3200-megapixel LSST, the world’s biggest camera will take high quality pictures of the universe.
Rubin Observatory’s LSST Camera is having a moment, and it’s one that’s getting lots of media attention. Although the camera isn’t fully complete yet, all of its mechanical components are now together for the first time—in one photogenic structure. The team at SLAC National Accelerator Laboratory facilitated media visits to the clean room while the camera is positioned so that visitors can see its impressive focal plane (which contains 189 CCDs) through the camera’s lenses. In total, the SLAC team hosted 21 visitors from 14 outlets in September, representing a range of media interests—local, national, science, print, radio, video and TV.
When they’re not answering questions about the 3200-megapixel camera that will take images for Rubin Observatory’s 10-year Legacy Survey of Space and Time, the team at SLAC is testing the camera shutter and the filter exchange system, two dynamic components that were also recently installed.
Before the end of the year, the camera will undergo one final modification: the installation of an updated refrigeration system. At that point the camera will be complete and ready for final testing before it ships to Chile in May of 2023.
Largest Digital Camera
The Rubin Observatory LSST Camera is the largest digital camera ever constructed. At about 5.5 ft (1.65 m) by 9.8 ft (3 m), it’s roughly the size of a small car and weighs almost 6200 lbs (2800 kg). It is a large-aperture, wide-field optical imager capable of viewing light from the near ultraviolet to near infrared (0.3-1 μm) wavelengths. The LSST Camera is designed to provide a 3.5-degree field of view, with its 10 μm pixels capable of 0.2 arcsecond sampling for optimized pixel sensitivity vs pixel resolution.
The image surface is flat with a diameter of approximately 25.2 in (64 cm). The detector format employs a mosaic of 189 16-megapixel silicon detectors arranged on 21 “rafts” to provide a total of about 3.2 gigapixels. The camera includes a filter-changing mechanism and shutter. It is positioned in the middle of the telescope where cross sectional area is constrained by optical vignetting (edge darkening) and heat dissipation must be controlled to limit lens-deforming thermal gradients in the incoming light.
The LSST Camera will produce data of extremely high quality with minimal downtime and maintenance.
In Aug 2022, the Rubin Observatory Commissioning Camera (ComCam) was successfully installed on the Telescope Mount Assembly (TMA) on the summit of Cerro Pachón on August 24, 2022. This is the first of many optical components to be integrated with the telescope structure, and an important step towards getting real astronomical data flowing from the observatory.
ComCam is a smaller (144 megapixel), simpler version of the full 3200-megapixel LSST Camera. ComCam will be used for testing and commissioning activities prior to the installation of the full science camera, and it will produce the first astronomical data from the Simonyi Survey Telescope once the rest of the optical system is installed. This “commissioning data” will be used to demonstrate that the various subsystems of the telescope are working as designed, and the Rubin Operations team plans to release commissioning data as part of Data Preview 1, scheduled for mid-2024.
The Rubin team on the summit has been rehearsing for this installation for many months using the camera surrogate mass, a steel structure that approximates the mass of the LSST Camera (and ComCam) Assembly. The practice lifts have allowed the team to fine-tune the lifting, installation, and removal procedures before using them to install real cameras with delicate electronics.