Today in 1990, the Hubble Space Telescope (named for astronomer Edwin Hubble) sent its first photographs to NASA. The pictures were noticeably blurrier and of lower quality than what was expected. It was discovered that this was due to an incredibly minor polishing mistake on one of the primary mirrors. In December 1993, a team was sent out to replace the mirror and perform various other tweaks and upgrades. By January 1994, the HST was fully operational as originally intended. The Hubble has been one of the most important boons for both data collection and public relations for NASA. It still remains completely functional today, and is expected to continue operating until 2040.
Image Credit: NASA