Hubble Space Telescope launched

Space Shuttle Discovery carried the Hubble Space Telescope into orbit on 24 April 1990. At 2.4 metres in diameter and 13.2 metres long, Hubble was the largest optical telescope placed in orbit — designed to observe objects 50 times fainter and with 10 times the resolution of ground-based telescopes, free from the blurring effect of Earth's atmosphere.

When the first images arrived, they were blurry. The primary mirror had been ground to the wrong shape — off by just 2.2 micrometres, about one-fiftieth the width of a human hair. The error had been introduced because the testing instrument was itself incorrectly assembled, and the mistake was not caught before launch.

In December 1993, a seven-astronaut Shuttle crew installed corrective optics (COSTAR) and a new camera during a landmark servicing mission that required five consecutive days of spacewalks. Subsequent servicing missions in 1997, 1999, 2002, and 2009 replaced instruments and extended the telescope's life well beyond its original design.

By 2024, Hubble had made over 1.5 million observations of roughly 50,000 celestial objects and contributed to more than 21,000 peer-reviewed scientific publications, helping determine that the universe is 13.8 billion years old and that its expansion is accelerating — work that earned the 2011 Nobel Prize in Physics.