Images: No-go for NASA on CO2 satellite

Editors' note: This slideshow was originally published February 23 at 2:59 p.m. PST, ahead of the satellite's scheduled launch later that night. We're updating it February 24 at 6:46 a.m. PST with the addition of this first photo, and information on the failure of the launch.

NASA reported early Tuesday that the spacecraft carrying the Orbiting Carbon Observatory satellite failed to reach orbit during its overnight launch. It likely landed in the Pacific Ocean after takeoff from Vandenberg Air Force Base in California, putting an end to the mission.

Editors' note: The captions that follow are from the original, prelaunch posting of the slideshow. Captions have been modified slightly as needed to reflect the failure of Tuesday's launch.

Scientists know that there's a lot more carbon dioxide in the atmosphere than there used to be in decades past. What they don't know as precisely as they'd like is where it all comes from and where it all ends up. To help put an end to that uncertainty, NASA had been looking forward to Tuesday's launch of a satellite called the Orbiting Carbon Observatory.

Over the next two years or more, the satellite (seen here in an artist's rendering) was expected to take about 8 million measurements every 16 days to provide a much more detailed picture of how carbon dioxide is distributed around the globe.

In 2007, according to NASA, the concentration of carbon dioxide in the atmosphere was approximately 383 parts per million, compared with 315 ppm in 1958 and 280 ppm three centuries earlier before the start of the Industrial Revolution. The space agency says that of all the carbons added to the atmosphere since the mid-1700s, about 40 percent has remained there, about 30 percent seems to have ended up in the oceans, and the remaining 30 percent ended up somewhere on land.

That "somewhere" is the big question mark; it's what NASA refers to as the "missing" carbon sink--a sink in this case being someplace where carbon dioxide has been removed from the atmosphere and stored. Measurements from the OCO satellite will be combined with data from other satellites, from aircraft, and from ground stations to help determine where exactly, and how efficiently, the carbon dioxide is being absorbed in land sinks.

Three high-resolution spectrometers aboard the satellite were to focus on specific, narrow color ranges that show relative amounts of carbon dioxide and molecular oxygen--essentially, more light getting through to the spectrometers means less carbon dioxide in a given area.

"Essentially, if you visualize a column of air that stretches from Earth's surface to the top of the atmosphere, the Orbiting Carbon Observatory will identify how much of that vertical column is carbon dioxide, with an understanding that most is emitted at the surface," Gregg Marland of Oak Ridge National Laboratory in Oak Ridge, Tenn., said in a NASA statement in January. "Simply, it will act like a plane observing the smoke from forest fires down below, with the task of assessing where the fires are and how big they are. Compare that aerial capability with sending a lot of people into the forest looking for fires. In this vein, the observatory will use its vantage point from space to peer down and capture a picture of where the sources and sinks of carbon dioxide are, rather than our cobbling data together from multiple sources with less frequency, reliability, and detail."

This map shows pre-OCO measurements of carbon dioxide in the atmosphere, which is seen as a major contributor to global warming. Human activities, NASA says, add about 1.4 metric tons of carbon per person per year to the atmosphere, as a worldwide average.

The OCO satellite was scheduled to lift off atop an Orbital Sciences Taurus XL rocket at just before 2 a.m. PST Tuesday from Vandenberg Air Force Base in California.

Here's a closer look at work on the launch pad. NASA planned to provide coverage on the OCO launch blog and on NASA TV starting at 12 a.m. PST. Tuesday.

The shelter at front left here, with the dome on top, is the Orbiting Carbon Observatory mobile laboratory, an Earth-bound counterpart to the OCO satellite. It's located at the ARM Climate Research Facility site in Darwin, Australia, where it will be until November 2010. Carbon dioxide measurements taken by the mobile lab's Fourier transform spectrometer were to be some of the data evaluated against findings from the orbiting observatory.