Application: a Giant Telescope.
When in the 1980's, astronomers from around the world had studied all the universe that was reachable by the
Mt. Palomar's very large - for its time - telescope, they turned to the engineers and asked them for 8 m, 10 m and larger telescopes.
The primary mirror of such large telescopes would have required casting and polishing huge blanks of glass which
would have weighed 10 or more tons. Just having to replace one would have taken up to 4-5 years.
Engineers came up with the idea of segmented mirrors or very thin meniscus mirrors.
The actuators supporting these segmented or thin mirrors had to repeatedly reposition them within a small fraction of a micrometer.
Satellite Roller Screws became the muscle of choice of these incredibly accurate actuators.
