February 22, 2011

Glory Set For Wednesday Launch

NASA is scheduled to launch its latest Earth-orbiting satellite -- Glory -- in the predawn hours early Wednesday in what is to be a $424 million mission to observe and analyze airborne particles emitted from volcanoes, forest fires, smokestacks and tailpipes.

The satellite will be launched from Vandenberg Air Force Base in Santa Barbara County, California. It will be carried by a Taurus XL rocket into space about 440 miles above Earth, where it will join a fleet of satellites that has been collecting data on climate for years.

The main job of Glory will be to study fine airborne particles known as aerosols. Aerosols -- smaller than the diameter of a human hair -- can travel vast distances across the globe in the atmosphere and are largely responsible for producing hazy skies.

Not much is known about aerosols and the effect they have on the climate. Scientists hope Glory will provide a better understanding of how the aerosols affect the climate in turn offering better ways to improve climate models.

"We need to know these particles much better than we do," project scientist Michael Mishchenko, of the NASA Goddard Institute for Space Studies, told The Associated Press (AP).

Average temperatures have risen 1.4 degrees Fahrenheit worldwide over the past hundred years. Scientists blame carbon dioxide -- mostly due to burning of coal, oil and other fossil fuels -- as the primary cause of global warming.

Unlike greenhouse gases that remain in the atmosphere for years, aerosols are relatively short-lived, making it much harder to measure them than carbon dioxide. Roughly 90 percent of aerosols come from natural sources such as volcanic ash, desert dust and smoke from forest fires. The remaining 10 percent comes from human activities.

Aerosols can influence both warming and cooling of the planet depending on their chemical makeup. They can result in cooling by scattering sunlight back into space; and can also absorb solar energy, warming the atmosphere.

Aerosols have been studied by numerous other satellites, but Glory is designed to make the most accurate measurements from space by studying how widely distributed they are and what types of chemical makeup they have.

Glory will also monitor changes in solar activity to determine the sun's effect on climate.

Glory, which weighs roughly 900 pounds, will be launched aboard a 4-stage Taurus XL rocket built by Orbital Sciences Corp. It will be Taurus XL's first flight since a 2009 launch failure that resulted in the loss of a NASA global warming satellite.

Glory will operate in orbit for at least three years. The mission was scheduled for launch last November, but a problem with solar panels grounded the launch by three months. Once in low-Earth orbit, the satellite will join a number of other satellites already collecting climate data.


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