The collapsed Arecibo radio telescope was originally built for ballistic missile defense research

The U.S. government’s massive radio telescope in Arecibo, Puerto Rico, the world’s second-largest such instrument, collapsed on its own, virtually destroyed it, but fortunately did not cause injuries. While the site, which was completed in 1963, is best known for its work in radio astronomy, most do not realize that it was originally built with the support of the U.S. military, in part to support research and development in ballistic missile defense. systems.

The National Science Foundation (NSF), the U.S. agency that currently owns the site, has confirmed that the telescope’s triangular instrument platform of about 900 tons fell to a depth of 400 meters on December 1, 2020. The dashboard was suspended above the vessel by a cable running from three towers, one of which was virtually skewed in two during the collapse. The other two mountains are also said to have been broken.

“The instrument platform of the 305-meter telescope at the Arecibo Observatory in Puerto Rico fell overnight. No injuries occurred,” reads a post on NSF’s official Twitter account on Dec. 1. “NSF is working with stakeholders to assess the situation. Our top priority is to maintain security. NSF will provide further details when they are confirmed.”

On November 19, NSF had already announced that it would decommission the site after an assessment that showed the structure was too dangerous to function or even attempt to repair it. Cable breaks in August and November have already damaged the vessel and significantly increased the risk of collapse.

It sounded like a hum. I knew exactly what it was, ”said Jonathan Friedman, who lives near the site and worked for 26 years as a senior research fellow. Associated Press. “I screamed. Personally, I wasn’t controlled … I have no word to express. It’s a very deep, awful feeling.”

Radio telescopes are primarily designed to collect radio waves from objects in space, or even in the upper reaches of the Earth’s atmosphere, for a variety of research purposes. They are capable of “mapping” objects, from galaxies to individual planets to asteroids “near” Earth, using these signals.

The site of Arecibo dates back to the 1950s, when Cornell University proposed the construction of the Department of Defense Advanced Research Project Agency (ARPA), now known as the Defense Advanced Research Project Agency (DARPA). The desire to understand the composition of the ionosphere and the impact it could have on objects in transit, including the return vehicles of ballistic missiles carrying nuclear warheads, was a key reason for its construction.

At the time, ARPA was responsible for a broad ballistic missile defense program known as Project Defender. Nuclear warheads were thought to create a separate signature when they returned to the atmosphere, allowing baits to be distinguished, as long as the signature could be quickly identified and categorized. Using the Arecibo telescope, the plan helped gather general yet valuable information about the ionosphere to support this endeavor. ARPA is also interested in using it for various radar experiments. The telescope can still serve as a general research tool.

Cornell physicist and astronomer William E. Gordon oversaw the design of the telescope, which originally simply consisted of a large reflective vessel. Large sinkholes in and around Arecibo made the area ideal for accommodating this huge instrument.

However, ARPA was concerned that the original plan would limit the value of the telescope because it had a fixed field of view. This led to further design studies and the construction of a suspended instrument platform with a steerable beam steering mechanism. Work on the site, originally called the Ionospheric Research Institute of the Ministry of Defense, began in 1960, and in 1963 work began, renamed the Arecibo Ionospheric Observatory. In 1973, upgrades were made to increase the maximum operating frequency of the telescope.

In 1997, a Gregorian reflector system was installed, which allowed for more focused focusing of incoming radio waves, as well as a stronger transmitter. All of this allowed the site to play a role as a planetary radar, including monitoring potential threats in space, such as incoming asteroids. The entire complex of the Arecibo Observatory eventually housed a laser imaging system facing the square and a visitor center.

Cornell University operated the site from 1963 to 2011 on behalf of NSF, with additional funding from NASA. During this time, the site has supported various scientific research efforts, including the Extraterrestrial Intelligence Search (SETI) project. The researchers made their first attempt to contact an extraterrestrial species in 1974. During the Cold War, the use of the site for military intelligence purposes was also considered, including the search for Soviet radar signals after they bounced off the surface of the Moon. The U.S. military conducted intelligence on similar indirect signals with fixed “Elephant Cage” antenna systems located around the world.

In addition, Arecibo ran a film career as the venue for the 1995 climate show of Pierce Brosnan’s James Bond and Sean Bean Alec Trevelyan. Golden eye. He was also featured in 1997 Contact, is a dramatic film based on the real SETI program. He appeared in the 1995 sci-fi horror film Species and one episode of the bullseye The X-Files, is. Video game developers have also used the site over the years.