The Hubble Space Telescope became a source of national mockery when its mirror was offset by 1/50th the width of a hair.
As you likely know, the Hubble Space Telescope, responsible for a multitude of the pictures of space we fawn over, is a satellite telescope launched in 1990. In its first 15 years floating 353 miles above Earth’s surface, Hubble recorded over 700,000 images. It has gained notability in part because of its spectacular view above Earth’s atmosphere. Because our view of space on Earth is distorted by air pockets, we see a diminished version of the view from outside the atmosphere.
The air pockets in the atmosphere (as well as the difficulties light has penetrating our atmosphere) are responsible for stars having their “twinkle” look. Hubble’s mirror is responsible for collecting the light from stars necessary to capture images. Before launch, it had been designed to be visited periodically by astronauts for repair and upgrades. The most famous of the visits occurred in 1993. It had been discovered that Hubble’s primary mirror was out of shape on the edges by 1/50 the width of a human hair.
This defect made it difficult to focus, placing it at the butt end of many jokes focused on its years of development apparently being for naught. With each visit to the Hubble, its capabilities have improved, providing the people of Earth with great images of outer space.