The Hubble Space Telescope began its outer-space adventures in April 1990. Although the project had been in the works for 44 years, NASA only noticed a pretty significant problem once the telescope was actually launched. The state-of-the-art machine designed to provide us with our first real glimpses of quasars and distant galaxies was sending fuzzy pictures back to Earth. The Hubble telescope had a vision problem. Nearly four years and $700 million later, NASA finally repaired the telescope's incorrectly ground lens.
Top 10 NASA Flubs
Even as NASA welcomes home the crew of one its final shuttle missions (just two days after commemorating the 40th anniversary of the miraculous return of the Apollo 13 crew), it's grappling with how to adapt to a new President's plan for its future. TIME takes a look at the dimmer moments in its history: the canceled projects, the failures and some notable mishaps