lsstpo's blog

April 26, 2018 – An LSST cross-project team met at the National Center for Supercomputing Applications (NCSA) earlier this month to conduct the latest in a series of Early Integration Pathfinder Activities. This activity focused on simulated control and image collection for the nominal Auxiliary Telescope visit sequence. The exercise was the culmination of intense effort from a distributed group of LSST project members, and it offered the opportunity for participants representing different subsystems to align expectations, resolve issues, and determine priorities for next steps.

April 11, 2018 - The LSST Network Engineering Team is pleased to announce the first successful transfer of digital data over LSST/AURA 100 gigabit per second fiber optic networks from the Summit Site on Cerro Pachón, Chile to the Base Site in La Serena, Chile and on to the Archive Site at NCSA in Champaign, IL. This event took place in December 2017 and demonstrated not only performance and continuity across all hardware segments of the network, but a well-coordinated effort by multiple international engineering teams in support of LSST.

March 23, 2018 - After three years of construction work on Cerro Pachón, general contractor Besalco Construcciones achieved substantial completion of the LSST Summit Facility on February 28, 2018. On that date, the building keys were officially turned over to LSST Construction Inspector Jaime Seriche and LSST Site Manager Eduardo Serrano. Although 20-30 Besalco workers will remain on-site for a few more weeks, addressing punch list tasks, LSST now has authority over the occupation of the facility and the site work schedule. Current activity in the building includes IT equipment installation, furnishing of offices, and post-construction projects for various LSST subsystems.

February 27, 2018 - In calendar year 2018, almost $100M of equipment will be transported to Cerro Pachón from the U.S. and around the world for integration into the LSST summit facility building. Major items include the Telescope Mount Assembly (TMA), the Coating Chamber, the Dome, the Primary/Tertiary Mirror (M1M3) and Secondary Mirror (M2), the mirror cells, and the hexapod rotator (with its twin spare). These items will be gathered from several locations, including Rochester, NY; Tucson, AZ; Denver, CO; Italy, Spain, and Germany, and shipped to the Chilean port of Coquimbo for ground transport to the summit. The designer of much of the complex, but flexible, logistics program is LSST Principal Surveyor Michael Logue.

February 16, 2018 - An Education and Public Outreach (EPO) focus group for teachers was held in Tucson on February 3-4. Led by LSST Education Specialist Ardis Herrold, the event gathered 11 high school and college educators from across the U.S. to solicit feedback on prototypes of the online educator tools, including Jupyter Notebook-based interactive astronomy investigations, currently being developed by the EPO team. Opinions provided by the participants will help guide future stages of EPO product development, ensuring the continued alignment of EPO products with educator needs.

January 22, 2018 - To ensure optimal performance of the LSST telescope, a regular cleaning schedule of its mirrors will be implemented during operations. Weekly, the Primary/Tertiary Mirror (M1M3) and Secondary Mirror (M2) surfaces will be cleaned by spraying the surfaces with a carbon dioxide (CO₂) “snow” which removes dust particles and other contaminants. Approximately every six months, M1M3 will be cleaned with neutral soap and water using very soft chamois mops, followed by de-ionized water rinsing and drying using small air knives around the mirror cell. Both of these cleaning procedures take place without removing the mirrors from the telescope, and are completed within one summit working day. Neither the CO₂ nor wet contact wash will impact the nightly observing schedule.

In addition to these preventative maintenance activities, the mirrors will be stripped of their reflective coatings, washed, and recoated every few years. We anticipate the M1M3 (coated with aluminium) will be cleaned and recoated every 2 years, and the M2 (coated with protective silver) every 5 years. Reflectance monitoring will allow us to predict when this more time-intensive work is necessary, and it will likely be coordinated with other scheduled downtime.

The washing station, which provides for pristine optical surfaces before coatings are deposited, is a deliverable part of the coating plant contract. A Provisional Acceptance Test of the washing chamber will take place later this month at the Von Ardenne facilities in Dresden, Germany. The review includes observation of the washing boom, seen in this 30-second video provided by LSST Coating Chamber Engineer Tomislav Vicuna. This special machinery will remove the old mirror coating and wash the mirror prior to moving it into the coating chamber for recoating.

A related story about the LSST coating chamber, from March, 2017, can be found here.