[aeroman]

There were a few Earth Observation missions that didn't make orbit about 10-15 years ago. This was due to a failure of the Taurus-XL fairing separation.

The orbiting carbon observatory (OCO) failed to reach orbit in 2009 [1]. It got a replacement (a good thing, given how important these measurements are.

Glory [2] would have had a really cool polarimiter (measuring light polariasation as well as radiance, in a range of different directions, but it failed in 2011 for the same reason as OCO. Unfortunately, it didn't get a replacement.

[1] - https://en.wikipedia.org/wiki/Orbiting_Carbon_Observatory

[2] - https://en.wikipedia.org/wiki/Glory_(satellite)