The Hubble Space Telescope
A flawed mirror is repaired in orbit, and the universe gets an age.
- When
- Era
- Contemporary, Holocene
Launched in 1990 with a mirror ground to the wrong shape, Hubble is corrected by a shuttle servicing mission in 1993 and becomes the most productive scientific instrument ever built. Its Deep Field images, pointing at apparently empty sky for days, reveal thousands of galaxies. Its measurements of Cepheid variables pinned the expansion rate and gave the universe a reliable age of about 13.8 billion years.