Not all the most interesting telescopes need to live in space. The Large Synoptic Survey Telescope (LSST) will sit on top of a mountain in Chile some 8,800 feet up and snap 3.2-gigapixel (3,200-megapixel) images of the sky every 20 seconds. All told, it will be able to snap digital images of the entire southern sky every few nights. By taking relatively long 15-second exposures, scientists will be able to study the early universe, track dimly-lit asteroids and better understand dark energy.
The LSST cameras has 32 times the resolution of the best consumers shooters out there in order to image the maximum amount of sky possible. It’s also the “largest CCD [charge coupled device] mosaic in the world,” according to the contractor that worked on it. To focus all that light, the telescope has a very wide 3.5-degree diameter field of view and extremely fast aperture, giving it an immense 319 meters-squared, degrees-squared “entundue” — three times more than the best current telescopes.
To achieve that feat, it will use three mirrors, with the primary at 8.4 meters (28 feet) in diameter, the secondary at 3.4 meters and the tertiary at 5 meters. The challenge is to get rid of any aberrations, which is where the lens above comes into play.
LSST L1 lens
SLAC said that the 1.55-meter (5.1-foot) L1 lens shown above is the “largest high-performance optical lens ever fabricated.” It was designed by Lawrence Livermore National Laboratory (LLNL), based on work spanning nearly two decades, and fabricated using very advanced optic systems. It was built, along with the 1.2-diameter L2 companion lens, by Ball Aerospace and subcontractor Arizona Optical Systems in a process that took five years.
“The success of the fabrication of this unique optical assembly is a testament to LLNL’s world-leading expertise in large optics, built on decades of experience in the construction of the world’s largest and most powerful laser systems,” said physicist Scot Olivier.
The camera itself is the size of a small car and weighs more than three tons. Each massive image it produces will be a gold mine for scientists, and it’s expected that the LSST will detect about 20 billion galaxies during a 10-year time frame, while also creating time-lapse movies that could reveal changes in galaxies and stars.
The images won’t just benefit scientists. “Anyone with a computer will be able to fly through the universe, past objects 100 million times fainter than can be observed with the unaided eye.” SLAC and LSST hope it will become a platform for crowd-sourced astronomical discoveries. The LSST is scheduled to start imaging the southern sky by 2023.
Suffice to say, this is one valuable piece of glass, so moving it from Tucson, Arizona to the SLAC National Accelerator Laboratory in Menlo Park was a bit of an event, according to SLAC’s Flickr site. And yes, it was apparently shipped by FedEx.