The observatory has recently fallen on harder times though, leading to the NSF’s announcement Thursday that the facility would be officially decommissioned. While scarce funding over the last decade was likely a contributing factor, what ultimately did the observatory in was a series of failures of its critical physical infrastructure.
Arecibo’s main dish is fixed into the ground, with the radio waves that it reflects being intercepted by an instrument platform suspended above the dish. That platform is held aloft by cables attached to three towers on the rim of the dish. In August of this year, however, one of the auxiliary cables snapped and left a gash in the dish when it fell. Repair plans were being formulated when another cable, one of the main ones this time, also snapped on Nov. 6. At that point, an engineering analysis was conducted and determined that the stability of the entire platform was questionable and that it would be too risky to send repair crews out onto it.
“Until these assessments came in, our question was not if the observatory should be repaired but how,” said Ralph Gaume from the NSF. “But in the end, a preponderance of data showed that we simply could not do this safely. And that is a line we cannot cross.”
