From: University of Central Florida
Posted: Thursday, September 10, 2020
Today marks 30 days since the Arecibo Observatory went offline, because an auxiliary cable broke and damaged the dish and Gregorian dome.
While no cause has yet been determined, the AO leadership team is working closely with the National Science Foundation (NSF), which owns the facility, to implement a plan to first stabilize the critical structural elements of the facility and to initiate a full forensic investigation of the cause of the cable failure.
UCF manages the NSF-facility under a cooperative agreement with Universidad Ana G. Méndez and Yang Enterprises Inc.
What’s been done to date:
* a team from the observatory and UCF have been meeting with more than 40 experts in the area of suspension cable fabrication and installation, structural analysis and forensic investigation;
* an observatory engineering and safety team was formed;
* three firms -- WSP, Thornton Thomasetti, and Wiss, Janney, Elstner Associates Inc. (WJE) have been hired to help coordinate the investigation, analysis and repair planning;
* NASA’s Engineering and Safety Center, Kennedy Space Center ,and Pfeifer Wire are also assisting in the review of the structure;
* a detailed structural model of the current state of the entire telescope began August 17 and is expected to be completed within the next two weeks;
* daily inspections of the structure are being conducted ;
* the Gregorian dome was moved into its “stow/safe” position, typically used for hurricane events, and the safety pins have been installed since August 20;
* basic functional tests have been conducted on the receivers, and at this time it appears there was no damage to the electronics inside the Gregorian dome, but the S-band radar has not been tested;
* observatory and UCF leadership have been regularly updating the NSF and NASA and other stakeholders.
In order to determine the root cause of the cable failure, the portion of the failed cable and socket must be retrieved for forensic analysis and investigation. These components cannot be retrieved until a comprehensive safety analysis of the facility is complete. This will be followed by a safety plan for the personnel who will be doing the work on the towers and the platform.
And the safety plan can’t be completed without the structural analysis. Computer modeling will be used to create a structural analysis, which will aid in determining the cause of the cable failure and whether other areas of the telescope are at higher risk as a result of the break. This modeling will help frame the scope of repairs, along with costs and schedule. And that’s why the analysis is key to the safety plan.
As soon as the analyses is complete it will be shared with the NSF.
The observatory expects to remove the damaged cable and socket shortly after that. With those pieces in hand a full forensic investigation of the failed cable and socket will follow.
“We know the process is taking a long time and we are eager to begin repairs,” said Arecibo Observatory Director Francisco Cordova. “However, this is a big and complex facility, so it is taking some time to ensure we are doing things right. We have to be sure we are taking all factors into consideration before moving forward with putting people on the telescope to remove those pieces. Once those are in hand, we expect the timeline to pick up the pace.”
While the main dish is offline, Arecibo’s light detection and ranging (LIDAR) operations and the Remote Optical Facility (ROF) continue to operate, because they were not damaged in the incident. The ROF is located on the island of Culebra off the eastern side of Puerto Rico. Scientists using LIDAR at Arecibo are conducting a variety of research projects including meteor composition studies. The ROF hosts a variety of passive optical and radio equipment.
The Arecibo Observatory is home to one of the most powerful telescopes on the planet. The
facility is used by scientists around the world to conduct research in the areas of atmospheric sciences, planetary sciences, radio astronomy and radar astronomy. Arecibo is also home to a team that runs the Planetary Radar Project supported by NASA’s Near-Earth Object Observations Program in NASA’s Planetary Defense Coordination Office through a grant awarded to UCF.
At a minimum the Arecibo Observatory expects to update media as the following milestones are achieved:
* When a plan and schedule for temporary repairs is determined;
* When the failed cable and socket are removed;
* When root cause of cable failure is determined;
* When a plan and schedule for permanent repairs is ready;
* A change in operational status at the Arecibo Observatory.
Zenaida Gonzalez Kotala
UCF Office of Research
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