SLAC completes construction of largest ever digital camera for astronomy

04 Apr 2024

When installed in telescope in Chile, the 3,200 MP LSST Camera will probe dark matter and more.

After two decades of work, scientists and engineers at the U.S. Department of Energy’s SLAC National Accelerator Laboratory and their collaborators are celebrating the completion of the Legacy Survey of Space and Time (LSST) Camera.

As the heart of the DOE and National Science Foundation-funded Vera C. Rubin Observatory, the 3,200-megapixel camera will help researchers observe the universe in unprecedented detail. Over ten years, it will generate an enormous trove of data on the southern night sky that researchers will mine for new insights.

That data will aid in the quest to understand dark energy, which is driving the accelerating expansion of the universe, and the hunt for dark matter, the mysterious substance that makes up around 85% of the matter in the universe. Researchers also have plans to use Rubin data to better understand the changing night sky, the Milky Way galaxy, and our own solar system.

“With the completion of the unique LSST Camera at SLAC and its imminent integration with the rest of Rubin Observatory systems in Chile, we will soon start producing the greatest movie of all time and the most informative map of the night sky ever assembled,” said Director of Rubin Observatory Construction and University of Washington professor Željko Ivezić.

To achieve that goal, the SLAC team and its partners built the largest digital camera ever constructed for astronomy. The camera is roughly the size of a small car and weighs around 3,000 kg, and its front lens is over 1.5 m (5 ft) across – the largest lens ever made for this purpose.

Another 0.9m-wide (3 ft) lens had to be specially designed to maintain shape and optical clarity while also sealing the vacuum chamber that houses the camera’s enormous focal plane. That focal plane is made up of 201 individual custom-designed CCD sensors, and it is so flat that it varies by no more than a tenth the width of a human hair. The pixels themselves are only 10 µm wide.

Highest resolution

Still, the camera’s most important feature is its resolution, which is so high it would take hundreds of ultra-high-definition TVs to display just one of its images at full size, said SLAC professor and Rubin Observatory Deputy Director and Camera Program Lead Aaron Roodman.

“Its images are so detailed that it could resolve a golf ball from around 15 miles away, while covering a swath of the sky seven times wider than the full moon. These images with billions of stars and galaxies will help unlock the secrets of the universe.”

And those secrets are increasingly important to reveal, said Kathy Turner, program manager for the DOE’s Cosmic Frontier Program. “More than ever before, expanding our understanding of fundamental physics requires looking farther out into the universe,” Turner said. “With the LSST Camera at its core, Rubin Observatory will delve deeper than ever before into the cosmos and help answer some of the hardest, most important questions in physics today.”

Video explainer

Built at SLAC National Accelerator Laboratory, the LSST Camera is the largest digital camera ever built for astronomy. The camera is at the heart of the Vera C. Rubin Observatory's 10-year-long Legacy Survey of Space and Time (LSST), which will capture the entire southern sky every 3 nights. Data from the camera will help address some of the most pressing questions in cosmology, such as the nature of dark energy and dark matter, as well as advancing the study of our solar system and the changing night sky. Video source: Olivier Bonin/SLAC National Accelerator Laboratory.