Failure hits NASA's 'CO2 Hunter'

Nasa's first dedicated mission to measure carbon dioxide from space has failed following a rocket malfunction. Officials said the fairing - the part of the rocket which covers the satellite on top of the launcher - did not seperate properly. Data indicates that the spacecraft crashed into the ocean near Antartica. The $270 million mission was launched on a Taurus XL - the smallest ground-launched rocket currently in use by the U.S. space agency. This mission was billed as "NASA's global warming satellite"
Since its debut in 1994, the Taurus II rocket has been flown eight times, with six successes and two failures including this launch. Thats a 75% successful rating. This was the first time NASA has used the Taurus XL. Why didn't NASA use a more reliable rocket for this launch? These are a few of the rockets that could have been used ; LIDOS, Atlas V411 or Atlas V421, Delta II, AMC-14, LGM-30G minuteman III, Pegasus XL. These rockets all have a 100% orbital success rate. Could it be that they did not want to reveal the reasons for carbon dioxide and the true reason for global warming? Why did it take NASA nine years to launch this spacecraft?