Eulogy To Arecibo: With Demise Of A Unique Scientific Facility, Who Will Carry The Torch?

Few telescopes will get an emotional response from the general public when it is ultimately announced that they will be decommissioned. In the case of the Arecibo Observatory in Arecibo, Puerto Rico, the past months has seen not only astronomers but also countless people across the world wait with bated breath after initial reports of damage to the radio telescope’s gigantic dish.

When the National Science Foundation announced that they would be decommissioning the telescope, there was an understandable outpouring of grief and shock. Not only is Arecibo a landmark in Puerto Rico, it is the telescope from iconic movies such as GoldenEye (1995) and Contact (1997). Its data fed public programs such as the Seti@Home and Einstein@Home projects.

Was Arecibo’s demise truly unavoidable, and what does this mean for the scientific community?

What Defines Arecibo

The Green Bank Telescope.

The real question is, what have we lost? Are there successors to Arecibo that are able to fill the very large gap now facing the scientific community? Looking at the aspects of the telescope that made it unique helps us find those answers.

Telescopes are essentially highly sensitive instruments for observing remote sources of electromagnetic radiation. In the case of optical telescopes, this means the visible part of the EM spectrum. Radio telescopes work in a similar way but are tuned to receive radio frequencies. Arecibo was capable of capturing between 1-10 GHz with multiple receivers using an effective 221 meters of its 304 meter diameter. Much like how an optical telescope’s primary mirror largely determines how much light will ultimately reach the sensor, so too does the size and shape of a radio telescope’s primary mirror (dish).

Most telescopes can be adjusted to point the reflector at different parts of the sky. This is mostly a matter of what mechanics and engineering allow, with the Green Bank Telescope in West Virginia currently the largest fully steerable radio telescope with a dish diameter of 100 meters. Puerto Rico’s Arecibo and China’s FAST radio telescope have fixed reflectors that make use of natural depressions in the terrain left by a karst sinkhole. Within this bowl-shaped depression the elements that make up the dish are installed, largely following those contours, with a moveable receiver array to aim the telescope. While convenient, this limits the view of these telescopes to a fairly narrow part of the sky.

The illuminated area of the FAST telescope on the primary dish.

Both newer and physically larger, it would seem obvious that China’s FAST telescope is superior to Arecibo, this is not entirely true. Arecibo’s dish reflectors are mounted in place more rigidly than FAST’s. While the latter is more flexible with winches able to adjust the shape of the reflector mesh, this comes with trade-offs at these higher frequencies. Even with upgrades to FAST’s receivers similar to the upgrades which Arecibo received in 1997, FAST would only be able to cover frequencies up to about 5 GHz, only half of Arecibo’s performance.

In addition to these properties, there is also the question of radar astronomy, which requires the transmission of powerful radar signals. Arecibo has four radar transmitters, of 20 TW (continuous), 2.5 TW (pulsed), 300 MW and 6 MW. These take up a significant amount of space, and therefore cannot be mounted in FAST’s secondary platform alongside its receivers due to weight and space concerns. Arecibo is only one of two telescopes that have seen regular use in radar astronomy, the other being the 70 meter Goldstone Solar System Radar, with a 500 kW transmitter.

With the detection of asteroids and comets being an essential part of Arecibo’s radar astronomy duties (tracking & early warning system), this has left a major blind spot. Without Arecibo, we have to mostly rely on optical telescopes to track these objects as they hurtle through the solar system.

The Infrastructure Budget Dance

Perhaps not surprisingly, Arecibo is a Cold War artifact, envisioned as part of an anti-ballistic missile (ABM) shield. Installations like Arecibo would provide detection duties, being presumably sensitive enough to filter out the real warheads from the fake ones within a MIRV ICBM from their radar signature. Without a solid understanding of the exact physics of a re-entering ICBM, Arecibo was part of an ARPA-led effort to fill in the knowledge gaps here.

As the Cold War dragged on and priorities shifted before the final dissolution of the Soviet Union, Arecibo saw itself placed in a situation not dissimilar to the rust and flaking paint-covered marvels of the Soviet Union. Unneeded as a military asset, it saw its operational budget reduced year over year. Even with asteroid research as one of its unique mission profiles, in 2001 NASA announced that they would cut funding by 27% and ‘encouraged’ the National Science Foundation (NSF) to fund the $11 million budget of the whole program.

In 2007, the NSF announced that due to their own budget being reduced, they would have to close Arecibo unless other sources of funding could be found. Of note here is that Puerto Rico itself is rather poor, with its government not having the financial means to support even such an iconic telescope, and no senators in Washington DC to lobby on its behalf due to Puerto Rico not being a US state.

NASA funding for the telescope was restored in 2010, with an increase in 2012 to $3.5M/year. Despite this, the NSF made changes to the way Arecibo Observatory was run during this period, seeking commercial and other partners and removing Cornell University from the project. By 2015, the NSF was signalling that it was looking at decommissioning the facility.

When hurricane Maria damaged the 430 MHz feed line and part of the primary dish in 2017, a consortium led by the University of Central Florida (UCF) managed to stave off the observatory’s decommissioning through financial support, but then on August 10th, 2020, one of the secondary platform support cables broke, damaging the primary dish and the receiver platform.

As the decades of limping on with a minimal operating budget caught up with reality, November 7th saw a second cable snap, further damaging the primary dish. After engineers examined the facility following this second accident the statement to the press said that:

Preliminary analysis indicates the main cable, which failed on November 6, should have easily handled the extra load based on design capacity. Engineers suspect it is likely that the second cable failed because it has degraded over time and has been carrying extra load since August.

All of this seems to point towards the lack of a maintenance budget leading to the situation where the many cables of the Arecibo Observatory were not regularly inspected, maintained, or replaced. Especially in a fairly humid and warm climate like that of Puerto Rico where the corrosion of steel cables would be accelerated, a lack of maintenance would have caused reductions in carrying capacity.

What Could Have Been

Arecibo Observatory from the air in happier days.

A major problem with scientific installations like Arecibo is that they are not flashy or cool enough to warrant a constant flow of funding, with some Administrations worse than others. The main reason is that a lot of science involves mostly waiting, digging through years worth of data, more waiting and crunching more numbers and running models in the hope that you see a theorem confirmed.

When a politician or the average person on the street is asked what their thoughts on Arecibo’s demise are, it’s unlikely that many could sum up what the facility was used for, and why its loss is felt far beyond the astronomy community.

The Ángel Ramos Foundation Visitor Center located near the observatory was opened in 1997. It serves as an educational center with exhibits and displays not only about the Arecibo Observatory, but also astronomy and the atmospheric sciences. With the loss of the observatory the future of this center and the role of Puerto Rico in astronomy is put very much into doubt.

For the Future

In a world where some individuals count their worth in billions and Wall Street marks its progress in trillions, the operation and maintenance budget for a facility such as Arecibo is microscopically small. Despite that, there seems to be no indication that the decision to decommission Arecibo will be reverted. Whether or not a replacement facility will be built in Puerto Rico or anywhere in the US is still left up in the air at this point.

All that we know for certain right now is that despite its different geographical location and lack of radar transmitting capacity, the FAST telescope along with a host of smaller radio telescopes will be able to pick up most of the slack there. Due to China’s treatment of large scientific projects as a sign of prestige, in addition to building FAST, they are also scheduled to bring the country’s fully steerable 110 meter Qitai Radio Telescope online in 2023, which would make it the largest of its kind in the world.

One can only hope that the US and others take the bait and begin a friendly competition with China on building the best, most useful telescopes and other scientific projects to further humankind’s reach to the stars. Because in the end, having only crumbling sites like Arecibo to show for one’s economic prowess isn’t worth much at all when that one large asteroid manages to not avoid Earth.

50 thoughts on “Eulogy To Arecibo: With Demise Of A Unique Scientific Facility, Who Will Carry The Torch?

  1. Maya, thanks for that budget and funding chronology for Aricebo. This is invaluable in showing the erosion and decline as management shifted between organizations and Presidential administrations. Even with the end of the Cold War we never saw that kind of decline in Dept. of Energy (nuclear stockpile stewardship for example). Just wish we could have kept it going a little longer. Maybe an Elon Musk will come along and save us all.

      1. Looks like the numbers came from Wikipedia, which came from a PDF from Arecibo. That PDF describes the transmitter power as 2.5MW pulsed or 150kW average. The terawatt numbers are EIRP values. I had to look that up. Effective isotropic radiated power, apparently compares the very directional transmitter power that dish antennas like Arecibo have to what a hypothetical omnidirectional antenna would need to match it. So it’s a calculated value and not an actual power output value.

        1. The Free Space Path Loss would use the EIRP. The distance propagated, in that direction, would be based on the 20 TW (~133dBm) @ 2.38 GHz or 2.5 TW (~123.78 dBm) @ 2.38 GHz and not on input power to the antenna.

    1. There are 2 words missing in the article: ‘equivalent’ and ‘omnidirectional’.

      From the SETI website:
      “The broadcast was particularly powerful because it used Arecibo’s megawatt transmitter attached to its 305 meter antenna. The latter concentrates the transmitter energy by beaming it into a very small patch of sky. The emission was equivalent to a 20 trillion watt omnidirectional broadcast, and would be detectable by a SETI experiment just about anywhere in the galaxy, assuming a receiving antenna similar in size to Arecibo’s.”

    2. Speculation on my part. Effective Radiated Power;perhaps? All directed to a small part of space. The EME {moon bounce) arrays of many hams, have impressive ERP, directed towds a particular location.

      1. Yes, and while unique and leaving a hole, I expect that other ways to obtain the information will be found. These stories are “we’re all going to die” until we don’t. That’s the problem with all science reporting, it never allows for human innovation.

        1. Literally the only way to obtain the information is with something of equal or larger size. Big freaking interferometers (like the VLA and its equivalents) give equal resolution, but worse sensitivity – even if the total area of N receivers (N*A) is bigger than Arecibo, the sensitivity’s worse (by sqrt(N)) because of the independent noise.

          There’s no magic innovation that can help here, it’s really, really simple physics. If you want something with equivalent capabilities as Arecibo, it needs to be the same size or bigger than Arecibo.

      1. Did you bother to read Dish’s comment and my reply? The article refers to multiple other sites and I carified that innovation might fill the gap. I’m betting they haven’t even analyzed all the data gathered, and when they start re-analyzing it that will take decades more and uncover things they missed.

    1. You should have a simple search. I have seen both. This is not a classified installation. The latest cable failure was of an original cable where it started breaking strands in the middle of the span, whereas the original break was an end break of one of the 1997 renforcement addition cables where it pulled out of a termination. The 2nd break happened under 60% of the rated load for the cable so all the assessments are in doubt now. YouTube can be your friend.

  2. No, no, no. Arecibo was never part of anti-missile defense.

    Arpa funded it for research, to study some aspects of the ionosphere, which might have later been used for anti-missile work.

    But arpa funded lots of pure researcy things

    It’s always been a radio telescope, unless you’re suggesting it was cover.

    It’s been funded for science for decades.

    Yes, military is willing to throw money at things, so if you fixate on “missile defense” then Arecibo could have faded away in the sixties. Instead, that funding created this major radio telescope, so science funding wasn’t needed to create it, and instead of scrapping it after the studies, it was used for science.

    Military spending may mean less money for science, but it was never meant to be funded by the military on an ongoing basis, since it wasn’t a military installation.

  3. It enrages me the casual nature with which my government continously defends science and major scientific progress, yet funds the military without question to any ridiculous sum, and meanwhile the Chinese are actually investing in scientific projects, but much of their use of technology is in oppressing their own people and populations with the ultimate surveillance society.

    Too much of the world just doesn’t see science as something of value unless it can be used to attack or control others.

  4. A lot of people are focusing on the financial issues of this story, and that’s definitely why it got this bad, but the issue now is of safety. Even if Elon Musk decided to invest $500M tomorrow the best call at this point would be to decommission the telescope.

    They had 5 engineering teams inspect the facility after the second cable broke. According to an article in Science Magazine “If one of three remaining main cables connected to the impaired tower also failed, the engineers concluded, the platform would collapse” This thing is ONE broken cable away from collapsing and those existing cables are the same as the one that just unexpectedly failed. You couldn’t pay me to go work on that thing in the state it’s in an no one else should either.

    It’s a huge shame that the telescope ever got this way but it’s too late to un-neglect it.

    1. Is it too crazy an idea to build a mast up to the platform to support from below to both stabilize the existing cable supported instrument platform and house new instrumentation? ie. Could the existing dish surface possibly be used with a repaired disk surface for more research or even other types of research?

      1. Who would you send to build it under a heavy, high, suspended load waiting to fall at random moment?

        The only way is to somehow hang the platform from flying crane helicopter, while three crews stand ready to severe the lines on supporting masts on the rim of the dish (provided the masts don’t fall after sudden radial tension relief), and then carry the platform safely to the ground.

        After that inspect and repair the platform on the ground, masts as well, procure new steel ropes and power lines, and reconstruct the hanging structure with them similarly to how it was originally built.

          1. And at least the assessment was valid. They said it couldn’t be fixed, and within a week or two, it did collapse. I really thought it would sit there until they brought in equipment to tear it down.

            Maybe it could have been saved if immediate work had been done months back, but decision making moves slowly.

  5. Looks like with manufactured goods, electronics, food, medicine and just about everything else we’re going to be getting our science from China now (look at Chang’e 5 bring back rocks from the moon.) Looks like we’re going to have to steal research from China now. How the world changes. Learn Chinese.

  6. SRI (Stanford Research out of California) was paid to maintain the Arecibo research instrument — obviously they stole the money for something else. Just like many other worthwhile projects, the grants were given to a more powerful US Senator.

    The Arecibo instrument is unique and irreplaceable — Yes it is an amazing telescope, but also an incredibly powerful radar that emits giant pulses that can carry across the galaxy — as it did when we sent the “we are here” message for SETI.

    The estimate of maintenance (when it actually gets spent on the Arecibo project) is $10 million per year. The James Webb telescope only is 13 years late and so far has cost $10 BILLION(!) without producing a single image — now that is a CONNECTED project.

    NSF — Change your mind and allocate the funds to repair and refurbish.

    1. Stanford Research is an electronics company. They make high-precision instrumentation. I assume they were paid to maintain the RF transmitter/receiver and DSP equipment, not to inspect the steel structure of the dish itself…

      1. I mean, I can’t imagine what could’ve caused accelerated failure of the physical dish itself. Maybe if there were some sort of increase in the rate of natural disasters in that area of the world or something?

  7. As I noted in comment section of one of the previous Arecibo articles, NSF has been trying to close the observatory for quite some time. The reasons behind it are a mystery to me, but don’t really seem budget related.

    After all, what is almost always omitted in conversation, is the steady growth of the agencies budget. Despite the wishes of the POTUS.

  8. Truly epic failure on a planet wide scale… Sad the greedy imbeciles in charge of all the countries of the world couldn’t take even one second from their constant stealing and lying to do something for mankind. Its to be expected with the absolute and utter trash in power all over the world.

  9. I predict this will featured in a future, Neil DeGasee Tyson lecture, as another example how the USA, is ignoring it’s sceintific Leeadership. The PRC, has been filling the leadership hole, leftopen by the US. The aricle reads like China has head start, on this. Meanwhile the radio telescope, is small potatoes, if compared to the human suffering created by the same storm.

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