Space laser illuminates clouds - Lidar In-Space Technology Experiment aboard space shuttle - Brief Article

Science News, June 10, 1995

A powerful laser flown on the space shuttle last September captured unprecedented images of the cloud blanket enshrouding Earth, reports a team of atmospheric scientists. The laser tool, known as a lidar, offers a means of studying the natural clouds and pollution that influence the planet's climate.

A variation on radar, lidars detect objects by using laser beams instead of radio waves. Scientists routinely use ground-based lidars or fly them in airplanes to study the atmosphere. But NASA's Lidar In-space Technology Experiment (LITE) marks the first time a lidar has flown in space, says Patrick McCormick of NASA's Langley Research Center in Hampton, Va.

Pointing toward Earth from the shuttle's cargo bay, the $20 million lidar emitted a beam of light and then measured the amount that reflected off clouds and haze in the atmosphere. Unlike traditional weather satellites, LITE could penetrate high clouds to detect the lower-level ones that control weather. The lidar could also measure haze and other types of clouds invisible to weather satellites. LITE showed scientists for the first time that U.S. pollution crosses the Atlantic rather than getting cleaned out of the atmosphere by rain, as researchers had expected.

According to McCormick, the results coming from the project argue for flying a lidar on a future satellite. But it will have to compete against other promising technology for shrinking funds.