NASA's first spacecraft dedicated to measuring carbon dioxide levels in Earth's atmosphere is in final preparations for a July 1 launch from Vandenberg Air Force Base, California.

 

The Orbiting Carbon Observatory-2 (OCO-2) mission will provide a more complete, global picture of the human and natural sources of carbon dioxide, as well as their "sinks," the natural ocean and land processes by which carbon dioxide is pulled out of Earth’s atmosphere and stored.

 

Carbon dioxide, a critical component of Earth's carbon cycle, is the leading human-produced greenhouse gas driving changes in Earth’s climate.

 

OCO-2 will launch on a United Launch Alliance Delta II rocket and maneuver into a 438-mile (705-kilometer) altitude, near-polar orbit. It will become the lead satellite in a constellation of five other international Earth monitoring satellites that circle Earth once every 99 minutes and cross the equator each day near 1:36 p.m. local time, making a wide range of nearly simultaneous Earth observations. OCO-2 is designed to operate for at least two years.

 

The spacecraft will sample the global geographic distribution of the sources and sinks of carbon dioxide and allow scientists to study their changes over time more completely than can be done with any existing data.

 

Since 2009, Earth scientists have been preparing for OCO-2 by taking advantage of observations from the Japanese GOSAT satellite. OCO-2 replaces a nearly identical NASA spacecraft lost because of a rocket launch mishap in February 2009.

 

At approximately 400 parts per million, atmospheric carbon dioxide is now at its highest level in at least the past 800,000 years. The burning of fossil fuels and other human activities are currently adding nearly 40 billion tons of carbon dioxide to the atmosphere each year, producing an unprecedented build-up in this greenhouse gas.