Sensor built by USU team readied for launch

Instrument uses light to measure gases in ozone

By Andrew Kirk
Deseret News
June 24, 2004

A Utah State University designed instrument that uses light to measure gases will take a look from space at ozone and chemicals in the Earth's atmosphere starting next month.

The Tropospheric Emission Spectrometer will be launched from Vandenberg, Calif., July 8 in NASA's Aura satellite.

The sensor sorts light into infrared colors to measure chemicals passing between the troposphere, nearest the Earth, and the stratosphere.

According to Anderson, 90 percent of the ozone is in the high up stratosphere, but harmful chemicals like Freon are seeping up into it and other chemicals are coming down from it.

Scientists want to better understand this flow to see if current regulations on harmful chemicals are allowing the ozone to recover, he said.

The sensor will split light into a spectrum. Because each chemical absorbs or emits different kinds of light, which "colors" are brightest and where they are on the spectrum will allow scientists to determine the quantity of each chemical in the atmosphere.

The "colors" are invisible to the human eye and very difficult to detect because heat levels may disrupt the sensors ability to see light levels, Anderson said.

This heat problem is a large part of what made the instrument so difficult to make, said optical engineer Blake Crowther.

Each of the three major parts of the instrument needs a different temperature to work properly.

"Many parts had to be custom designed," Crowther said, adding that nearly every part of the satellite was built in a different part of the country. NASA's Jet Propulsion Laboratory assembled the pieces.

Although completed in 2000, the USU team has had to wait until now for a launch. The launch is "what you worked all these years for — to see it go up," Crowther said. "It's finally ready, and I'm excited to see it perform and the data to come from it."

Long delays are common in space research, he said, because not every piece is completed at the same time, funding can be erratic and final testing must be thorough.

"The space launch business just functions that way," he said.

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