Webb follows a halo orbit around the moving Sun-Earth L2 region, where one sunshield can block the Sun, Earth and Moon, but the design leaves no Hubble-style repair plan.
The James Webb telescope does not orbit Earth: it circles the Sun–Earth L2 point 1.5 million kilometres away, keeping its mirror permanently shielded from the Sun—and unlike Hubble, it was never designed for astronauts to repair.
The Long View