The History of Arecibo’s Legacy Telescope to Impact the Future, Thanks to the AO Salvage Survey Committee

The collapse of the 305 m radio telescope at the Arecibo Observatory (AO) on December 1, 2020 continues to be felt throughout the local and scientific communities. While it is no longer collecting scientific data, components of the telescope could be preserved for historical and educational purposes.

The Arecibo Observatory Survey Salvage Committee (AOSSC) was established by the University of Central Florida (UCF) and the National Science Foundation (NSF) in January of 2021 with the purpose of recommending the retrieval of items that have potential historical significance, or that might be leveraged for instrument research or informal education. The committee was composed of scientists and historians from the AO Science and Visitor’s Center, the Smithsonian Institution, NSF, and AO users and staff.

In November of 2021, the AOSCC completed their report, which can be found here: AOSCC Report.

“In order to have a minimal impact on the environment, the clean-up of the site happened very quickly,” says Ms. Luisa Fernanda Zambrano-Marin, an AO analyst and co-Chair of the AOSCC. “This meant we had to work fast to identify the most critical pieces to salvage.”

Through nineteen weeks of weekly meetings, site visits, and a close study of hundreds of high-resolution survey photographs taken by AO-operated drones, the committee developed a database of high-priority items and cataloged the actual pieces collected during the emergency cleanup. “We marked the salvageable items with pink neon construction tape to indicate that they should not be carried away by the clean up crew,” says Ms. Zambrano-Marin.

While all of the salvaged parts of the telescope have important historical and educational purposes, committee members had unique connections with many of the recovered items.

“From my own work, finding the S-band radar klystrons meant a lot, having used them to map the Moon and Venus,” says Dr. Bruce Campbell of the Smithsonian Institution, who served on the AOSSC.

“As a passive radio astronomer, I was gratified that elements of some of the Gregorian Dome receivers that I personally used had survived, including parts of the LBW, 327-MHz, 439G, SBH, and XB receivers,” says Dr. Christopher Salter, former Head of the Astronomy group at AO, who served on the AOSSC. “Particularly gratifying was the relatively good state in which the ALFA 7-beam feed array was recovered.”

Recovered ALFA Receiver L-Band Feed Array

Landing step from cable cart that led onto the platform

Dr. Salter added that recovering the step that led up to the suspended platform from the cable car was a particularly emotional find. “This was the ‘first step for humankind’ into the unique world and experience one could have while on the telescope’s platform, way up there in the sky!”

Some of the historical items have already been put on display at Arecibo’s Ángel Ramos Science and Visitor’s Center, which reopened to the public on March 10, 2022. Among the displayed items are the ALFA receiver, an S-band klystron, and pieces of the Gregorian dome and the platform.

“It's so important to be able to show visitors to the observatory or a museum the ‘real thing’ - something that actually captured the radio signals from a pulsar or transmitted a radar signal all the way to Titan,” says Dr. Campbell. “Those artifacts also provide a link to the human stories of the engineers and scientists that built and used them.”

The ultimate fate of the recovered pieces of the legacy telescope is yet to be determined. The final recommendations from the AOSSC include the need for action to protect the artifacts from further damage or corrosion, distribution of historic and technical information about the instruments and structural elements to museums and universities, and the formation of a follow-on group to consider the long-term preservation and educational potential of the recovered material.

“I hope that in the long term these objects will be preserved and displayed in ways that tell those stories and inspire students to go into fields like engineering, radio astronomy, or planetary science,” says Dr. Campbell.

Dr. Salter agreed. “The hope is that they will be displayed where, and in such a fashion that, they can be appreciated by both the student body and general public to inspire excitement in the future of radio astronomy, and Arecibo's place within it.”

On the importance of sharing the recovered items with the public, Ms. Zambrano-Marin adds, “This is history. This is part of the bulk of technological wonders that allowed us to make great discoveries in astronomy, planetary science, and space and atmospheric science.”

The Arecibo Observatory is grateful for the hard, diligent work of the AOSSC to ensure that the pieces of the legacy 305 meter telescope can serve as an inspiration to the next generation of scientists so that the telescope can continue its decades-long role as an integral part of radio science.

The following people were part of the AOSSC and contributed to the report:

• Carlos M. Padín, Chair, AO Science and Visitor’s Center

• Luisa Fernanda Zambrano-Marin, Co-Chair, AO Science Staff

• Olga Figueroa, AO Management

• Luis Quintero, AO Staff, Electronics

• Gabriel Altuz, AO Operations

• Alfredo Santoni, AO Staff, Electronics

• Mike Sulzer, AO Staff, Atmospheric Sciences

• PK Manoharan, AO Staff, Astronomy

• Carmen Pantoja, AO User, University of Puerto Rico

• Chris Salter, AO User, Adjunct Scientist, Green Bank Observatory

• Bruce Campbell, AO User, Smithsonian Institution

• Leo Slater, National Science Foundation (NSF) historian

Observers:

• Alison Peck, NSF

• Lori Price, Jacobs

Article written by Dr. Tracy Becker - AO Collaborator / SwRI Research Scientist Contact: tbecker@swri.edu

Arecibo Media Contact Ricardo Correa Universidad Ana G. Méndez (UAGM) 787-878-2612 ext. 615 rcorrea@naic.edu

Keywords: arecibo, observatory, salvage, ALFA, Receiver, L-Band, Feed, Array, University, Central, Florida, national, science, foundation, visitor, center, management, legacy, history