NASHUA, N.H., May 10 -- BAE SYSTEMS' Atmospheric Infrared Sounder (AIRS), built by the IR Imaging Systems (IRIS) business area in Lexington, Mass., was launched May 4 on board NASA's Aqua spacecraft from Vandenberg Air Force Base, Calif. AIRS is a high-resolution spectrometer that measures temperature and humidity by viewing the heat signature of carbon dioxide and water vapor in the atmosphere underneath the satellite's orbital path. Data from the AIRS instrument is expected to significantly improve weather forecasts, BAE SYSTEMS said. The National Weather Service, the National Oceanic and Atmospheric Administration and scientists around the world will use data collected by AIRS to better understand the Earth's climate and to improve the accuracy of their weather and climate models. The AIRS instrument is a major advance in space-based remote sensing, said the company. The 390-pound desk-sized instrument views the air column below it with more than 2,400 sensors, each tuned to observe a different color in the infrared spectrum. Much of the instrument is cooled to -180 F, and certain parts are cooled down to -355 F to achieve the high measurement sensitivity required. AIRS has more than 40,000 parts and is designed to function for up to six years in space; it operates on only 190 watts of power. According to Paul Morse, IRIS director of engineering, AIRS will make weather balloon-quality measurements of temperature and humidity twice daily over the entire globe. "It's the equivalent of launching more than 300,000 weather balloons each day," he said. "This is a thousand-fold increase in information available to computer models, and it's expected to lead to substantial improvement in mid- and long-range weather prediction."