamed fire.

Brad Johnson

  • friend
  • Senior Member
  • ***
  • Posts: 18,030
  • Witty, charming, handsome, and completely insane.
Re: Arecibo Observatory dish suffers serious damage (failed suspension cable)
« Reply #21 on: November 20, 2020, 12:30:09 PM »
The one article says that the science platform in the center is... 9 HUNDRED tons?

Holy *expletive deleted*it.

Just a guess, but I figure it was made intentionally heavy for dimensional stability reasons. When you're peering a couple billion light years into the universe, a twitchy instrument platform can kinda be a thing.

Brad
It's all about the pancakes, people.
"And he thought cops wouldn't chase... a STOLEN DONUT TRUCK???? That would be like Willie Nelson ignoring a pickup full of weed."
-HankB

K Frame

  • friend
  • Senior Member
  • ***
  • Posts: 44,009
  • I Am Inimical
Re: Arecibo Observatory dish suffers serious damage (failed suspension cable)
« Reply #22 on: November 20, 2020, 02:13:41 PM »
Good point. I hadn't though of that.

But, I bet when it starts oscillating it takes a LONG time to settle down.
Carbon Monoxide, sucking the life out of idiots, 'tards, and fools since man tamed fire.

230RN

  • It's like swimming to shore in an ebb tide.
  • friend
  • Senior Member
  • ***
  • Posts: 18,826
  • Pushing back. Help me out, here...
Re: Arecibo Observatory dish suffers serious damage (failed suspension cable)
« Reply #23 on: November 21, 2020, 11:30:00 AM »
I'm wondering if what they mean is, that's the total tension required on the cables or something like that.

When one refers to a tightrope walker, that rope has to be really, really tight.

  
 

I've forgotten how to do the calculations (high school, ~1955), but I know that even a small weight on a "tight" "rope" will deflect the rope substantially no matter how "tight" the rope is.

So it seems to me that large number (900 tons) might refer to the suspension cable tensions rather than the weight of the module.

Hawkmoon, what do  you think?

Terry, 230RN

Pic credits in properties.  The tightrope walker may not be an actual image.

« Last Edit: November 21, 2020, 01:27:16 PM by 230RN »

K Frame

  • friend
  • Senior Member
  • ***
  • Posts: 44,009
  • I Am Inimical
Re: Arecibo Observatory dish suffers serious damage (failed suspension cable)
« Reply #24 on: November 21, 2020, 12:02:20 PM »
"When you're peering a couple billion light years into the universe, a twitchy instrument platform can kinda be a thing."

Except, it's a radio telescope, so stability isn't really that critical, I don't think.

I know the big optical telescopes are generally mounted on temperature-controlled floors, often held at freezing, to keep the floor from expanding and contracting and moving the scope. My astronomy professor at college broke his ankle at one of the optical telescopes when he slipped on ice on the floor, even though it was summer out.
Carbon Monoxide, sucking the life out of idiots, 'tards, and fools since man tamed fire.