Artist's rendering of NASA's Orbiting Carbon
Observatory (OCO)-2, one of five new NASA Earth science missions set to launch
in 2014, and one of three managed by JPL.
Image Credit: NASA-JPL/Caltech
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.
“Carbon dioxide in the atmosphere plays a critical role in our planet's
energy balance and is a key factor in understanding how our climate is
changing,” said Michael Freilich, director of NASA’s Earth Science Division in
Washington. “With the OCO-2 mission, NASA will be contributing an important new
source of global observations to the scientific challenge of better
understanding our Earth and its future."
NASA's Orbiting Carbon Observatory-2, launching
July 2014, will study carbon dioxide in the atmosphere and help us understand
how fast it will build up in the future.
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 buildup
in this greenhouse gas.
Greenhouse gases trap the sun's heat within Earth's atmosphere, warming the
planet’s surface and helping to maintain habitable temperatures from the poles
to the equator. Scientists have concluded increased carbon dioxide from human
activities, particularly fossil fuel burning and deforestation, has thrown
Earth's natural carbon cycle off balance, increasing global surface temperatures
and changing our planet's climate.
Currently, less than half the carbon dioxide emitted into Earth’s atmosphere
by human activities stays there. Some of the remainder is absorbed by Earth’s
ocean, but the location and identity of the natural land sinks believed to be
absorbing the rest is not well understood. OCO-2 scientists hope to coax these
sinks out of hiding and resolve a longstanding scientific puzzle.
“Knowing what parts of Earth are helping remove carbon from our atmosphere
will help us understand whether they will keep doing so in the future,” said
Michael Gunson, OCO-2 project scientist at NASA’s Jet Propulsion Laboratory
(JPL), Pasadena, California. “Understanding the processes controlling carbon
dioxide in our atmosphere will help us predict how fast it will build up in the
future. Data from this mission will help scientists reduce uncertainties in
forecasts of how much carbon dioxide will be in the atmosphere and improve the
accuracy of global climate change predictions.”
OCO-2 measurements will be combined with data from ground stations, aircraft
and other satellites to help answer questions about the processes that regulate
atmospheric carbon dioxide and its role in Earth’s climate and carbon cycle.
Mission data will also help assess the usefulness of space-based measurements of
carbon dioxide for monitoring emissions.
The observatory's science instrument features three, high-resolution
spectrometers that spread reflected sunlight into its component colors, then
precisely measure the intensity of each color. Each spectrometer is optimized to
record a different specific color absorbed by carbon dioxide and oxygen
molecules in Earth’s atmosphere. The less carbon dioxide in the atmosphere, the
more light the spectrometers detect. By analyzing the amount of light,
scientists can estimate the relative concentrations of these chemicals.
The new observatory will dramatically increase the number of observations of
carbon dioxide, collecting hundreds of thousands of measurements each day when
the satellite flies over Earth’s sunlit hemisphere. High-precision, detailed,
near-global observations are needed to characterize carbon dioxide's
distribution because the concentration of carbon dioxide varies by only a few
percent throughout the year on regional to continental scales. Scientists will
analyze the OCO-2 data, using computer models similar to those used to predict
the weather, to locate and understand the sources and sinks of carbon
dioxide.
OCO-2 is a NASA Earth System Science Pathfinder Program mission managed by
JPL for NASA's Science Mission Directorate in Washington. Orbital Sciences
Corporation in Dulles, Virginia, built the spacecraft bus and provides mission
operations under JPL’s leadership. The science instrument was built by JPL,
based on the instrument design co-developed for the original OCO mission by
Hamilton Sundstrand in Pomona, California. NASA's Launch Services Program at
NASA's Kennedy Space Center in Florida is responsible for launch management. JPL
is managed for NASA by the California Institute of Technology in Pasadena.
For more information about the Orbiting Carbon Observatory-2, visit:
and
Follow OCO-2 on Twitter at:
OCO-2 is the second of five NASA Earth science missions to be launched this
year. NASA monitors Earth’s vital signs from land, air and space with a fleet of
satellites and ambitious airborne and ground-based observation campaigns. NASA
develops new ways to observe and study Earth’s interconnected natural systems
with long-term data records and computer analysis tools to better see how our
planet is changing. The agency shares this unique knowledge with the global
community and works with institutions in the United States and around the world
that contribute to understanding and protecting our home planet.
For more information about NASA's Earth science activities in 2014,
visit:
NASA
Guillermo Gonzalo Sánchez Achutegui
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