In February 2009, NASA launched the Orbiting Carbon Observatory (OCO) with a plan to map the distribution of Carbon Dioxide (CO₂) throughout the Earth's atmosphere.  This launch failed when the shroud protecting the satellite failed to separate from the rocket, leaving the launch vehicle too heavy to attain orbit.

Currently using a network of ground-based sites, the US Department of Energy was intending to make use of the OCO to monitor atmospheric CO₂ on a far wider scale.

Following the failure, the US Congress authorised NASA to allocate funds in fiscal year 2010 for a replacement mission.  This week, NASA awarded contracts for the replacement mission.

"NASA has selected Orbital Sciences Corp. of Dulles, Va., to launch the Orbiting Carbon Observatory-2 (OCO-2) mission. The spacecraft will fly in February 2013 aboard a Taurus XL 3110 rocket launched from Vandenberg Air Force Base in California.  The total cost of the OCO-2 launch services is approximately $70 million."

According to NASA, "OCO-2 is a NASA's first mission dedicated to studying atmospheric carbon dioxide. Carbon dioxide is the leading human-produced greenhouse gas driving changes in the Earth's climate. OCO-2 will provide the first complete picture of human and natural carbon dioxide sources and 'sinks,' the places where the gas is pulled out of the atmosphere and stored.  It will map the global geographic distribution of these sources and sinks and study their changes over time."

This is a critically important mission to improve our understanding of the evolution of CO₂ in the atmosphere.  Let's hope it doesn't fail a second time.