The Orbiting Carbon Observatory (OCO) was a NASA Earth System Science Pathfinder Project (ESSP) mission designed to make precise, time-dependent global measurements of atmospheric carbon dioxide (CO2) from an Earth orbiting satellite. Unfortunately, on February 24, 2009, due to a launch vehicle payload fairing anomaly, OCO failed to reach orbit.
However, in December 2009 the Congressional Conference committee directed NASA to allocate no less than $50M for the 2010 fiscal year (FY10) for the initial costs associated with an OCO replacement. Released on February 1st, 2010, the President's Budget provided adequate funding to support the launch of an OCO re-flight mission (now known as OCO-2). The OCO-2 mission underwent critical design review (CDR) in August 2010 and key design point-C (KDP-C) in September 2010. On October 2010, it began the implementation phase.
On July 16, 2012, NASA announced that it had awarded launch services contracts for three United Launch Alliance Delta 2 rockets. A little over 5 years after the OCO launch failure, OCO-2 launched from Vandenburg Air Force Base on Tuesday, July 1, 2014. Originally flown on a Taurus XL, OCO-2 flew on a Boeing Delta II 7320-10C. The Delta II is one of the most successful launch vehicles ever flown with well over 100 successful launches.
OCO-2 was built based on the original Orbiting Carbon Observatory mission to minimize cost, schedule, and performance impacts. OCO-2 was designed to have a nominal mission time frame of at least two years, but the spacecraft has continued to fly well beyond its prime mission. OCO-2's primary science objective is still to substantially increase our understanding of how carbon dioxide sources and sinks are geographically distributed on regional scales and how their efficiency changes over time.