In vehicle crash tests, engineers use dummies to help them to assess the way passengers will be affected if they are involved in an accident. Something similar is currently happening at the GTC: Models of some of the telescope’s components are being installed to simulate the presence of the real thing during testing.
The Cassegrain focus instrument, the secondary and tertiary mirrors, and each and every one of the 36 primary mirror segments, will all have models standing in for them.
To keep it balanced, the GTC has been fitted with a system of counterweights installed at various points throughout its mechanical structure - at the primary mirror cell, the elevation ring and the
secondary mirror spider.
These points can be weighted with 50, 25, 10 and 5kg weights until balance is reached.
It’s all just a question of weight!
Natalia R. Zelman