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.
March 9, 2018 - Exciting progress took place in February at subcontractor Asturfeito in Spain, where personnel assigned to the Telescope Mount Assembly (TMA) engaged in balancing and metrology activities.
Although LSST’s telescope will eventually be controlled by computers, current balancing activities require a manual approach in which the telescope, while floating on oil, is moved by winches. Measurements of the force on the telescope are taken to ensure the telescope is balanced whenever it’s off-zenith. This video, taken during the balancing of the elevation structure, illustrates the process.
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.
February 2, 2018 - In tandem with LSST’s construction on Cerro Pachón, a smaller telescope will soon be assembled on nearby calibration hill, a short distance away from the main LSST Facility. LSST’s 1.2-meter Auxiliary Telescope, a gift from Edgar Smith, will measure atmospheric transmission, which refers to how directly light is transmitting through the Earth’s atmosphere in a given spot, as opposed to being absorbed or scattered. Because the presence of certain molecules and particles in the atmosphere will change the color of light detected by the LSST telescope, data collected by the Auxiliary Telescope, as it mirrors the nightly movements of LSST, will inform the catalog corrections that need to be made to LSST data in order to render it more accurate.
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.
LSST Assembly Integration Verification (AIV) Manager Jacques Sebag submitted this spectacular drone footage of the LSST facility, taken on December 28. The video was taken after the LSST team collaborated with subcontractor Besalco to move the facility mobile roof to the flat area located on the north side of the lower enclosure. Congratulations to all for this achievement at the end of 2017!
December 14, 2017 – The LSST mirrors and camera are designed to be transported on carts, as complete subassemblies, from the telescope to the maintenance level within the summit facility during LSST's ten-year survey lifetime. The mirrors will be recoated approximately every two years and the camera clean room will be available to support maintenance and servicing. Because the maximum load (the M1M3 on its cart) will approach 75 tons, and the equipment must move up and down 27 meters, a custom, robust lifting mechanism is required. PFlow Industries has built a unique 11-meter square Vertical Platform Lift for LSST, and December 7, on Cerro Pachón the folding-edge structure for its movable roof was successfully installed.
Financial support for LSST comes from the National Science Foundation (NSF) through Cooperative Agreement No. 1258333, the Department of Energy (DOE) Office of Science under Contract No. DE-AC02-76SF00515, and private funding raised by the LSST Corporation. The NSF-funded LSST Project Office for construction was established as an operating center under management of the Association of Universities for Research in Astronomy (AURA). The DOE-funded effort to build the LSST camera is managed by the SLAC National Accelerator Laboratory (SLAC). The National Science Foundation (NSF) is an
independent federal agency created by Congress in 1950 to promote the progress of science. NSF supports basic research and people to create knowledge that transforms the future.