While the underfunding and collapse of the observatory is a tragedy, I think it is perhaps less surprising in the context that much of the original political wi

While the underfunding and collapse of the observatory is a tragedy, I think it is perhaps less surprising in the context that much of the original political will behind the observatory was motivated by potential military applications, which became somewhat passé after the fall of the Soviet Union. This "dual use" origin is mentioned briefly in the article here, but expanded in more length in some other sources [1,2]: The origins of the observatory trace to late 1950s efforts to develop anti-ballistic missile (ABM) defenses as part of the newly formed United States Department of Defense (DoD) Advanced Research Projects Agency (ARPA) ABM umbrella-effort, Project Defender. [...] It was known that hot, high-speed objects caused ionization of the atmosphere that reflects radar waves, and it appeared that a warhead's signature would be different enough from decoys that a detector could pick out the warhead directly, or alternately, provide added information that would allow operators to focus a conventional tracking radar on the single return from the warhead. Although the concept appeared to offer a solution to the tracking problem, there was almost no information on either the physics of re-entry or a strong understanding of the normal composition of the upper layers of the ionosphere. ARPA began to address both simultaneously. To better understand the radar returns from a warhead, several radars were built on Kwajalein Atoll, while Arecibo started with the dual purpose of understanding the ionosphere's F-layer while also producing a general-purpose scientific radio observatory. Some folks here may also be familiar with the US project to locate Soviet radar installations via signals reflected off the moon (as discussed in Steve Blank's excellent Secret history of Silicon Valley [3]), and it seems that Arecibo participated in this as well [4]: The CIA employed a 150-foot dish antenna at Stanford University in Palo Alto, California to monitor Soviet radar signals reflected off the moon, while the National Security Agency used the Arecibo Ionospheric Observatory in Puerto Rico to intercept signals that had originally been transmitted from a Soviet Arctic Coast radar. [1] https://en.wikipedia.org/wiki/Arecibo_Telescope#Design_and_construction https://en.wikipedia.org/wiki/Arecibo_Telescope#Design_and_c... [2] https://www.thedrive.com/the-war-zone/37898/collapsed-arecibo-radio-telescope-was-first-built-for-ballistic-missile-defense-research https://www.thedrive.com/the-war-zone/37898/collapsed-arecib... [3] https://steveblank.com/secret-history/ https://steveblank.com/secret-history/ [4] https://nsarchive2.gwu.edu/NSAEBB/NSAEBB479/ https://nsarchive2.gwu.edu/NSAEBB/NSAEBB479/