Which space telescope launched in 1990 and transformed astronomy?

The Hubble Space Telescope launched in 1990 and transformed astronomy.

NASA launched Hubble aboard the Space Shuttle Discovery on 24 April 1990, and it was deployed into low Earth orbit on 25 April. Because it observes above Earth's atmosphere, it can produce exceptionally sharp images at visible, ultraviolet and near-infrared wavelengths.

A flaw in Hubble's primary mirror initially caused blurry images. Astronauts installed corrective optics during the first servicing mission in December 1993, restoring the telescope's intended performance.

Hubble has helped measure the expansion rate of the universe, study the ages of stars and observe distant galaxies. The James Webb Space Telescope, launched in 2021, complements Hubble with stronger infrared capabilities rather than replacing all of its observations.