No 6. The Hubble Telescope
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.
NASA has recently upgraded the Hubble to get better images
No 5. The Final Apollo Missions
NASA planned 13 manned missions to space, starting with Apollo 8. The first 10 went relatively fine (well, except for Apollo 13). But Apollo 18-20 never got off the ground. Literally. Apollo 20 was canceled first; its rocket was needed for another project. Then a series of congressional budget cuts required NASA to scale back on costs. In September 1970, Apollo 18 and Apollo 19 were scrapped. These days, you can see Apollo 18’s Saturn V rocket lying on its side in Houston. It is now essentially a $225 million lawn ornament.