The Vera C. Rubin Observatory is one of the next-generation large optical telescopes under construction in Chile. Others include the Extremely Large Telescope and Giant Magellan Telescope. Rubin’s camera is now almost completed. 

With only an 8.4-meter mirror, the Rubin telescope isn’t as large as the other two, but it will conduct surveys of the entire sky over several nights. The name of the survey is the Legacy Survey of Space and Time, a backronym of the original name of the telescope, the Large Synoptic Survey Telescope.  

The survey camera has a 3.2-gigapixel sensor composed of 189 individual CCDs in groups of five-by-five grids. Besides the sensor, the camera has three lenses to focus the light from the telescope’s mirror onto the sensor, two of which will be fitted to the telescope structure. The largest lens is 157 centimeters across and is the largest high-precision optical lens ever made. The third lens, on the camera body, is a mere 70 centimeters in diameter.

Besides the sensor and lenses, the camera has its own cooling cryostat to keep the detectors at -100 degrees Celsius. 

The camera’s six-slot filter wheel has yet to be installed. Once that is done, the camera will be closed up and tested in a clean room prior to being shipped out to Chile. First light is set for 2024.

More Information

The World’s Largest Camera Is Nearly Complete (IEEE Spectrum)