LSST PRIMARY/TERTIARY MIRROR (M1M3) ARRIVES ON CERRO PACHÓN
May 11, 2019 – This morning, a unique astronomical mirror reached its new home in the Andes Mountains of Northern Chile. This incredible mirror will enable the Large Synoptic Survey Telescope (LSST) to catalog an estimated ~40 billion celestial objects—more objects than there are humans on earth. LSST will scan the entire visible sky every few nights, visiting each location approximately ~1000 times during its ten-year survey, which is scheduled to begin in 2022. With these fast, repeated observations LSST will open a new window to the changing Universe, providing countless new opportunities to do science with transient objects such as asteroids and supernovae. Additionally, with the wide field of view made possible by this mirror, LSST will advance the study of dark matter and dark energy.
Servers already installed in the new computer room
May 3, 2019 - CC-IN2P3 is one of the computing facilities that will be responsible for processing and storing data collected by LSST during Operations. The campaign to upgrade the center’s power and cooling infrastructure in preparation to host LSST data has entered its final phase. Located in Lyon, France, CC-IN2P3 has two computer rooms of 850 m2 each (9,150 ft2) hosting about 18,000 CPU cores, 28 PB of disk storage, and four automated tape libraries where 63 PB of data are stored. These resources are routinely used by several scientific projects, 24/7.
April 9, 2019 - The 8.4-meter LSST Primary/Tertiary Mirror (M1M3) set sail from Houston, Texas, on Friday, April 5th! Along with some other LSST cargo, the M1M3 is securely stowed aboard the BBC Manitoba for an ocean voyage to Coquimbo, Chile; the trip is expected to take about five weeks. You can track the progress of the ship by entering the vessel's name in the search bar at this website.
March 26, 2019 - UPDATE: The M1M3 has arrived in Houston and is now waiting for the ship that will take it to Chile. The trip from Tucson to Houston was uneventful for the mirror, but sparked a lot of curiosity from motorists who had to make way for this very oversized load! More photos, provided by transport company Precision Heavy Haul, Inc., are available in the LSST Gallery.
March 5, 2019 - The object in this photo, called the calibration screen reflector, was manufactured in the National Optical Astronomy Observatory (NOAO) instrument shop, which is located in the same building as the LSST Project Office in Tucson, Arizona. Our talented instrumentation team has been working on this piece of equipment for many months, and it shows! The reflector will be an important component of the calibration system inside the dome of LSST; this system is designed to determine how real-world factors like dust, and evolution to the sensitivity of the equipment over time, affect the images taken by the LSST Camera.
February 8, 2019 - The challenge to viewing and imaging celestial objects from the Earth’s surface is that the Earth’s atmosphere distorts light from space. When you look up at the stars and see them twinkle, you’re experiencing this phenomenon; light from stars is (generally) constant, but the light that reaches your eyes has been pushed around by turbulence in the Earth’s atmosphere. That turbulence is caused by the interaction of varying temperature and density layers between the Earth’s surface and space. Twinkling stars might be pretty to look at, but they’re pretty annoying for scientists who want a crisp, clear view of the objects they’re studying.
January 28, 2019 - The LSST Primary/Tertiary Mirror (M1M3) is currently in the Richard F Caris Mirror Lab at the University of Arizona for optical testing. In January, the M1M3 on its support system was positioned at the bottom of the lab’s interferometry tower in anticipation of two test campaigns. The first, which has just concluded, took place from January 14-25. The second campaign is scheduled for February 11-22.
The tests use specialized optical equipment to evaluate the figures of the M1 and M3 mirror surfaces. Separate instruments, called interferometers, are used to perform measurements on each of the two mirrors that make up the monolith. The interferometer used to test M1 is at the very top of the tower, and the one used to test M3 is lower down, on a movable bridge. The mirror surfaces are tested separately, first M1, then M3, then M3 again, then M1. When M1 is being tested, the lower interferometer is moved out of the optical path.
During the test process, the interferometer in use emits two beams of light. One travels to the mirror and bounces back, and the other goes to a reference within the interferometer. The interaction between the two beams of light is recorded in an image called an interferogram (the black and white image in the photo to the left). The lines in the image are called interference fringes, and each one represents approximately 300 nanometers. A tight grouping of lines indicates a steep change in the height of the surface, much like tight lines on a topographic map indicate steep terrain. A “perfect” mirror interferogram would be a solid color, because its measurements would be recorded as a single fringe. But according to LSST Telescope and Site Mechanical Engineer Tucker Booth, achieving perfection on individual mirrors isn’t the goal. Instead, it’s the optimization of the entire M1M3 monolith that will ensure the best possible images during LSST Operations.
Allowing adequate time for optical testing, analysis, and optimization in Tucson reduces the work that will have to be done to prepare for operations once the telescope is assembled in Chile. Additionally, the unique testing environment available at the Richard F Caris Mirror Lab isn’t available in the summit facility building, so LSST is fortunate to have access to this world-class facility for the M1M3 optical test campaigns. M1M3 is currently scheduled to ship from the U.S. to Chile in May.
January 14, 2019 - The 233rd Meeting of the American Astronomical Society (AAS) wrapped up on January 10; this year’s winter meeting took place in Seattle, WA, with more than 3000 people registered. LSST staffed an exhibitor booth during the meeting within the National Science Foundation’s (NSF) Pavilion, giving project updates and answering questions from conference attendees. Numerous posters and talks were presented by LSST Project and Science Collaboration members.
It’s hard to believe another calendar year is drawing to a close! 2018 was jam-packed with activity for LSST, so it’s no wonder the year seemed to pass in a flash. Here’s a look back at some of the major accomplishments and milestones the LSST Project celebrated this year:
The LSST Secondary Mirror (M2) also arrived in Chile on December 7th, and will reach Cerro Pachon before the end of the year. What’s in store for 2019? Delivery of more critical pieces of equipment to the summit, including the Telescope Mount Assembly and M1M3 Mirror and Cell Assembly; coating of the Secondary Mirror (M2) on the summit; progress towards determining the LSST observing cadence; and much more. Visit lsst.org and follow LSST on social media for the latest updates!
It is with great regret that we inform you of the sudden passing of Jim Parsons, one of our NCSA colleagues. Our thoughts are with his family and our team at NCSA. There will be a DM community post (https://community.lsst.org/c/dm) with arrangements when we know them, and an opportunity to express sentiments to be forwarded to the family.
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. NSF and DOE will continue to support LSST in its Operations phase. They will also provide support for scientific research with LSST data.