2011 Glory - Failed Mission

The NASA Glory satellite, intended to study aerosols and solar irradiance for climate research, was originally scheduled for launch in November 2010. However, this launch was postponed due to problems with its solar arrays detected during ground testing. 
The launch was rescheduled for February 2011, and ultimately took place on March 4, 2011. Unfortunately, the launch of the Glory satellite resulted in a failure to reach orbit due to the payload fairing (nose cone) of the Taurus XL rocket failing to separate properly. This failure was attributed to faulty materials provided by a subcontractor, and it led to the satellite and launch vehicle crashing into the Pacific Ocean.