Author Topic: The end of the line for the Arecibo radio telescope  (Read 18371 times)

0 Members and 1 Guest are viewing this topic.

Offline Alex Eisenhut

  • Super Contributor
  • ***
  • Posts: 3549
  • Country: ca
  • Place text here.
Re: The end of the line for the Arecibo radio telescope
« Reply #50 on: December 01, 2020, 05:02:42 pm »
Aw crap.
Hoarder of 8-bit Commodore relics and 1960s Tektronix 500-series stuff. Unconventional interior decorator.
 

Offline CJay

  • Super Contributor
  • ***
  • Posts: 4136
  • Country: gb
Re: The end of the line for the Arecibo radio telescope
« Reply #51 on: December 01, 2020, 05:08:12 pm »
Awhh hell.

Now, do we clean it all up or leave it for a few dozen generations later to re-discover
 

Online coppercone2

  • Super Contributor
  • ***
  • Posts: 11336
  • Country: us
  • $
Re: The end of the line for the Arecibo radio telescope
« Reply #52 on: December 01, 2020, 05:13:54 pm »
drones were the only way it looks like this job could have been approached
 

Offline David Hess

  • Super Contributor
  • ***
  • Posts: 17427
  • Country: us
  • DavidH
Re: The end of the line for the Arecibo radio telescope
« Reply #53 on: December 01, 2020, 05:14:53 pm »
The structure could collapse at any time.

But why would it collapse at any time? I think it most probably comes down when there is some small extra stress acting on it like a gust of wind. So if it survived a windy day it is unlikely to come down following calm day and that is exactly the moment repair crew should be working on it.

https://www.sciencemag.org/news/2020/12/arecibo-telescope-collapses-ending-57-year-run
 

Offline LaserSteve

  • Super Contributor
  • ***
  • Posts: 1354
  • Country: us
Re: The end of the line for the Arecibo radio telescope
« Reply #54 on: December 01, 2020, 05:39:06 pm »
Aw Crap Squared...

Rebuild It!

How many other of our great infrastructure facilities are now ticking away at failure?

Steve
« Last Edit: December 01, 2020, 05:42:13 pm by LaserSteve »
"When in doubt, check the Byte order of the Communications Protocol, By Hand, On an Oscilloscope"

Quote from a co-inventor of the PLC, whom i had the honor of working with recently.
 

Offline CatalinaWOW

  • Super Contributor
  • ***
  • Posts: 5569
  • Country: us
Re: The end of the line for the Arecibo radio telescope
« Reply #55 on: December 01, 2020, 06:45:23 pm »
Now the questions are:
1. Is it too risky to go in and try to salvage any of the equipment?
2. Is there any way to stop locals from wildcatting this salvage?
 

Offline schmitt trigger

  • Super Contributor
  • ***
  • Posts: 2431
  • Country: mx
Re: The end of the line for the Arecibo radio telescope
« Reply #56 on: December 01, 2020, 07:32:01 pm »
Like some other poster mentioned, if the government had allocated only 0.1% of what has been spent on the Middle East wars, not only this would not have happened, additional facilities would have been built.
 

Offline SeanB

  • Super Contributor
  • ***
  • Posts: 16385
  • Country: za
Re: The end of the line for the Arecibo radio telescope
« Reply #57 on: December 01, 2020, 07:33:06 pm »
Now the questions are:
1. Is it too risky to go in and try to salvage any of the equipment?
2. Is there any way to stop locals from wildcatting this salvage?

Whatever was on the observing platform is now splashed all over, and not really salvageable, as it is likely all buckled from the impact, with only small parts likely to have survived. The rest is just scrap steel, so really heavy to move away, and thus not much will go missing.
 

Online coppercone2

  • Super Contributor
  • ***
  • Posts: 11336
  • Country: us
  • $
Re: The end of the line for the Arecibo radio telescope
« Reply #58 on: December 01, 2020, 07:41:26 pm »
lol give them the severance package the economy over there just got screwed
 

Offline TerraHertz

  • Super Contributor
  • ***
  • Posts: 3958
  • Country: au
  • Why shouldn't we question everything?
    • It's not really a Blog
Re: The end of the line for the Arecibo radio telescope
« Reply #59 on: December 02, 2020, 12:10:36 am »
 :'(
Grab some google maps 'as it was' aerial views before they get updated.
https://goo.gl/maps/RdVBXcomEEUDHiYd8

Before and after views by a local (700K):
Collecting old scopes, logic analyzers, and unfinished projects. http://everist.org
 

Offline David Hess

  • Super Contributor
  • ***
  • Posts: 17427
  • Country: us
  • DavidH
Re: The end of the line for the Arecibo radio telescope
« Reply #60 on: December 02, 2020, 03:21:04 am »
I was chatting with someone on IRC and they said that someone at Arecibo Tweeted that since the initial damage, they could hear strands of the cables breaking every few minutes.
 

Offline aseok

  • Contributor
  • Posts: 35
  • Country: de
Re: The end of the line for the Arecibo radio telescope
« Reply #61 on: December 02, 2020, 01:15:34 pm »
observatory collapsed on dish.
 

Offline jogri

  • Frequent Contributor
  • **
  • Posts: 405
  • Country: de
Re: The end of the line for the Arecibo radio telescope
« Reply #62 on: December 02, 2020, 02:02:24 pm »
Aw Crap Squared...

Rebuild It!

How many other of our great infrastructure facilities are now ticking away at failure?

Steve

Well, if you want to rebuild it you'd probably have to disassemble almost the entire dish and remove the towers with their foundations... The gregorian dome was assembled where the dish is now and then winched up, so you can't even save the remainder of the dish as you need the space to assemble the dome.

And call me a pessimist if you must, but imo almost all infrastructure suffers from a lack of maintenance: The budget is either too small from the beginning or the costs explode, so you have to "save money" somewhere-> you cut back on maintenance as it doesn't mean directly firing people (bad PR). And then you just give yourself a pat on the back for being a genius and blame others for not giving you money if it fails (hopefully when you are long gone and another sucker has your job).

I wouldn't be surprised if such occurences become the norm in a few years, quite a lot of the stuff that was build in the 60s and 70s is already starting to fail... Here in germany, nearly 15% of all highway bridges are classified as "dilapidated". And that is certainly not going to get better anytime soon.
 

Offline edy

  • Super Contributor
  • ***
  • Posts: 2387
  • Country: ca
    • DevHackMod Channel
Re: The end of the line for the Arecibo radio telescope
« Reply #63 on: December 02, 2020, 05:14:26 pm »


The death star suffered the same fate.... but not from lack of maintenance.
YouTube: www.devhackmod.com LBRY: https://lbry.tv/@winegaming:b Bandcamp Music Link
"Ye cannae change the laws of physics, captain" - Scotty
 

Offline tom66

  • Super Contributor
  • ***
  • Posts: 7334
  • Country: gb
  • Electronics Hobbyist & FPGA/Embedded Systems EE
Re: The end of the line for the Arecibo radio telescope
« Reply #64 on: December 02, 2020, 05:46:27 pm »
RIP.  Looks like they were right to not attempt to repair it, it was truly well past safe limits.

Rebuilding is surely the only option now but what is the likelihood of that?
 

Offline schmitt trigger

  • Super Contributor
  • ***
  • Posts: 2431
  • Country: mx
Re: The end of the line for the Arecibo radio telescope
« Reply #65 on: December 02, 2020, 07:56:16 pm »
One of the side effects of the Cold War was that “big science” projects, if they even provided the remotest opportunity of enhancing “the National Security”, whatever that meant, would be funded. Large scale funding, no buts or ifs.

Neither the USA nor Russia have the political will to commit to such projects nowadays.  In this instance the baton is solidly in China’s hands.

 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 13216
Re: The end of the line for the Arecibo radio telescope
« Reply #66 on: December 02, 2020, 08:40:23 pm »
Its worth looking at https://history.nasa.gov/SP-4218/ch4.htm which covers the earlier history of the Arecibo dish.

The only comparable dish for long range deep space radar is in southern China: https://en.wikipedia.org/wiki/Five-hundred-meter_Aperture_Spherical_Telescope
Its only been online since 2017 and wasn't fully operational till the beginning of this year.  We are lucky not to have had a critical gap in Earth's planetary radar capabilty.

Can the Western world really afford to leave accurate orbit characterization of Earth crossing asteroid threats to the Chinese?   There aren't that many near equatorial suitable sites in countries that are firmly under Western world control, so IMHO rebuilding at Arecebo is well worth considering - its already got most of the ancillary infrastructure required and a prepared depression that just needs the scrap cleared out.

The dish was originally wire mesh (literally chicken wire) and was upgraded to aluminum panels in the early '70s to extend its capability to S band operation.  A wire mesh dish (or partially wire mesh with a high quality aluminum reflector in the center, elongated on its north-south axis) might be a cheap way of getting reasonable capability back into operation on the site.   Its possible that significant areas of the reflector panels could be salvaged safely for reuse.

The Arecibo feed platform needed to be as massive as it was because it was built with 1960's technology.    Modern composites would permit a much lighter structure, and modern electronics would permit a significantly smaller structure, so it could reasonably be lowered onto composite pylons protruding through the reflector to 'dock' it for maintenance and to withstand hurricanes.  Initially it could be lofted by a commercially available tower crane with its base located in the eastern or western quadrants of the reflector.  As funds allow, it could be upgraded to a suspension system similar to the previous one, but built with corrosion resistant materials.
« Last Edit: December 02, 2020, 08:45:50 pm by Ian.M »
 

Offline David Hess

  • Super Contributor
  • ***
  • Posts: 17427
  • Country: us
  • DavidH
Re: The end of the line for the Arecibo radio telescope
« Reply #67 on: December 02, 2020, 10:07:06 pm »
The only comparable dish for long range deep space radar is in southern China: https://en.wikipedia.org/wiki/Five-hundred-meter_Aperture_Spherical_Telescope
Its only been online since 2017 and wasn't fully operational till the beginning of this year.  We are lucky not to have had a critical gap in Earth's planetary radar capabilty.

The Chinese dish lacks radar capability.  The article you linked even says so and I have heard the same from other sources:

Fifth, Arecibo's larger secondary platform also housed several transmitters, making it one of only two instruments in the world capable of radar astronomy.
 

Offline Ian.M

  • Super Contributor
  • ***
  • Posts: 13216
Re: The end of the line for the Arecibo radio telescope
« Reply #68 on: December 02, 2020, 10:16:24 pm »
Thanks, David.

For effective radar, it isn't essential to transmit from the same antenna - one can use a phased array of much smaller remote dishes to form the transmit beam.  The downside is more wasted power and bigger side-lobes.  OTOH you *DO* need real dish surface area to improve the signal to noise ratio of the radar receiver. 

Whether or not that capability could easily and quickly be added to FAST would depend on what high bandwidth comms links they have to sync large steerable transmit capable dishes in the region.   Before Arecibo's failure there wasn't a great incentive to do so.

However I really shouldn't complain about your correction as it makes the case for an improved Arecibo rebuild with a fully movable feed platform (at least on a North/South axis) even stronger.
« Last Edit: December 02, 2020, 10:25:54 pm by Ian.M »
 

Offline David Hess

  • Super Contributor
  • ***
  • Posts: 17427
  • Country: us
  • DavidH
Re: The end of the line for the Arecibo radio telescope
« Reply #69 on: December 02, 2020, 10:49:14 pm »
For effective radar, it isn't essential to transmit from the same antenna - one can use a phased array of much smaller remote dishes to form the transmit beam.  The downside is more wasted power and bigger side-lobes. 

You could have just said "bistatic radar".  :)

https://en.wikipedia.org/wiki/Bistatic_radar

Quote
OTOH you *DO* need real dish surface area to improve the signal to noise ratio of the radar receiver.

The antenna aperture is just as important on transmit as receive.  If they had suitable transmitting dishes with enough aperture, then they would not need the larger dish.  I suspect in the case of radar it is more cost effective to use a larger dish with one large transmitter than to replicate the transmitters for many separate dishes.

Quote
Whether or not that capability could easily and quickly be added to FAST would depend on what high bandwidth comms links they have to sync large steerable transmit capable dishes in the region.   Before Arecibo's failure there wasn't a great incentive to do so.

However I really shouldn't complain about your correction as it makes the case for an improved Arecibo rebuild with a fully movable feed platform (at least on a North/South axis) even stronger.

Or China will add that capability to their dish, although I get the feeling after reading various discussions that that will not be easy because it was not designed for it.
 

Offline jmelson

  • Super Contributor
  • ***
  • Posts: 2851
  • Country: us
Re: The end of the line for the Arecibo radio telescope
« Reply #70 on: December 03, 2020, 02:18:10 am »

I wouldn't be surprised if such occurences become the norm in a few years, quite a lot of the stuff that was build in the 60s and 70s is already starting to fail... Here in germany, nearly 15% of all highway bridges are classified as "dilapidated". And that is certainly not going to get better anytime soon.
It has actually been going on for quite some time.  I work in the basic nuclear science area.  When I got started, there were ion accelerators all over the place.  Now, a whole bunch of them have been shut down, or available only to commercial customers, etc.  So, the old cyclotron at Oak Ridge national lab was shut down, then the Van de Graff there was shut down (highest voltage Van de Graff in the world, 50 MV), the 88" cyclotron at Lawrence Berkeley Labs was made only available to cash customers, right now the superconducting cyclotrons at MSU are being shut down and scrapped.  A bunch of other facilities have also been shut down.  All due to a VASTLY shrinking science budget in the US.

Jon
 

Offline 0culus

  • Super Contributor
  • ***
  • Posts: 3032
  • Country: us
  • Electronics, RF, and TEA Hobbyist
Re: The end of the line for the Arecibo radio telescope
« Reply #71 on: December 03, 2020, 03:08:58 am »
Well, at least its now covered by -> FAST and bigger, comparison of Arecibo's size vs FAST.




The thing is Arecibo was also a radar....FAST to my knowledge is a receiver only.
 

Offline BravoV

  • Super Contributor
  • ***
  • Posts: 7549
  • Country: 00
  • +++ ATH1
Re: The end of the line for the Arecibo radio telescope
« Reply #72 on: December 03, 2020, 03:10:27 am »
All due to a VASTLY shrinking science budget in the US.

The Chinese FAST dish cost US$171 millions (excl.data processing center) (-> Reference), for US, say mark it up 3 times as more expensive labour, more advanced design and technology, and prolly corruption too  :P, say at a half billion US$, this figure still like a drop of water in the lake compared to military budget.

Offline BravoV

  • Super Contributor
  • ***
  • Posts: 7549
  • Country: 00
  • +++ ATH1
Re: The end of the line for the Arecibo radio telescope
« Reply #73 on: December 03, 2020, 03:33:05 am »
Can this FAST morpheable dish have advantage if used for radar ?





« Last Edit: December 03, 2020, 03:49:16 am by BravoV »
 

Offline BravoV

  • Super Contributor
  • ***
  • Posts: 7549
  • Country: 00
  • +++ ATH1
Re: The end of the line for the Arecibo radio telescope
« Reply #74 on: December 03, 2020, 03:59:28 am »
The thing is Arecibo was also a radar....FAST to my knowledge is a receiver only.

Just guessing, when in design stage, someone there or an entity (military maybe ?) should have thought of this ?  :-//


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf