Management Update (October 12, 2020) by Director Eng. Francisco Cordova

Repairs Update


October 12, 2020

Dear AO Community,
  Ray and I made a commitment to our staff and the User Community to provide periodic updates as the work of restoring the Arecibo Observatory to its full capability advances. We continue to make progress, but the process is slow as we develop a comprehensive plan for facility repairs while prioritizing the safety of our staff.

Our staff, as well as external firms that have been hired, are working diligently to understand the cause of the failure and to return the telescope to normal operations as soon as possible.

The following tasks/actions have been completed since our last communication on September 10:

  • A full structural model has been developed for the Arecibo Observatory platform, towers and suspension cables. The model has enabled us to better understand margins of safety and capacities for the existing structure and to take appropriate action in repair plans as installation of temporary repairs and further assessment proceeds.

  • Cable sag surveys were completed for all auxiliary cables. These surveys were necessary to calculate actual loads on the cables, and properly calibrate the structural model.

  • A complete safety assessment plan has been developed, making sure that quantifiable measure of structural integrity and capability are captured before crews are allowed to perform temporary repair work in those areas.

  • The “socket” that was involved in the failure was removed on Sept. 23 and the hardware was shipped to Florida for forensic evaluation at the NASA Kennedy Space Center. Experts at the center will conduct nondestructive analysis and tests in conjunction with the forensic engineering firm leading the investigation. It is expected that this work will be completed by the end of October.  The forensic investigation will also include evaluation of the failed cable and eventually, the socket that is still attached to the platform.

  • Over the last week we initiated the installation of an instrumentation system, which will continually monitor the condition of the structure. This is necessary to help us minimize the risk to our staff working on and in proximity to the structure.  The instrumentation includes strain gauges, tilt meters and eventually will include an acoustic measurement system.  All of this will enable the team to assess the condition of the structure as we move forward.

  • The NSF has completed the review of a temporary repair plan. An order for temporary friction clamps has been placed. The friction clamps will be installed at 2 backstay cable locations and are meant to bypass the cable load as a precaution in case these cables fail at their sockets.  These sockets were identified to be problematic as cable/socket separations were observed to be beyond acceptable thresholds.  An order for a replacement auxiliary suspension cable has also been placed and is expected to be on site by middle of December in addition to its matching pair, and two temporary cables to be utilized in the repair.

The NSF has asked the observatory team to develop a supplemental proposal to cover the costs of these analysis, immediate facility stabilization efforts, and completion of engineering evaluation and design for the repair necessary to return to operational status. The AO team is diligently working this, which includes a detailed project execution plan, and a cost estimate for these repairs.

Bottom line… we are making significant progress towards restoring the operational capability of this historic facility. We have created a webpage where we are posting updates on the repair status of the facility which you can access at

We are extremely grateful to the continued support we’ve received from the AO community, and know that we are always available to answer any questions or concerns the community may have.

Francisco Cordova
Director - Arecibo Observatory
University of Central Florida

Ramón (Ray) Lugo 
Director – Florida Space Institute 

Communications Director
Ricardo Correa
Arecibo Observatory
787-878-2612 ext. 615

Keywords: arecibo, observatory, management, update, repairs, cable, replacement