On 16 July 2012, NASA selected the ULA (United Launch Alliance) Delta II 7320-10C launch vehicle to place the OCO-2 observatory into orbit.
The Delta II is part of a launch vehicle family that first entered service in 1989 and has recorded well over 140 successful launches to date. The Delta II has also been selected to place a number of other Earth-orbiting satellites into orbit including SMAP (Soil Moisture Active Passive) mission and ICESat-2.
Delta rockets have been carrying NASA spacecraft aloft since the 1960s. You can share in the excitement of the live countdown via NASA TV or the Web. Coverage usually begins two hours prior to liftoff, and you can use the countdown events below to track the prelaunch milestones and learn about the Delta II Countdown process.