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Telescope Mount


  • The steel telescope mount was built in Spain, and shipped to Chile as a 26-piece cargo shipment. The longest piece was 46 ft (14 m) long, and 15 ft (4.5 m) high. Once all the shipping crates arrived in Chile, they were transported to Cerro Pachón and the structure was re-assembled on the telescope pier inside the observatory.
  • The dome and the telescope operate separately, so while the dome moves more slowly than the telescope, it can creep along to the next observing position while the telescope finishes taking an image and then catches up with the dome.
  • There are literal miles of cables that provide utilities like electricity, communications, and compressed air to the different parts of the telescope. Some of these cables are attached to a “spider spindle” in the center of the telescope mount that operates like a maypole: the cables can wind and unwind around the spindle without getting tangled as the telescope rotates.

The huge mirrors and sensitive camera in the Rubin Observatory telescope couldn’t do much without the huge steel structure that supports them—like the organs in a human body, they need a skeleton to hold them together! This steel structure, called the telescope mount, was designed to be rigid yet relatively lightweight. This helps reduce vibration as the telescope darts from one field of view to the next, and that means it can be ready take another sharp, clear image after just a few seconds.

The telescope is powered by linear motors, so there’s almost no noise or vibration as the telescope moves from one position to another. A huge bank of capacitors under the telescope provides electricity to the motors; the capacitors were installed before the telescope was put together above them, and they’re designed to last for the whole ten-year LSST survey and beyond. An interesting thing about these capacitors is that when the telescope slows down and stops at a new observing point, the slowing motion sends energy back to the capacitors, helping charge them up again and making the observatory environmentally greener. You might have heard of this concept of "regenerative braking" in gas-electric hybrid vehicles.

Because the telescope mount is so big, the engineers who designed it included built-in equipment that helps Rubin Observatory staff members access the different parts of the telescope for cleaning and maintenance. For example, staff will use a set of moving platforms to safely access the camera where its installed on the telescope mount—many meters above the ground.

The optical components of the telescope—the camera, the combined primary/tertiary mirror, and the separate secondary mirror—can all be removed from the telescope mount when necessary for major maintenance or repairs. The mirrors, for example, will need to be stripped and recoated a few times during the ten-year survey. When it’s time for this activity, we'll remove the mirrors from the structure and transport them to the maintenance floor of the facility using carts mounted on rails set in the floor, and a huge elevator platform (intended for equipment only—no people are allowed to ride) will move the heavy but delicate mirrors between floors.

Learn more about Rubin technology