UPDATED: NASA to launch orbiting carbon observatory to study CO2

Posted by Rick C. Hodgin

Chicago (IL) - Scheduled for a 4:51:30am EST launch from Vandenberg Air Force Base in California, the Orbiting Carbon Observatory (OCO) spacecraft will be the first ever dedicated specifically to studying carbon dioxide and oxygen densities. Its mission will be to map the global distribution of CO2, the leading human-produced greenhouse gas driving climate changes, according to NASA.







An close-up view of an artist's rendition of OCO orbiting the Earth. The OCO will be part of a five-satellite "A-Train," with each satellite orbiting the earth at about the same time on successive days. Each satellite in the train will carry out specific scientific measurements on the Earth's surface and atmosphere. Click the image for additional information.





The OCO will ride atop a Taurus XL rocket, which has now been fully assembled at launch complex 576-E on Vandenberg AFB. The Taurus XL is comprised of the payload's protective fairing, as well as 1st, 2nd and 3rd stages. The OCO will not go into orbit on the space shuttle.



The OCO is NASA's new Earth-orbiting mission, sponsored by their Earth System Science Pathfinder Program. The spacecraft is designed to collect precise global measurements of carbon dioxide (CO2) in the Earth's atmosphere. Scientists will analyze OCO data to improve understandings of the natural processes and human activities regulating the abundance and distribution of the greenhouse gas. Improved understandings may enable more reliable forecasts on future changes in the abundance and distribution of CO2 in the atmosphere, as well as the effect these changes may have on the Earth's long-term climate.



According to NASA, each year 30 billion tons of carbon dioxide are released into the atmosphere through man's burning of fossil fuels, forest fires and land-use practices such as slash-and-burn. These activities have reportedly increased the CO2 levels over the past 50 years.



Currently, scientists believe about 50% to 60% of man's released CO2 is recycled back into the Earth through the ocean and land plants. The remaining 40% to 50% is believed to remain in the atmosphere.



OCO's mission will be to strictly monitor CO2 levels in the atmosphere. The craft's measurements are designed to yield monthly estimates in 1,000 square kilometer (386 square mile) swaths over the entire Earth's surface with an accuracy within 0.3% to 0.5%.



OCO will launch into a 705 kilometer (438 mile) near-polar, sun-synchronous orbit inclined 98.2 degrees to Earth's equator, mapping the globe once every 16 days. The mission is designed to last two years. It will fly in formation with the other five other NASA missions as part of the "A-Train" satellites crossing the equator each day shortly after noon. This coordinated satellite flight formation will enable researchers to correlate the observatory's data with data from the other NASA spacecraft, including nearly simultaneous CO2 measurements from the Atmospheric Infrared Sounder instrument on NASA's Aqua satellite.







OCO's sensors, shown here by colored rendering, include three parallel, high-resolution spectrometers which are tightly integrated, all fed by a common telescope. The spectrometers make simultaneous measurements of both CO2 and molecular oxygen absorption of sunlight reflected off the same location on the Earth by looking at the near-infrared spectrum. Each of the spectrometers is designed to look for specific gaps in the light wave frequencies. Since different gases absorb different colors, the instruments will be able to take common measurements of greenhouse gases, recording their full Earthly states once every 16 days.




At the time of this writing the launch clock showed a T-minus time of just over 4 days. In appearance there is nothing remarkable about OCO. Still, it is possible its short, two year mission will ask more questions than it answers.

NASA has setup an OCO launch blog to track the craft's progress. NASA's main OCO page is here.





UPDATED:  February 20, 2009 - 9:47am CST


Purdue University has published a Google Earth web-browser extension that allows one to see the Total CO2 gas as of 2002. It is a colored chart of the United States showing larger amounts of CO2 in red, and lesser amounts in a lime green.



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