Hubble’s Glasses Save the Cosmos: How a Flawed Mirror Became the Most Productive Telescope
Launched in 1990 with a mirror polished to the wrong shape by a measurement error, Hubble produced blurred images. A 1993 servicing mission to the space shuttle Endeavour installed COSTAR and the WFPC2 instrument, effectively giving the telescope “glasses” and fixing the vision. The repair transformed Hubble into the most productive observatory in history, enabling landmark discoveries and earning it a lasting reputation as a public-facing science icon; COSTAR was retired later as each instrument gained its own correction.