The Hubble Space Telescope has lasted for 19 years, because it was designed mostly with parts that astronauts could replace on spacewalks.
Not on this mission.
A key instrument -- a spectrograph that can, among other things, measure the chemical composition of distant objects in the cosmos -- had lost power. NASA decided that instead of replacing the whole thing, it would have the astronauts fix it by hand on the fourth spacewalk of their mission to repair Hubble.
The job fell to spacewalker...Full Story